WO2025216883A1 - Implantable medical device delivery system and method - Google Patents

Abstract

A delivery system and method are described that include a catheter and an active wire. The catheter has a catheter body that defines a primary lumen and a secondary lumen therethrough, which are spaced apart from each other. A distal end of the catheter body is configured to be located within a chamber of a heart proximate to myocardial tissue at a site of interest (SOI). The primary lumen has a greater cross-sectional size than the secondary lumen. The primary lumen is configured to receive at least a portion of an IMD therein and to permit the portion of the IMD to move relative to the catheter. The active wire is configured to extend through the secondary lumen so that a distal end of the active wire projects beyond the distal end of the catheter body to pierce the myocardial tissue at the SOI.

Description

IMPLANTABLE MEDICAL DEVICE DELIVERY

SYSTEM AND METHOD

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63/631 ,854, filed April 9, 2024, which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

[0002] Embodiments of the present disclosure relate generally to systems and methods for implanting medical devices (IMDs) within a patient, such as delivery systems for implanting cardiac leads.

BACKGROUND

[0003] Delivery systems are used to implant IMDs within subjects (e.g., patients). The IMD may function to monitor cardiac activity of the subject, provide electrotherapy to cardiac tissue, and/or the like. Cardiac pacemakers and implantable cardioverter-defibrillators (ICD) use insulated wires called leads to monitor the heart and to also provide stimulation therapy by delivering electrical pacing pulses and/or shocks. Leadless pacemakers can monitor the heart and deliver stimulation therapy without the use of leads. The delivery systems may include guide catheters that transport the entire IMD or a portion of the IMD through an access introducer into the subject. As examples, a catheter may deliver a cardiac lead or a leadless pacemaker. The catheter may navigate the venous system and/or cardiac anatomy to position the IMD, or portion thereof, at a target anatomical location. For example, the IMD may be transported within a lumen of the catheter. Upon placement of the IMD at the target anatomical location, the catheter is withdrawn from the subject while the IMD remains.

[0004] Removing the catheter without inadvertently displacing the IMD or the portion of the IMD can be challenging. For example, cardiac leads are thin and, when finally positioned, may have a number of bends or twists along its path. Furthermore, the proximal end of the lead typically includes a connector that is relatively large and forms an obstruction. The operator must be diligent when withdrawing the catheter so that the catheter does not strike the connector at the proximal end and dislodge the lead from its desired long-term implant location. If the lead is dislodged, the lead-implantation procedure must begin again. Repeating the process increases the risk of infection in addition to other complications that may arise during such medical procedures.

[0005] Several conduction system pacing (CSP) implant procedures involve fixating (e.g., securing) a pacing lead to myocardial tissue of the heart to allow a distal end of the pacing lead to reach a desired implant site. The implant site in examples may include the right ventricle apex or the ventricular septal wall, element of the subject’s conduction system. The septal wall may be selected as the implant site to reach the His-Purkinje system (e.g., the His bundle) of the heart. His-bundle pacing (HBP) uses native conduction pathways and could promote ventricular synchrony. It remains challenging, however, to locate the His bundle and achieve true selective capture. In general, even upon reaching the septal wall, some implant locations and depths along the septal wall provide better conduction of electrical stimulation than other locations and depths. It is difficult for an operator to determine if a current implant location of the IMD or lead thereof is better than another location nearby.

[0006] As a result, it is common for an operator to make several implant revisions of the IMD or lead during the implant procedure in an effort to discover an optimal therapy site. Each implant revision entails removing the IMD or lead thereof from the patient myocardial tissue, repositioning the distal end of the catheter to approach another location of the myocardial tissue, and then fixating the IMD or the lead thereof to the other location. The operator may control a programmer device (e.g., a pacing system analyzer) to deliver electrical stimulation through the IMD to the cardiac tissue at each location to test and compare the evoked responses to the electrical stimulation. The implant revisions are invasive and undesirably increase patient risk, as well as risk damage to the IMD or lead itself. For example, a fixation element at the distal end of an IMD or lead thereof may be relatively large, so piercing the myocardial tissue with such a fixation element at multiple different locations may increase damage and trauma to the tissue. Furthermore, repeated coupling and uncoupling of the fixation element to the myocardial tissue may involve repeated advancing and retracting of the IMD within the catheter, which risks damaging or weakening the IMD or the lead.

[0007] A need remains for a delivery system that avoids at least some of the issues with known IMD implant procedures. For example, a need remains for delivery systems that provide more efficient and less invasive IMD implant procedures, while allowing for investigating multiple sites before selecting a longterm implant location.

SUMMARY

[0008] In accordance with embodiments herein, a delivery system is provided that includes a catheter and an active wire. The catheter includes a catheter body that has a distal end configured to be located within a chamber of a heart proximate to myocardial tissue at a site of interest (SOI). The catheter body defines a primary lumen and a secondary lumen therethrough. The primary and secondary lumens are spaced apart from each other. The primary lumen has a greater cross-sectional size than the secondary lumen and is configured to receive at least a portion of an implantable medical device (IMD) therein and to permit the portion of the IMD to move relative to the catheter. The active wire is configured to extend through the secondary lumen of the catheter body. The active wire includes a tip electrode at a distal end of the active wire. The active wire is configured to be moved through the secondary lumen so that the distal end of the active wire projects beyond the distal end of the catheter body to pierce the myocardial tissue at the SOI.

[0009] In accordance with embodiments herein, a method for delivering an IMD or a portion of an IMD to patient cardiac tissue is provided. The method includes loading a catheter into a chamber of a heart proximate to myocardial tissue at a first site of interest (SOI). The catheter includes a catheter body that defines a primary lumen and a secondary lumen therethrough. The primary and secondary lumens are spaced apart from each other. The primary lumen has a greater cross-sectional size than the secondary lumen and is configured to receive at least a portion of an IMD therein and to permit the portion of the IMD to move relative to the catheter. The method includes advancing an active wire through the secondary lumen of the catheter body so that a distal segment of the active wire pierces the myocardial tissue at the first SOI. The distal segment of the active wire includes a tip electrode. The method includes advancing at least a portion of an implantable medical device (IMD) through the primary lumen of the catheter body so that a distal end of the portion of the IMD secures to the myocardial tissue next to the distal segment of the active wire. The method includes retracting the active wire into the secondary lumen so that the distal segment exits the myocardial tissue, and withdrawing the catheter and the active wire from the chamber of the heart while the portion of the IMD remains secured to the myocardial tissue.

[0010] In accordance with embodiments herein, a delivery system is provided that includes a catheter and an active wire. The catheter includes a catheter body and a catheter electrode. The catheter body has a distal end configured to be located within a chamber of a heart proximate to myocardial tissue at a site of interest (SOI). The catheter body defines a primary lumen and a secondary lumen therethrough. The primary and secondary lumens are spaced apart from each other. The primary lumen has a greater cross-sectional size than the secondary lumen. The primary lumen is configured to receive a lead therein and to permit the lead to move relative to the catheter. The catheter electrode is located at or proximate to the distal end of the catheter body. The active wire is within the secondary lumen of the catheter body. The active wire includes a tip electrode at a distal end of the active wire. The active wire is configured to be moved relative to the catheter to advance a distal segment of the active wire beyond the distal end of the catheter body to pierce the myocardial tissue at the SOI. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 illustrates a schematic cutaway view of a heart relative to an IMD.

[0012] Figure 2 is another schematic cutaway view of the heart showing a location of the bundle of His (e.g., His bundle) in the heart.

[0013] Figure 3A illustrates a delivery system that includes a catheter formed in accordance with an embodiment.

[0014] Figure 3B illustrates a second delivery system that includes a catheter formed in accordance with an embodiment

[0015] Figure 4 illustrates a distal end segment of a catheter of the delivery system according to an embodiment.

[0016] Figure 5 illustrates the distal end segment of the catheter holding an active wire and a lead according to an embodiment.

[0017] Figure 6 shows a portion of the active wire projecting beyond a distal end of a catheter body.

[0018] Figure 7 illustrates the active wire of the delivery system according to an embodiment.

[0019] Figure 8 shows a distal segment of the lead projecting beyond the distal end of the catheter body.

[0020] Figure 9 illustrates another orientation of the distal end segment of the catheter.

[0021] Figure 10 is a perspective view of the distal end segment of the catheter of the delivery system according to a second embodiment.

[0022] Figure 11 is a perspective view of the distal end segment of the catheter shown in Figure 10 with an annular inflatable balloon in an inflated state.

[0023] Figure 12 is a side view of the distal end segment of the catheter shown in Figures 10 and 11 with the annular inflatable balloon in the inflated state. [0024] Figure 13 is a perspective view of the distal end segment of the catheter of the delivery system according to a third embodiment.

[0025] Figure 14 is a side view of the distal end segment of the catheter shown in Figure 13.

[0026] Figure 15A is a side view of the distal end segment of the catheter of the delivery system according to a fourth embodiment.

[0027] Figure 15B is a side view of the distal end segment of the catheter of

Figure 15A with a deflectable sheath in a flared state.

[0028] Figure 16 is a perspective view of the distal end segment of the catheter of Figures 15A and 15B with the deflectable sheath in the flared state.

[0029] Figure 17 illustrates a connector device of the delivery system coupled to the active wire according to an embodiment.

[0030] Figure 18 shows the connector device of Figure 17 without spring clips.

[0031] Figure 19 is a cross-sectional view showing the active wire within a hub segment of the connector device according to an embodiment.

[0032] Figure 20 is an elevation view showing a distal end of the connector device of Figure 19.

[0033] Figure 21 illustrates the connector device according to an embodiment that includes a rotatable locking mechanism.

[0034] Figure 22 is a flowchart of a method of delivering an IMD or a portion of an IMD to cardiac tissue within a patient according to an embodiment.

[0035] Figure 23 illustrates the distal end segment of the catheter within a heart chamber and pressed against a septal wall at a first site of interest (SOI).

[0036] Figure 24 illustrates the distal end segment of the catheter with the active wire projecting beyond the catheter body into the septal wall at the first SOI. [0037] Figure 25 illustrates the distal end segment of the catheter positioned proximate to a second SOI that is selected as a target implant location.

[0038] Figure 26 illustrates a block diagram of an exemplary IMD that is configured to be implanted into the patient in accordance with one or more embodiments herein.

DETAILED DESCRIPTION

[0039] It will be readily understood that the components of the embodiments as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations in addition to the described example embodiments. Thus, the following more detailed description of the example embodiments, as represented in the figures, is not intended to limit the scope of the embodiments, as claimed, but is merely representative of example embodiments.

[0040] Reference throughout this specification to “one embodiment” or “an embodiment” (or the like) means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” or the like in various places throughout this specification are not necessarily all referring to the same embodiment.

[0041] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that the various embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obfuscation. The following description is intended only by way of example, and simply illustrates certain example embodiments. [0042] The methods described herein may employ structures or aspects of various embodiments (e.g., systems, devices, and/or methods) discussed herein. In various embodiments, certain operations may be omitted or added, certain operations may be combined, certain operations may be performed simultaneously, certain operations may be performed concurrently, certain operations may be split into multiple operations, certain operations may be performed in a different order, or certain operations or series of operations may be re-performed in an iterative fashion. It should be noted that, other methods may be used, in accordance with an embodiment herein. Further, wherein indicated, the methods may be fully or partially implemented by one or more processors of one or more devices or systems. While the operations of some methods may be described as performed by the processor(s) of one device, additionally, some or all of such operations may be performed by the processor(s) of another device described herein.

[0043] Embodiments may be implemented in connection with one or more implantable medical devices (IMDs). Non-limiting examples of IMDs include neurostimulator devices, implantable leadless monitoring and/or therapy devices, catheters, and/or alternative implantable medical devices. For example, the IMD may represent a cardiac monitoring device, pacemaker, cardioverter, cardiac rhythm management device, defibrillator, neurostimulator, leadless monitoring device, leadless pacemaker and the like. For example, the IMD may include one or more structural and/or functional aspects of the device(s) described in U.S. Patent 9,333,351 “Neurostimulation Method And System To Treat Apnea” and U.S. Patent 9,044,610 “System And Methods For Providing A Distributed Virtual Stimulation Cathode For Use With An Implantable Neurostimulation System”, which are hereby incorporated by reference.

[0044] All references, including publications, patent applications and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0045] Embodiments set forth herein include delivery systems for implanting IMDs, and methods for using the same. Particular embodiments of the delivery system include a catheter that has multiple lumens. The lumens extend through a body of the catheter along a length of the catheter. A first or primary lumen of the catheter is sized to receive an IMD therein, or a portion of the IMD. The portion of the IMD may be a lead (e.g., a pacing lead). The IMD may be a leadless pacemaker or the like. Various examples described herein refer to the payload within the primary lumen as a lead. The lead may provide pacing pulses to cardiac tissue. For example, the lead may be used in CSP applications. However, in other applications a leadless IMD may be held within the primary lumen and delivered through the primary lumen of the catheter to a target implant location.

[0046] A second or secondary lumen of the catheter is sized to receive an active wire therein. The active wire within the secondary lumen may be independently movable within the catheter relative to the IMD or lead within the primary lumen, and vice-versa. The active wire includes one or more electrodes at a distal end of the active wire. The electrode(s) at the distal end may assist with testing a site of interest (SOI) prior to fixating (e.g., securing) the IMD or lead into the cardiac tissue. For example, the electrode(s) can assist in conduction system pacing in which the active wire is inserted through the septal wall to access the conduction system for pacing therapy.

[0047] Embodiments of the delivery system described herein provide an active wire that is designed to assist a physician with finding a desirable implant site for a lead of an IMD or a leadless IMD. The desirable implant site may be a pacing site for the lead or IMD to provide pacing stimulation therapy. The active wire may be a thin, minimally-invasive wire that is unipolar, bipolar, or multipolar. The active wire may be significantly thinner than a fixation element of a lead or leadless IMD, so iterative penetration of the distal end of the active wire into the cardiac tissue to find the desirable implant site has a lower risk of perforation (e.g., damage) than iterative implantation of a lead or an IMD.

[0048] The delivery system described herein provides several beneficial technical effects. The delivery system allows an operator to quickly and relatively easily determine whether a current location of the distal end of the catheter adjacent cardiac tissue of the patient’s heart is suitable for use as a long-term implant location without trauma to the cardiac tissue. For example, the delivery system enables investigating a SOI without securing the lead or IMD to the cardiac tissue. Instead, the active wire is advanced to project beyond the distal end of the catheter and pierce the cardiac tissue. A pulse generator may be used to deliver electrical stimulation therapy to the cardiac tissue and/or monitor an evoked response to the electrical stimulation therapy using at least one electrode of the active wire. The pulse generator may be a component of a pacing system analyzer or another pacing system. The lead or IMD does not penetrate the cardiac tissue during this testing. For example, the lead or IMD may be housed within the primary lumen of the catheter at this time. To test additional sites, the operator may retract the active wire from the cardiac tissue, reposition the distal end of the catheter to a second site, advance the active wire to pierce the cardiac tissue at the second site, and then control the pulse generator to deliver additional electrical stimulation and monitor the evoked response using the at least one electrode of the active wire. The lead or the IMD may only be secured to the cardiac tissue after determining the long-term implant location based on the investigation.

[0049] Another technical effect of the delivery system described herein is that the delivery system may permit temporary bipolar pacing at each SOI to aid in selecting the long-term implant location. For example, a tip electrode at the distal end of the active wire may function as one electrode of a bipolar electrode pair. The catheter may include an electrode, which is referred to herein as a catheter electrode to distinguish from electrodes of other components. The catheter electrode may be located at or proximate to the distal end of the catheter. The catheter electrode may function as the other electrode in the bipolar electrode pair. For example, the tip electrode on the active wire may function as a cathode, and the catheter electrode may function as an anode, or vice-versa. The delivery system may use the bipolar electrode pair for delivering electrical stimulation energy to the cardiac tissue and/or sensing evoked responses from the cardiac tissue in response to the electrical stimulation energy. Thus, the testing of various potential implant locations may be performed without the use of any electrodes on the lead or the IMD. Optionally, the lead or IMD may not even be loaded into the catheter during the site investigation/testing procedure. Optionally, the lead or IMD may be loaded at least partially in the primary lumen without projecting beyond the distal end of the catheter during the site investigation. In a second example, the temporary bipolar pacing may be provided using the tip electrode of the active wire and an electrode at the distal end of the lead or IMD, instead of using a catheter electrode. In a third example, the active wire may include multiple electrodes spaced apart along a distal segment of the active wire, and at least two of the electrodes can provide the temporary bipolar pacing.

[0050] Figure 1 illustrates a schematic cutaway view of a heart 10 relative to an IMD 50. The heart 10 includes a right atrium RA, a right ventricle RV, a left atrium LA, and a left ventricle LV. During normal operation of the heart 10, deoxygenated blood from the body is returned to the right atrium RA from the superior vena cava 12 and inferior vena cava 14. The right atrium RA pumps the blood through the atrioventricular or tricuspid valve 16 to the right ventricle RV, which then pumps the blood through the pulmonary valve 18 and the pulmonary artery 20 to the lungs for reoxygenation and removal of carbon dioxide. The newly oxygenated blood from the lungs is transported to the left atrium LA, which pumps the blood through the mitral valve 22 to the left ventricle LV. The left ventricle LV pumps the blood through the aortic valve 24 and the aorta 26 throughout the body.

[0051] Figure 2 is another schematic cutaway view of the heart 10 showing a location of the bundle of His 30 (e.g., His bundle) in the heart. The His bundle 30 consists of fast-conducting muscle fibers that begin at the atrioventricular node in the right atrium and pass to the interventricular septum. The His bundle 30 divides in the septum into a right branch that travels along the right side of the septum and supplies excitation to the right ventricle, and a pair of left branches that travel along the left side of the septum and supply excitation to the left ventricle. The fibers in the branches terminate in an extensive network of Purkinje fibers which distribute excitation pulses to the layer of cells beneath the endocardium.

[0052] Returning to Figure 1 , the IMD 50 includes a pulse generator 52 that is operably coupled to a lead 54 through a lead adaptor 56. The lead adaptor 56 is configured to receive a lead connector (not shown) of the lead 54. Although the IMD 50 includes only one lead in Figure 1 , the IMD 50 may include multiple leads in other embodiments. The lead 54 is designed to penetrate the endocardium in contact with His bundle 30. The lead 54 may enter the vascular system through one of several possible vascular access sites. The lead 54 may extend through the superior vena cava 12 to the right atrium RA.

[0053] In Figure 1 , the IMD 50 is a cardiac pacemaker. In other embodiments, however, the IMD 50 may include an ICD, a CRT-D, an ICD coupled with a pacemaker, and the like. The IMD 50 may be a dual-chamber stimulation device capable of treating both fast and slow arrhythmias with stimulation therapy, including cardioversion, defibrillation, and pacing stimulation, as well as capable of detecting heart failure, evaluating its severity, tracking the progression thereof, and controlling the delivery of therapy and warnings in response thereto. The IMD 50 may be controlled to sense atrial and ventricular waveforms of interest, discriminate between two or more ventricular waveforms of interest, deliver stimulus pulses or shocks, and inhibit application of a stimulation pulse to a heart based on the discrimination between the waveforms of interest and the like.

[0054] Although not shown, the IMD 50 may wirelessly communicate with an external device. The external device may be used by a physician or other technician to select and/or modify therapy parameters to be implemented by the IMD 50.

[0055] Figure 3A illustrates a delivery system 100 formed in accordance with an embodiment. The delivery system 100 in the illustrated embodiment includes a catheter (or introducer sheath) 101 , a handle 104, a connector assembly 106, and a fluid flushing assembly 108. Not all of the elements shown in Figure 3A are mandatory for a delivery system 100 according to the embodiments described herein. For example, Figure 3B shows a second delivery system 123 according to another embodiment. The delivery system 123 in Figure 3B has a catheter 126 and a hub 128. For example, the handle 104, the connector assembly 106, and the fluid flushing assembly 108 shown in Figure 3A may be optional components.

[0056] Referring to Figure 3A, the connector assembly 106 includes an electrical connector 110. In an example, the electrical connector 110 may be electrically connected to one or more electrodes of the delivery system 100. For example, the electrical connector 110 may be coupled to a proximal end of an active wire 200 (shown in Figure 5) and electrically connected to one or more electrodes of the active wire, as described in more detail herein. The connector assembly 106 may selectively communicatively connect to a pacing system analyzer device 111. The pacing system analyzer device 111 , as explained herein, may use the delivery system 100 to electrically map multiple sites of interest (SOI) along patient cardiac tissue to select a long-term implant location for an IMD or a lead thereof. For example, the pacing system analyzer device 111 may include a pulse generator, a memory device, and processing circuitry. The processing circuitry may control the pulse generator to generate a pacing pulse that are delivered by one or more electrodes of the active wire to myocardial tissue at a SOI. The processing circuitry may then analyze signals indicative of an evoked response in the myocardial tissue to the pacing pulse.

[0057] The handle 104 may include a hemostasis hub 112 for accepting and coupling to (e.g., tethering to) a proximal end 114 of the catheter 101 . The catheter 101 extends from the proximal end 114 to a distal end 116 of the catheter 101. In an embodiment, the catheter 101 has multiple, i.e., at least two, lumens. The lumens extend through the catheter 101 from the proximal end 114 to the distal end 116. The lumens may be open at both ends 114, 116. The hemostasis hub 112 permits access to the lumens of the catheter 101. The fluid flushing assembly 108 may mechanically couple to the hemostasis hub 112 and fluidly couple to the catheter lumens through the hemostasis hub 112.

[0058] The catheter 101 is configured to introduce both the active wire and a lead of an IMD (or an entire IMD) into a designated anatomical region of a patient (e.g., the heart). For example, the active wire may be loaded through one of the lumens of the catheter 101 , and a lead may be loaded through another lumen of the catheter 101 . The catheter 101 may be steerable to navigate through a tortuous vascular system of the patient. The catheter 101 may be steered to position a distal end segment 103 of the catheter 101 proximate to a SOI, with the end of the catheter 101 facing the myocardial (e.g., cardiac) tissue at the SOI. The catheter 101 may include a plurality of sheath segments or portions along its length, and at least some of the sheath segments may be bendable relative to other sheath segments. An operator may steer the catheter 101 by holding the handle 104 and manipulating at least one actuator 135 coupled to the handle 104. Based on its intended use, the catheter 101 may be designed to exhibit various properties. For example, the catheter may be maneuverable and have a sufficient columnar strength for being inserted through the tortuous vascular system. The catheter may also have sufficient kink-resistance so as to bend smoothly.

[0059] The delivery system 100 may also include an obturator/dilator. A distal end of the obturator/dilator may be wedge-shaped or cone-shaped (e.g., conical). The obturator/dilator may be used to enlarge an opening (e.g., incision) for access to the vascular system and/or to provide support for the catheter 101 as the catheter 101 is being maneuvered. [0060] Figure 3B illustrates a second delivery system 123 that includes a catheter 126 formed in accordance with an embodiment. The delivery system 123 may be an alterative to the delivery system 100 shown in Figure 3A. The delivery system 123 includes the catheter 126 and a hub 128 connected to a proximal end 130 of the catheter 126. The catheter 126 extends from the hub 128 to a distal end 132 of the catheter 126. The hub 128 may include a fluid flushing port 134. The hub 128 may form a hemostasis seal around the outer surface of the catheter 126 at the proximal end segment thereof.

[0061] The catheter 126 may be similar to the catheter 101 shown in Figure 3A. For example, the catheter 126 may define multiple lumens extend through the catheter 126 from the proximal end 130 to the distal end 132. The lumens may be open at both ends 130, 132. The hub 128 permits access to the lumens of the catheter 126 for the active wire and a lead of an IMD (or the IMD itself). For example, the active wire may be loaded through one of the lumens of the catheter 126, and a lead may be loaded through another lumen of the catheter 126. The fluid flushing port 134 may fluidly couple to the catheter lumens to permit flushing saline through the catheter 126 to make the lead easier to advance.

[0062] In an embodiment, the catheter 126 may have a static, fixed shape. The catheter 126 may have a predefined curvature along a distal segment. The curvature may be selected to enable the catheter 126 to maneuver through the patient vasculature to a specific target implant area. As an example, the target implant area may be on the septal wall of the RV.

[0063] Figure 4 illustrates a distal end segment 124 of a catheter 102 according to an embodiment. The catheter 102 may be the catheter 101 shown in Figure 3A or the catheter 126 shown in Figure 3B. When the catheter 102 represents the catheter 101 , the distal end segment 124 may be the distal end segment 103 shown in Figure 3A. [0064] The catheter 102 includes a catheter body 140. The catheter body 140 may extend the length of the catheter 102. The catheter body 140 extends from a proximal end of the catheter body 140 to a distal end 142 of the catheter body 140. The proximal end of the catheter body 140 may be at or proximate to the proximal end 114 of the catheter 102 shown in Figure 3A. The distal end 142 of the catheter body 140 may be at or proximate to the distal end 116 of the catheter 102. The catheter body 140 extends lengthwise along a central axis 144 of the catheter body 140 from the proximal end to the distal end 142. The central axis 144 may extend along a curved path that changes as the catheter 102 is flexed, bent, twisted, or otherwise manipulated.

[0065] The catheter body 140 defines a first lumen 146 and a second lumen 148. The first lumen 146 is referred to as a primary lumen 146 herein, and the second lumen 148 is referred to as a secondary lumen 148. Both lumens 146, 148 extend lengthwise along the catheter body 140. For example, the lumens 146, 148 may extend parallel to each other and parallel to the central axis 144. The primary lumen 146 is discrete and spaced apart from the secondary lumen 148, i.e., is spatially separated from the secondary lumen 148. For example, the catheter body 140 may have an intervening wall 150 that separates the primary lumen 146 from the secondary lumen 148 along the length of the catheter body 140. In an example, the first lumen 146 is isolated (e.g., fluidly disconnected) from the second lumen 148 along the length of the catheter body 140. The first and second lumens 146, 148 may be open at the distal end 142 of the catheter body 140. For example, the catheter body 140 has a first access opening 152 to the primary lumen 146 at the distal end 142 and a second access opening 154 to the secondary lumen 148 at the distal end 142. The lumens 146, 148 may also be open at the proximal end of the catheter body 140.

[0066] The primary lumen 146 has a greater cross-sectional size than the secondary lumen 148. For example, when a cross-section is taken of the catheter body 140 that is perpendicular to the central axis 144 at the section plane, the primary lumen 146 has a greater size dimension along the section plane than the secondary lumen 148. In an example, the primary lumen 146 and the secondary lumen 148 are both cylindrical with circular cross-sectional shapes, so the primary lumen 146 has a larger diameter than the secondary lumen 148. In another example, at least one of the primary lumen 146 or the secondary lumen 148 may have an elliptical or oval shape. In an example, the dimension of the primary lumen 146 may be 4 French (F) to 9 F (4/3=1 .33 mm to 9/3=3 mm). The dimension of the secondary lumen 148 may be 1 F to 3 F (1/3=0.33 mm to 3/3=1 mm). In an example, the size of the primary lumen 146 may be at least twice the size of the secondary lumen 148.

[0067] In an embodiment, the primary lumen 146 is sized to receive a lead of an IMD therein. The primary lumen 146 is sized to permit the lead to move relative to the catheter 102. For example, if the lead has a diameter or thickness of 6 F (6/3=2 mm), the primary lumen 146 may be sized to have a cross-sectional size of at least 7 F (7/3=2.33 mm) or 8 F (8/3=2.67 mm) to reduce friction between the lead and the inner surface of the catheter body 140 within the primary lumen 146. In an embodiment, the secondary lumen 148 is sized to receive an active wire therein. The secondary lumen 148 is sized to permit the active wire to move relative to the catheter 102. For example, if the active wire has a diameter or thickness of 2 F (2/3=0.67 mm), the secondary lumen 148 may be sized to have a cross- sectional size of 3 F (3/3=1 mm) to reduce friction between the active wire and the inner surface of the catheter body 140 within the secondary lumen 148.

[0068] Figure 5 illustrates the distal end segment 124 of the catheter 102 holding an active wire 200 and a lead 202 according to an embodiment. The active wire 200 is disposed within the secondary lumen 148 of the catheter body 140. The lead 202 is disposed within the primary lumen 146. The active wire 200 can be advanced through the secondary lumen 148 to project beyond the distal end 142 of the catheter body 140 to pierce patient myocardial tissue at a SOI. In one example application, the myocardial tissue at the SOI may be a ventricular septal wall (for left bundle branch area pacing). In another application, the myocardial tissue may be a right ventricular apex. The active wire 200 may be moved relative to the catheter body 140 via manipulation of an actuator of the delivery system 100 shown in Figure 3A. The active wire 200 and the lead 202 are both be located within the catheter body 140 in Figure 5 without projecting beyond the distal end 142. In an example, the catheter 102 may be maneuvered through the vascular system of the patient with the active wire 200 and the lead 202 held within the corresponding lumens 148, 146 as shown in Figure 5. Alternatively, the active wire 200 and/or the lead 202 may be loaded into the corresponding lumens 148, 146 after the catheter body 140 is maneuvered at least part of the way to the cardiac tissue at the SOI.

[0069] Figure 6 shows a distal end 210 of the active wire 200 projecting beyond the distal end 142 of the catheter body 140. The active wire 200 is partially disposed within the secondary lumen 148. The active wire 200 includes an electrode 212 at the distal end 210. The electrode 212 is referred to herein as a tip electrode because the electrode 212 is located at a tip or end portion of the active wire 200. When in the projecting position shown in Figure 6, the distal end 210 is designed to pierce the cardiac tissue at the SOI. For example, the tip electrode 212 may have a rounded, conical, and/or tapered shape that permits the distal end 210 to pierce the cardiac tissue with relatively minor applied force to the active wire 200. The active wire 200 may have a relatively thin diameter, such as 3 F (1 mm), 2 F (2/3=0.67 mm), or 1 F (1/3=0.33 mm). In an alternative embodiment, the active wire 200 may include a fixation anchor at the distal end. The fixation anchor may be a helical screw element, a hook, or the like.

[0070] Figure 7 illustrates the active wire 200 of the delivery system 100 according to an embodiment. The active wire 200 extends from the distal end 210 to a proximal end 216 of the active wire 200. In an example, the active wire 200 includes a wire body 214, the tip electrode 212, one or more ring electrodes 218, and terminal connector rings 220. The active wire 200 may have a distal segment 222 that extends to the distal end 210, a proximal segment 224 that extends to the proximal end 216, and a medial segment that is between the distal segment 222 and the proximal segment 224. Optionally, the medial segment may be longer than the distal and proximal segments 222, 224. Most of the medial segment is omitted in Figure 7. The length of the medial segment may be selected based on application-specific parameters and considerations, such as the size of the patient, the implant path through the patient, and/or the like.

[0071] The active wire 200 may be an active mapping electrode wire. The electrodes 212, 218 at the distal segment 222 can assist in conduction system pacing and/or investigating implant sites. The electrodes 212, 218 are capable of pacing and/or sensing. The active wire 200 may provide at least one of a unipolar, bipolar, or multipolar system. The electrodes 212, 218 at the distal segment 222 at the myocardial tissue are electrically connected to the terminal connector rings 220 at the proximal end 224. Each terminal connector ring 220 is electrically connected to a different corresponding one of the electrodes 212, 218. For example, the active wire 200 may include electrical lines (e.g., wires) within the wire body 214 that electrically connect the terminal connector rings 220 to the electrodes 212, 218. The terminal connector rings 220 may electrically connect to clip connectors of a pacing system analyzer during the implant site investigation process. The clip connectors may be alligator clips, crimped or welded portions of cables, and/or the like. In an example, the delivery system 100 may include a connector device 230 (shown in Figure 17) to assist the physician or other technician with electrically connecting the terminal connector rings 220 to the clip connectors of the pacing system analyzer.

[0072] In the illustrated example, the active wire 200 has three ring electrodes 218. The ring electrodes 218 are spaced apart from each other and the tip electrode 212 along the length of the active wire 200. In an example, the spacing between the ring electrodes 218 and the tip electrode 212 may be up to 5 mm. The spacing may be greater than 5 mm in other example embodiments. The active wire 200 having multiple spaced-apart electrodes 212, 218 at the distal segment 222 may be beneficial for accessing different depths within the myocardial tissue. For example, the distal segment 222 may be insertable through the septal wall approximately 10 to 20 millimeters to test different SOI for discovering a preferred implant site for pacing therapy. At a first depth in the septal wall, only a first (e.g., distal-most) ring electrode 218 may penetrate the myocardial tissue. At a second depth in the septal wall, both the first and a second ring electrode 218 may penetrate the myocardial tissue. The operator (e.g., physician) may connect the pacing system analyzer to different terminal connector rings 220 associated with the different ring electrodes 218 to selectively use the ring electrodes 218 for delivering pacing pulses and/or sensing evoked responses.

[0073] Furthermore, the pacing system analyzer may determine the current depth of the active wire 200 in the myocardial tissue based on a determination of which and/or how many of the ring electrodes 218 are currently embedded within the myocardial tissue. For example, the ring electrodes 218 may be spaced apart at known distances and/or locations along the length of the active wire 200. Based on the electrical signals received from the terminal connector rings 220 associated with the different ring electrodes 218, the pacing system analyzer (e.g., the operator) can detect which of the ring electrodes 218 is within the septal wall, for example, and which other ring electrodes 218 are outside of the septal wall. Using this information and the know locations of the ring electrodes 218, the current implant depth of the active wire 200 can be determined. The current implant depth can be used by the operator to determine, for example, a depth that the lead will need to be inserted into the tissue (e.g., septal wall) to reach the target implant site. For example, the spaced-apart ring electrodes 218 can be used to determine that the target implant site to reach the left bundle branch is 10 mm into the septal wall at the current location of the delivery system 100.

[0074] In an example, the proximal segment 224 of the active wire 200 may also include graphic markings (not shown in Fig. 7) on the outer surface. The markings may be lines, dots, and/or the like, with numbers for measuring length/distance. The markings may assist the operator with assessing the depth that the active wire 200 projects into the myocardial tissue. For example, the operator may compare the alignment of the markings with a reference point to determine a distance that the active wire 200 projects beyond the distal end 142 of the catheter body 140. The reference point may be the proximal end 114 of the catheter 102, or the like.

[0075] The active wire 200 may have fewer or greater than three ring electrodes 218 in other embodiments. In one example, the active wire 200 may only have the tip electrode 212 (e.g., no ring electrodes 218). The number of terminal connector rings 220 may correspond to the total number of electrodes 212, 218 at the distal end 222.

[0076] The active wire 200 can either be straight or have a pre-shaped curvature (J-shaped, serpentine-shaped, multi-dimensional or other pre-forms). The active wire 200 is flexible to navigate a tortuous path through the patient into a chamber of the heart. The wire body 214 may include, for example, stainless steel, nickel-titanium alloy (Nitinol), or the like. The wire body 214 may have a non- conductive surface. For example, the wire body 214 may include an insulative layer that defines the exterior surface of the active wire 200 at locations between the electrodes 212, 218 and the terminal connector rings 220. The insulative layer may be composed of polytetrafluoroethylene (PTFE) or another biocompatible material.

[0077] Additionally or alternatively, the processes described herein may be implemented utilizing all or portions of the structural and/or functional aspects of the methods and systems described in U.S. Patent No. 11 ,529,522, filed August 31 , 2020 and titled “SYSTEMS AND METHODS FOR IMPLANTING A MEDICAL DEVICE USING AN ACTIVE GUIDEWIRE”, the complete subject matter of which is expressly incorporated herein by reference in its entirety.

[0078] The active wire 200 may be communicatively coupled to the pacing system analyzer device 111 shown in Figure 3A. In an example, the proximal end alligator clips or the like) of the pacing system analyzer device 111 via the connector device 230 (shown in Figure 17). Alternatively, the proximal end 224 may be coupled to a transmitter that wirelessly communicates with the pacing system analyzer device 111. The pacing system analyzer device 111 may receive mapping data in the form of electrical signals that are transmitted through the active wire 200.

[0079] In an example, the pacing system analyzer device 111 may electrically map multiple different sites of interest along a region of cardiac tissue using the tip electrode 212. For example, the pacing system analyzer device 111 may include one or more processors (e.g., processing circuitry) and a memory device that stores program instructions directing the processors to perform electrical mapping operations. The one or more processors may control a pulse generator to deliver stimulation energy through the active wire 200 to each SOI. The one or more processors may control sensing circuitry to sense an evoked response at each SOI in response to the stimulation energy that is delivered from the active wire 200. Each SOI may represent at least one of an atrial pacing site, a HIS pacing site, a left bundle branch pacing site, a right bundle branch pacing site, and LV wall pacing site proximate the LV Purkinje fibers.

[0080] Figure 8 shows a distal segment 250 of the lead 202 projecting beyond the distal end 142 of the catheter body 140. The lead 202 can be advanced through the primary lumen 146 to project beyond the distal end 142 for implanting into a SOI that is selected as a target implant location. The distal segment 250 of the lead 202 may include a fixation element 252 for securing the lead 202 to the cardiac tissue (e.g., a septal wall). The fixation element 252 may be a helical coil. The operator may control movement of the lead 202 relative to the catheter body 140 by manipulating an actuator of the delivery system 100 shown in Figure 3A.

[0081] The catheter 102 has two lumens 146, 148 that provide two separate and discrete loading and insertion pathways for the lead 202 and the active wire 200, respectively. As such, the lead 202 may not physically contact the active wire 200. For example, the lead 202 is not advanced over the active wire 200 to surround the active wire 200 as the lead 202 is advanced to couple to the cardiac tissue. The movement of the lead 202 within the catheter 102 and the movement of the active wire 200 within the catheter 102 can each be independently controlled. For example, the active wire 200 may be advanced and retracted relative to the secondary lumen 148 without modifying the position of the lead 202 within the primary lumen 146. This functionality may be useful when investigating different SOI for selecting a target implant location for the lead 202. For example, the active wire 200 can be advanced to project from the distal end 142 for electrically mapping a first SOI and then retracted fully back into the secondary lumen 148 to reposition the distal end segment 124 of the catheter 102 within the patient to approach a second SOI. At the second SOI, the active wire 200 is again advanced as the process repeats. The lead 202 may not project beyond the distal end 142 of the catheter body 140 during this electrical mapping process. The dual lumen catheter 102 is beneficial for preventing contact between the lead 202 and the active wire 200. For example, the active wire 200 does not slide against the lead 202, or vice-versa, when advancing into the myocardial tissue. As a result, there is no risk of damage due to friction or collision/scraping. Furthermore, the lead 202 does not require its own lumen sized to permit the lead 202 to advance over the active wire 200. The lead 202 optionally may not have a lumen.

[0082] In an example, the active wire 200 of the delivery system 100 may not perform similar functions as a traditional guidewire. For example, the active wire 200 may not be used to directly guide the lead 202 to an implant location by allowing the lead 202 to advance over the active wire 200. The active wire 200 may be an active electrode mapping wire that is used to investigate different SOI for determining a long-term implant location of the lead 202.

[0083] In an example, the lead 202 may include a protective sleeve 256 that surrounds the fixation element 252. The protective sleeve 256 may protect the patient tissue from the fixation element 252. The protective sleeve 256 may also protect the fixation element 252 and/or other components of the lead 202 that may be relatively delicate and fragile. The protective sleeve 256 may retract when the lead 202 is implanted into the cardiac tissue at the target implant location. The protective sleeve 256 may be withdrawn after implant with the catheter 102 and the active wire 200.

[0084] Returning to Figure 4, the catheter 102 in an embodiment may include an electrode 260 on the distal end segment 124. The electrode 260 is referred to herein as a catheter electrode 260. Figure 9 illustrates another orientation of the distal end segment 124 of the catheter 102. The catheter electrode 260 is electrically connected to a conductive line 262 that extends along the length of the catheter 102 to the proximal end. The conductive line 262 is housed within the catheter body 140, so it is shown in phantom in Figure 9. The conductive line 262 may be a wire, a metal trace, or the like. The conductive line 262 is used deliver electrical stimulation energy to the electrode 260 and/or convey electrical signals that are sensed by the electrode 260.

[0085] In an embodiment, the catheter electrode 260 is ring-shaped but does not extend around an entire perimeter of the catheter body 140. The catheter electrode 260 extends around the perimeter of the catheter body 140 from a first end 264 of the catheter electrode 260 to a second end 266 of the catheter electrode 260. The first end 264 is separated from the second end 266 to define a gap 268. An outer surface 270 of the catheter body 140 is exposed within the gap 268. In an example, the catheter electrode 260 is positioned so that the gap 268 aligns with a wall segment 272 of the catheter body 140. The wall segment 272 is a portion of the catheter body 140 that has a thinner wall than at least some other portions of the catheter body 140. For example, the primary lumen 146 is located between the secondary lumen 148 and the thin wall segment 272. Stated differently, an edge of the thin wall segment 272 defines a portion of the primary lumen 146 that is approximately 180 degrees from the portion of the primary lumen 146 closest to the secondary lumen 148. Locating the gap 268 of the catheter electrode 260 to align with the thin wall segment 272 provides a cut path for splitting the catheter body 140 after the lead 202 is implanted in the cardiac tissue. The catheter 102 may be split along the cut path to assist with removing the catheter 102 from the lead 202 without dislodging the lead 202.

[0086] The delivery system 100 may use the catheter electrode 260 and the tip electrode 212 as a bipolar electrode pair for testing multiple SOI along the cardiac tissue (e.g., septal wall). The testing is referred to herein as electrical mapping. The delivery system 100 may use the bipolar electrode pair for delivering stimulation energy to the septal wall and/or sensing evoked responses from the septal wall. The bipolar electrode pair may be electrically connected to the pacing system analyzer device 111 for the electrical mapping procedure. The tip electrode 212 may be used as a cathode, and the catheter electrode 260 may be used as an anode, or vice-versa. For some implementations, the SOI may represent a left bundle branch (LBB). The pacing system analyzer device 111 may deliver stimulation energy through the distal end 154 of the active wire 150 to the LBB. By using the electrodes on the catheter 102 and the active wire 200, the lead 202 may not be used during the electrical mapping procedure. For example, the lead 202 may not even be disposed within the primary lumen 146 when the electrical mapping is being performed.

[0087] In an alternative embodiment, the catheter 102 may lack an electrode at the distal end segment. In that case, a bipolar electrode pair for electrical mapping of multiple SOI may be formed by the tip electrode 212 on the active wire 200 and an electrode at the distal end of the lead 202.

[0088] Figure 10 is a perspective view of the distal end segment 124 of the catheter 102 of the delivery system 100 according to a second embodiment. In an example, the catheter 102 includes an annular inflatable balloon 274 secured to the catheter body 140 at the distal end 142 thereof. The annular inflatable balloon 274 (referred to herein as balloon 274) is transformable between a deflated state and an inflated state. The balloon 274 is in the deflated state in Figure 10. In the illustrated embodiment, the balloon 274 is located between the catheter electrode 260 and the distal end 142 of the catheter body 140. The balloon 274 is fluidly connected to a tube that extends along the catheter body 140 towards the proximal end 114 of the catheter 102. A fluid may be injected through the tube into the balloon 274 to transition the balloon 274 from the deflated state to the inflated state.

[0089] Figure 11 is a perspective view of the distal end segment 124 of the catheter 102 shown in Figure 10 with the annular inflatable balloon 274 in the inflated state. When the balloon 274 is inflated, a distal end contact surface 276 of the catheter 102 is enlarged (e.g., has a greater area) relative to when the balloon 274 is deflated. For example, the balloon 274 may significantly radially expand when inflated, without significantly expanding axially along the length of the catheter 102. The inflated balloon 274 may have a relatively flat distal surface 278 that is approximately flush with a distal surface 280 of the catheter body 140. When the balloon 274 is inflated, the distal end contact surface 276 is defined by both the distal surface 280 of the catheter body 140 and the distal surface 278 of the balloon 274.

[0090] Figure 12 is a side view of the distal end segment 124 of the catheter 102 shown in Figures 10 and 11 with the annular inflatable balloon 274 in the inflated state. Enlarging the distal end contact surface 276 may assist with positioning the distal end 116 of the catheter 102 at a normal orientation relative to the surface of the septal wall. The normal orientation may help with securing the lead 202 to the septal wall. Furthermore, the balloon 274 may be at least partially inflated when maneuvering the catheter 102 through the heart of the patient to prevent entanglement. For example, inflating the balloon 274 may enable the catheter 102 to move past fibrotic nests in a chamber of the heart without getting snagged or stuck in small crevasses. In an example, as the catheter 102 is being advanced through the tricuspid valve, the balloon 274 may be partially inflated to a degree to assist in the transition through the tricuspid valve without getting snagged or stuck.

[0091] In an example, the balloon 274 may be inflated by injecting a contrast solution into the balloon 274. The contrast solution may include a contrast element that is designed to be visible in medical images. For example, the contrast element may be visible in X-ray imaging. The contrast solution therefore may enable the physician or other technician to easily view the distal end 116 of the catheter 102 in a medical image even while the distal end 116 is within a chamber of the heart.

[0092] Figure 13 is a perspective view of the distal end segment 124 of the catheter 102 of the delivery system 100 according to a third embodiment. Figure 14 is a side view of the distal end segment 124 of the catheter 102 shown in Figure 13. The catheter 102 in Figure 13 has temporary fixation elements 282 secured to the catheter body 140 and extending beyond the distal end 142 of the catheter body 140. The temporary fixation elements 282 are designed to pierce the cardiac tissue (e.g., the septal wall) at the SOI to stabilize the catheter 102 at the SOI. For example, the temporary fixation elements 282 may aid in prohibiting unintentional catheter movement relative to the septal wall, as such movement could risk dislodging the active wire 200 from the septal wall. The temporary fixation elements 282 may be cleats, tines, sutures, or the like. In the illustrated example, the catheter 102 has four temporary fixation elements 282 circumferentially spaced apart along a perimeter of the catheter 102. The temporary fixation elements 282 may be fixed to a cap 284 that is mounted on the distal end 142 of the catheter body 140. The catheter 102 may include more or less temporary fixation elements 282 in other embodiments, such as one, two, or three temporary fixation elements. The temporary fixation elements 282 may be separate and discrete from the active wire 200 and the lead 202. For example, the temporary fixation elements 282 are spaced apart from the primary lumen 146 and the secondary lumen 148.

[0093] Figure 15A is a side view of the distal end segment 124 of the catheter 102 of the delivery system 100 according to a fourth embodiment. The catheter 102 in Figure 15A has a deflectable sheath 286 at the distal end segment 124. The deflectable sheath 286 is designed to transition between a narrow state and a flared state. The deflectable sheath 286 is in the narrow state in Figure 15A. In the narrow state, the deflectable sheath 286 surrounds a portion of the catheter body and projects beyond the distal end of the catheter body.

[0094] Figure 15B is a side view of the distal end segment 124 of the catheter 102 of Figure 15A with the deflectable sheath 286 in the flared state. In the flared state, the deflectable sheath 286 defines a radially-extending flange 288 that enlarges the distal end contact surface 276 of the catheter 102. Figure 16 is a perspective view of the distal end segment 124 of the catheter 102 of Figures 15A and 15B with the deflectable sheath 286 in the flared state. The radially-extending flange 288 aids in positioning the catheter 102 at a normal orientation relative to the septal wall. The deflectable sheath 286 may be designed to transition from the narrow state to the flared state when the distal end segment 124 is pressed against the septal wall at the SOI. For example, the deflectable sheath 286 may fold back, deflect, collapse, split, or the like, to transition from the narrow state to the flared state.

[0095] Although Figures 10 through 16 are described as three different alternative embodiments of the catheter 102, the features of the different embodiments may be combined. For example, the catheter 102 may include both the temporary fixation elements 282 shown in Figures 13 and 14 and the annular inflatable balloon 274 shown in Figures 10 through 12.

[0096] Figure 17 illustrates the connector device 230 of the delivery system 100 coupled to the active wire 200 according to an embodiment. The connector device 230 may assist the physician or other technician with communicatively connecting the active lead 200 to the pacing system analyzer 111 or another benchtop pacing system. The connector device 230 is removably coupled to the active wire 200. [0097] In an example, the connector device 230 has a hub segment 232 and a contact segment 234. The contact segment 234 may extend from the hub segment 232. The connector device 230 may have a one-piece (e.g., monolithic, unitary, etc.) connector body 236. The connector body 236 may extend along both the hub segment 232 and the contact segment 234. The hub segment 232 and the contact segment 234 may define a cavity 238 (shown in Figure 19). The cavity 238 is open at a distal end 240 of the hub segment 232, opposite the contact segment 234. The cavity 238 continuously extends from the distal end 240 through the hub segment 232 and into the contact segment 234. The cavity 238 may linearly extend along a central axis 242 (shown in Figure 19). The active wire 200 may be coupled to the connector device 230 by inserting the proximal segment 224 (shown in Figure 7) into the cavity 238 through the opening at the distal end 240 of the hub segment 232. The active wire 200 may be advanced relative to the connector device 230 until the active wire 200 achieves a fully loaded position. The active wire 200 is in the fully loaded position in Figure 17. In the fully loaded position, the proximal segment 224 of the active wire 200 aligns with the contact segment 234 of the connector device 230 so that the terminal connector rings 220 are disposed within the contact segment 234.

[0098] The contact segment 234 of the connector device 230 may define multiple windows 244 that are open to the cavity 238. For example, each window 244 extends through a wall of the connector body 236 from the cavity 238 to an exterior surface 246 of the connector body 236. The windows 244 are shown more clearly in Figure 18 than in Figure 17. The windows 244 are numbered, sized, and positioned to align with the terminal connector rings 220 of the active wire 200. For example, when the active wire 200 is fully loaded into the connector device 230, each of the terminal connector rings 220 may align with a different one of the windows 244. The terminal connector rings 220 may be exposed through the windows 244 for establishing an electrically conductive connection with clip connectors of the pacing system analyzer 111. [0099] In an example, the connector device 230 includes spring clips 248 mounted on the contact segment 234. For example, the spring clips 248 may be secured to the connector body 236 and positioned along the exterior surface 246 of the connector body 236. The spring clips 248 may align with the windows 244. The spring clips 248 may make physical contact with the terminal connector rings 220 of the active wire 200 through the windows 244. For example, when one or more clip connectors of the pacing system analyzer 111 are coupled to the connector device 230, the clip connector(s) may press the spring clips 248 downward into the windows 244 to make and/or maintain physical contact with the terminal connector rings 220. In an example, the contact segment 234 of the connector device 230 includes multiple discrete grooves or tracks 249 along the exterior surface 246. The grooves 249 are recessed from the portions of the exterior surface 246 surrounding and between the grooves 249. The grooves 249 may be sized to each accommodate one spring clip 248, or one pair of spring clips 248 that extend in opposite directions from the window 244. The grooves 249 may restrict lateral movement of the spring clips 248 relative to the connector device 230. The spring clips 248 may be optional.

[0100] Figure 18 shows the connector device 230 of Figure 17 without the spring clips 248. In an alternative embodiment, the connector device 230 may not include spring clips. For example, one or more clip connectors of the pacing system analyzer 111 may couple to the contact segment 234 and extend through the windows 244 to directly contact the terminal connector rings 220.

[0101] Figure 19 is a cross-sectional view showing the active wire 200 within the hub segment 232 of the connector device 230 according to an embodiment. The cross-section is taken along line 19-19 in Figure 18. In an example, the connector device 230 may include an O-ring 290 within the hub segment 232. The O-ring 290 may surround the cavity 238 and project at least partially into the cavity 238 to provide a restriction. For example, when the active wire 200 is loaded into the cavity 238, the O-ring 290 may engage (e.g., grip) the active wire 200 via an interference fit. The O-ring 290 may increase the force required to pull the active wire 200 out of the cavity 238, which reduces the risk of unintentional uncoupling of the connector device 230 and active wire 200. The O-ring 290 may be held within an annular slot 292 or groove defined along an interior surface 294 of the hub segment 232 defining the cavity 238. Figure 20 is an elevation view showing the distal end 240 of the connector device 230 of Figure 19. A portion of the O-ring 290 is visible within the cavity 238 defined by the hub segment 232.

[0102] Figure 21 illustrates the connector device 230 according to an embodiment that includes a rotatable locking mechanism 296. The rotatable locking mechanism 296 may be used in addition to the O-ring 290 shown in Figures 19 and 20 or as an alternative to the O-ring 290. The rotatable locking mechanism

296 may include a dial 297 on the hub segment 232 that is rotatable relative to the connector body 236. The dial 297 may be operably connected (e.g., mechanically coupled) to teeth 298. The teeth 298 may be held within an annular wall 299 of the hub segment 232. The dial 297 may be connected to the teeth 298 through the annular wall 299. The teeth 298 may be radially movable in a first direction into the cavity 238 towards the central axis 242 (shown in Figure 19) and a second, opposite direction away from the central axis 242. For example, rotation of the dial

297 in a first direction (e.g., clockwise) may cause the teeth 298 to move radially inward (towards the central axis 242) to grip the active wire 200 in a closed configuration of the locking mechanism 296. Rotation of the dial 297 in a second, opposite direction (e.g., counterclockwise) may cause the teeth 298 to retract radially outward (away from the central axis 242) to release the grip on the active wire 200 in an open configuration of the locking mechanism 296. The active wire 200 can be loaded into or removed from the cavity 238 when the locking mechanism 296 is in the open configuration.

[0103] Figure 22 is a flowchart of a method 300 of delivering an IMD or a portion of an IMD to cardiac tissue within a patient according to an embodiment. The method 300 may use the delivery system 100 including the catheter 102 and active wire 200 as shown and described in Figures 1 through 21. In different embodiments, the method may include different steps not shown in Figure 22, may omit one or more of the steps shown in Figure 22, and/or may have a different order of the steps than shown in Figure 22.

[0104] At step 302, a catheter 102 is loaded into a chamber of a heart and positioned proximate to myocardial tissue at a first SOI. The first SOI represents a candidate implant location for delivering pacing therapy. The first SOI may be a right ventricle apex or the ventricular septal wall for left bundle branch area pacing (LBBAP). Figure 23 illustrates the distal end segment 124 of the catheter 102 within a heart chamber and pressed against a septal wall 400 at a first SOI. The catheter 102 includes a catheter body 140 that defines a primary lumen 146 and a secondary lumen 148 therethrough. The primary and secondary lumens 146, 148 are spaced apart. The primary lumen 146 has a greater cross-sectional size than the secondary lumen 148.

[0105] At step 304, an active wire 200 (“AW” in Figure 22) is advanced through the secondary lumen 148 of the catheter body 140 so that a distal end 210 of the active wire 200 pierces the septal wall 400 at the first SOI. The distal segment 222 of the active wire 200 has a tip electrode 212 and may include one or more ring electrodes 218. Figure 24 illustrates the distal end segment 124 of the catheter 102 with the active wire 200 projecting beyond the catheter body 140 into the septal wall 400 at the first SOI. The distal segment 222 of the active wire 200 may be inserted through the myocardial tissue to a depth that is selected by the physician or other technician controlling the delivery system 100. The depth may be selected based on a desired therapy site. For example, the first SOI may be located at a different depth into the myocardial tissue than a second SOI.

[0106] The active wire 200 may be electrically connected to a pacing system analyzer device 111 via a connector device 230. The connector device 230 may be coupled to the proximal end 216 of the active wire 200. The active wire 200 may include one or more terminal connector rings 220 along a proximal segment 224 that align with corresponding windows 244 defined through a contact segment 234 of the connector device 230 when the active wire 200 is fully loaded within a cavity 238 of the connector device 230. The pacing system analyzer device 111 may be electrically connected to the contact segment 234 of the connector device 234 by applying one or more clip connectors to the contact segment 234. The clip connectors may be alligator clips or the like that connect cables or wires of the pacing system analyzer device 111 to the terminal connector rings 220 of the active wire 200.

[0107] At step 306, the first SOI is electrically mapped by delivering stimulation energy (e.g., a pacing pulse) from the pacing system analyzer device 111 to the septal wall 400, using the active wire 200, and sensing an evoked response in the septal wall 400 to the stimulation energy. The tip electrode 212 of the active wire 200 is used to electrically map the first SOI. For example, the tip electrode 212 may be used as a cathode. In an embodiment, the tip electrode 212 forms a bipolar electrode pair with a catheter electrode 260 at the distal end segment 124 of the catheter 102. Optionally, the one or more ring electrodes 218 may be used to deliver the pacing pulse and/or sense the evoked response to the pacing pulse. The pacing system analyzer device 111 may provide output indicating a level or extent of capture achieved by the pacing pulse. The physician or other technician may analyze the output generated by the pacing system analyzer device 111.

[0108] The physician may adjust the position of the active wire 200 based on the output to determine (e.g., through trial and error) a long-term implant location for the lead 202. For example, depending on the number of electrode pathways and/or physician requirements, the active wire 200 may provide multiple unipolar pacing vectors and/or multiple bipolar pacing vectors within a single SOI within the septal wall. This functionality may reduce the number of unnecessary reattempts due to suboptimal electrode locations within an otherwise acceptable site. [0109] At step 308, it is determined whether another SOI should be mapped (e.g., investigated) as a possible implant location. The determination may be made by the physician or other technician that controls the delivery system 100. If the answer is yes, then the active wire 200 is repositioned at step 310. Step 310 repositions the active wire 210 so the distal end 210 thereof is at another SOI (e.g., a second SOI) along the septal wall 400. The second SOI may be at a different longitudinal and/or lateral location of the septal wall 400 and/or a different depth into the septal wall 400, relative to the first SOI. The flow of the method then returns to step 306 and the mapping procedure is performed for the second SOI. This sequence of steps may be repeated to electrically map multiple different SOI along the septal wall 400. Once the answer at step 308 is “no,” meaning there are no more SOIs to electrically map, then flow proceeds to step 312.

[0110] At step 312, one of the SOI is selected as a target implant location by comparing the electrical mapping of the SOI. For example, a pacing system analyzer device 111 may analyze the evoked responses to the stimulation energy at each of the SOI that are electrically mapped. The pacing system analyzer device 111 may select the SOI that has the greatest amplitude of evoked responses as the target implant location. Optionally, the physician or other technician that is controlling the delivery system may select which SOI is the target implant location by analyzing the electrical mapping results.

[0111] After selecting the target implant location, a lead 202 is advanced at step 314 through a primary lumen 146 of the catheter 102 so a distal segment 250 of the lead 202 secures to the septal wall 400 at the target implant location. This step may first involve repositioning the catheter 102 within the patient so that the distal end 116 thereof is next to, and optionally abuts against, a location of the septal wall 400 that aligns with the target implant location. Figure 25 illustrates the distal end segment 124 of the catheter 102 positioned proximate to a second SOI that is selected as the target implant location. [0112] Optionally, the method may involve using the active wire 200 as a guidewire for guiding the movement of the lead 202 towards the target implant location. In this example, the active wire 200 may be advanced through the secondary lumen 148 so the distal end 210 pierces the septal wall 400, prior to advancing the lead 202 to pierce the septal wall 400. Figure 25 shows the active wire 200 projecting into the septal wall 400. The implanted active wire 200 may assist with securing the catheter 102 to the septal wall 400 at the target implant location. For example, the active wire 200 may function as a tether that secures the catheter 102 in position at the septal wall 400, reducing the risk of the catheter 102 moving away from the target implant location prior to implantation of the IMD or the lead 202 thereof.

[0113] Step 314 refers to the lead 202 of the IMD advancing through the primary lumen 146, but the method can be performed to secure an IMD itself to the septal wall 400. For example, the method can be used to deliver a leadless pacemaker, cardiac monitoring device, or the like, through the primary lumen 146 instead of the lead 202. When the active wire 200 is used as a guidewire, the distal segment 250 of the lead 202 pierces the septal wall 400 next to the active wire 200. Figure 25 shows the distal segment 250 of the lead 202 advanced into the septal wall 400 at the target implant location. In this example, the lead 202 does not penetrate the septal wall 400 at all until after the target implant location is determined. For example, if the first SOI is not selected as the target implant location, then the lead 202 does not penetrate the septal wall 400 at the first SOI.

[0114] At step 316, the catheter 102 and the active wire 200 are withdrawn from the patient while the lead 202 remains secured at the target implant location. When the active wire 200 is used as the guidewire, the first action may be to retract or withdraw the active wire 200 into the secondary lumen 148 of the catheter 102. Then, the catheter 102 can be withdrawn with the active wire 200 therein. Optionally, withdrawing the catheter 102 may include splitting the catheter 102 along a length of the catheter 102 at a thin wall segment 272 of the catheter body 140. The lead 202 is retained within the patient at the target implant site for delivering and/or sensing electrical signals.

[0115] Figure 26 illustrates a block diagram of an exemplary IMD 600 that is configured to be implanted into the patient in accordance with embodiments herein. The IMD 600 may treat both fast and slow arrhythmias with stimulation therapy, including cardioversion, pacing stimulation, an implantable cardioverter defibrillator, suspend tachycardia detection, tachyarrhythmia therapy, and/or the like.

[0116] The IMD 600 has a housing 661 to hold the electronic/computing components. The housing 661 (which is often referred to as the “can,” “case,” “encasing,” or “case electrode”) may be programmably selected to act as the return electrode for certain stimulus modes. The housing 661 further includes a connector (not shown) with a plurality of terminals 601 , 602, 604, 606, 608, and 610. The terminals may be connected to one or more leads that are located in various locations within and about the heart. Each lead may have one or more electrodes. The type and location of each electrode may vary. For example, the electrodes may include various combinations of ring, tip, coil, shocking electrodes, and the like.

[0117] The IMD 600 includes a programmable microcontroller 620 that controls various operations of the IMD 600, including cardiac monitoring and stimulation therapy. The microcontroller 620 includes a microprocessor (or equivalent control circuitry), one or more processors, RAM and/or ROM memory, logic and timing circuitry, state machine circuitry, and I/O circuitry. The IMD 600 further includes a pulse generator 622 that generates stimulation pulses, based on input electrical signals 624, for connecting the desired electrodes to the appropriate I/O circuits, thereby facilitating electrode programmability. The microcontroller 620 controls an electrode configuration switch 626 via control signals 628. The electrode configuration switch 626 is electrically connected to the terminals 601 , 602, 604, 606, 608, and 610. [0118] Optionally, the IMD 600 may include multiple pulse generators, similar to the pulse generator 622, where each pulse generator is coupled to one or more leads/electrodes and controlled by the microcontroller 620 to deliver select stimulus pulse(s) to the corresponding one or more electrodes. The IMD 600 includes sensing circuit 644 selectively coupled to one or more electrodes that perform sensing operations, through the switch 626 to detect the presence of cardiac activity in the chamber of the heart. The output of the sensing circuit 644 is connected to the microcontroller 620 which, in turn, triggers, or inhibits the pulse generator 622 in response to the absence or presence of cardiac activity. The sensing circuit 644 receives a control signal 646 from the microcontroller 620 for purposes of controlling the gain, threshold, polarization charge removal circuitry (not shown), and the timing of any blocking circuitry (not shown) coupled to the inputs of the sensing circuit 644.

[0119] In the example of Figure 26, the sensing circuit 644 is illustrated. Optionally, the IMD 600 may include multiple sensing circuits 644, where each sensing circuit is coupled to one or more leads/electrodes and controlled by the microcontroller 620 to sense electrical activity detected at the corresponding one or more electrodes. The sensing circuit 644 may operate in, for example, a unipolar sensing configuration or a bipolar sensing configuration.

[0120] The IMD 600 further includes an analog-to-digital (A/D) data acquisition system (DAS) 650 coupled to one or more electrodes via the switch 626 to sample cardiac signals across any pair of desired electrodes. The A/D converter 650 is configured to acquire intracardiac electrogram signals, convert the raw analog data into digital data and store the digital data for later processing and/or telemetric transmission to an external device 690 (e g., a programmer, local transceiver, or a diagnostic system analyzer). The A/D converter 650 is controlled by a control signal 656 from the microcontroller 620.

[0121] The microcontroller 620 is operably coupled to a memory 660 by a suitable data/address bus 662. The programmable operating parameters used by the microcontroller 620 are stored in the memory 660 and used to customize the operation of the IMD 600 to suit the needs of a particular patient. The operating parameters of the IMD 600 may be non-invasively programmed into the memory 660 through a telemetry circuit 664 in telemetric communication via communication link 667 (e.g., MICS, Bluetooth low energy, and/or the like) with the external device 690.

[0122] The IMD 600 can optionally include one or more physiological sensors 670. Such sensors are commonly referred to as “rate-responsive” sensors because they are typically used to adjust pacing stimulation rates according to the exercise state of the patient. However, the physiological sensor 670 may further be used to detect changes in cardiac output, changes in the physiological condition of the heart, or diurnal changes in activity (e.g., detecting sleep and wake states). Signals generated by the physiological sensors 670 are passed to the microcontroller 620 for analysis. While shown as being included within the IMD 600, the physiological sensor(s) 670 may be external to the IMD 600, yet still, be implanted within or carried by the patient. Examples of physiological sensors might include sensors that, for example, sense respiration rate, pH of blood, ventricular gradient, activity, position/posture, minute ventilation, and/or the like.

[0123] A battery 672 provides operating power to all of the components in the IMD 600. The battery 672 is capable of operating at low current drains for long periods of time, and is capable of providing a high-current pulses (for capacitor charging) when the patient requires a shock pulse (e.g., in excess of 2 A, at voltages above 2 V, for periods of 10 seconds or more). The battery 672 also desirably has a predictable discharge characteristic so that elective replacement time can be detected. As one example, the IMD 600 employs lithium/silver vanadium oxide batteries.

[0124] The IMD 600 optionally includes an impedance measuring circuit 674, which can be used for many things, including sensing respiration phase. The impedance measuring circuit 674 is coupled to the switch 626 so that any desired electrode and/or terminal may be used to measure impedance in connection with monitoring respiration phase. The IMD 600 is further equipped with a communication modem (modulator/demodulator) 640 to enable wireless communication with other devices, implanted devices and/or external devices. In one implementation, the communication modem 640 may use high frequency modulation of a signal transmitted between a pair of electrodes. As one example, the signals may be transmitted in a high frequency range of approximately 10-80 kHz, as such signals travel through the body tissue and fluids without stimulating the heart or being felt by the patient.

[0125] Optionally, the microcontroller 620 may control a shocking circuit 680 by way of a timing control 632. The shocking circuit 680 generates shocking pulses as controlled by the microcontroller 620. The shocking circuit 680 may be controlled by the microcontroller 620 by a control signal 682.

[0126] Although not shown, the microcontroller 620 may further include other dedicated circuitry and/or firmware/software components that assist in monitoring various conditions of the patient's heart and managing pacing therapies. The microcontroller 620 optionally includes a timing control 632, an arrhythmia detector 634, a morphology detector 636 and multi-phase therapy controller 633. The timing control 632 is used to control various timing parameters, such as stimulation pulses (e.g., pacing rate, atria-ventricular (AV) delay, atrial interconduction (A-A) delay, ventricular interconduction (V-V) delay, etc.) as well as to keep track of the timing of RR-intervals, refractory periods, blanking intervals, noise detection windows, evoked response windows, alert intervals, marker channel timing, and the like.

[0127] The morphology detector 636 is configured to review and analyze one or more features of the morphology of cardiac activity signals. For example, in accordance with embodiments herein, the morphology detector 636 may analyze the morphology of detected R waves, where such morphology is then utilized to determine whether to include or exclude one or more beats from further analysis. For example, the morphology detector 636 may be utilized to identify nonconducted ventricular events, such as ventricular fibrillation and the like.

[0128] The arrhythmia detector 634 may be configured to apply one or more arrhythmia detection algorithms for detecting arrhythmia conditions. By way of example, the arrhythmia detector 634 may apply various detection algorithms. The arrhythmia detector 634 may be configured to declare a ventricular fibrillation episode based on the cardiac events.

[0129] The therapy controller 633 is configured to perform the operations described herein. The therapy controller 633 is configured to identify a multi-phase therapy based on the ventricular fibrillation episode, the multi-phase therapy including a pacing therapy. The therapy controller 633 is configured to manage delivery of the burst pacing therapy at a pacing site in a coordinated manner after the one or more shocks. The pacing site may be located at a target SOI, such as a His Bundle. Optionally, other pacing sites may be located at one of a left ventricular (LV) site or a right ventricular (RV) site. The therapy controller 633 may configured to manage delivery of the shock along a shocking vector between shocking electrodes.

[0130] Further, the disclosure comprises examples according to the following embodiments.

An embodiment of the invention relates to a delivery system, comprising a catheter including a catheter body that has a distal end configured to be located within a chamber of a heart proximate to myocardial tissue at a site of interest (SOI), the catheter body defining a primary lumen and a secondary lumen therethrough, the primary and secondary lumens spaced apart from each other, the primary lumen having a greater cross-sectional size than the secondary lumen and configured to receive at least a portion of an implantable medical device (IMD) therein and to permit the portion of the IMD to move relative to the catheter. The delivery system also comprises an active wire configured to extend through the secondary lumen of the catheter body, the active wire including a tip electrode at a distal end of the active wire, the active wire configured to be moved through the secondary lumen so that the distal end of the active wire projects beyond the distal end of the catheter body to pierce the myocardial tissue at the SOI.

[0131] In an embodiment, an intervening wall of the catheter body separates the primary lumen from the secondary lumen along the length of the catheter body between the proximal and distal ends of the catheter body.

[0132] In an embodiment, the catheter includes an electrode on a distal end segment of the catheter.

[0133] In an embodiment, the electrode on the distal end segment of the catheter extends around a perimeter of the catheter body from a first end of the electrode to a second end of the electrode, the first end separated from the second end to define a gap along which an outer surface of the catheter body is exposed.

[0134] In an embodiment, the gap defined between the first and second ends of the electrode aligns with a thin wall segment of the catheter body. In this embodiment, the primary lumen is between the secondary lumen and the thin wall segment.

[0135] In an embodiment, the tip electrode of the active wire and the electrode of the catheter define a bipolar electrode pair for at least one of delivering stimulation energy to the myocardial tissue or sensing evoked responses from the myocardial tissue in response to the stimulation energy being delivered to the myocardial tissue.

[0136] In an embodiment, the catheter further comprises an annular inflatable balloon secured to the catheter body at the distal end of the catheter body. In this embodiment, the annular inflatable balloon configured to be inflated to enlarge a distal end contact surface of the catheter.

[0137] In an embodiment, the catheter further comprises one or more temporary fixation elements secured to the catheter body and extending beyond the distal end of the catheter body. In this embodiment, the one or more temporary fixation elements spaced apart from the first and second lumens, discrete from the active wire and the IMD, and configured to pierce the myocardial tissue at the SOI.

[0138] In an embodiment, the catheter further comprises a deflectable sheath at a distal end segment of the catheter. In this embodiment, the deflectable sheath configured to transition from a narrow state to a flared state when the distal end segment is pressed against the myocardial tissue at the SOI, the deflectable sheath in the flared state defining a radially-extending flange that enlarges a distal end contact surface of the catheter.

[0139] In an embodiment, the primary lumen is configured to receive a lead of the IMD as the portion of the IMD.

[0140] In an embodiment, the active wire includes the tip electrode and one or more ring electrodes along a distal segment of the active wire. In this embodiment, the tip electrode and the one or more ring electrodes spaced apart from one another along a length of the active wire.

[0141] In an embodiment, the active wire includes multiple terminal connector rings along a proximal segment of the active wire. In this embodiment, each of the terminal connector rings electrically connected to a different one of the tip electrode and the one or more ring electrodes.

[0142] In an embodiment, the delivery system further comprising a connector device removably coupled to the proximal segment of the active wire. In this embodiment, the connector device comprising a hub segment and a contact segment extending from the hub segment. The hub segment and the contact segment continuously defining a cavity configured to receive the active wire therein. The contact segment defining multiple windows that are open to the cavity. In this embodiment, the windows are configured to align with the terminal connector rings of the active wire when the active wire is fully loaded within the cavity. [0143] In an embodiment, the connector device includes spring clips mounted on the contact segment. In this embodiment, the spring clips aligning with the windows and configured to contact the terminal connector rings through the windows when one or more clip connectors of a pacing system analyzer are coupled to the connector device.

[0144] In an embodiment, the connector device includes an O-ring within the hub segment and surrounding the cavity, the O-ring configured to grip the active wire via an interference fit.

[0145] In an embodiment, the connector device includes a dial on the hub segment that is rotatable relative to a body of the connector device. In this embodiment, the dial operably connected to teeth configured to radially move towards a central axis of the cavity based on rotation of the dial to grip the active wire.

Another embodiment of the invention relates to a method comprising loading a catheter into a chamber of a heart proximate to myocardial tissue at a first site of interest (SOI), the catheter including a catheter body that defines a primary lumen and a secondary lumen therethrough, the primary and secondary lumens spaced apart from each other, the primary lumen having a greater cross- sectional size than the secondary lumen and configured to receive at least a portion of an implantable medical device (IMD) therein and to permit the portion of the IMD to move relative to the catheter. The method also comprises advancing an active wire through the secondary lumen of the catheter body so that a distal segment of the active wire pierces the myocardial tissue at the first SOI, the distal segment of the active wire including a tip electrode. The method further comprises advancing at least a portion of an implantable medical device (IMD) through the primary lumen of the catheter body so that a distal end of the portion of the IMD secures to the myocardial tissue next to the distal segment of the active wire. The method additionally comprises retracting the active wire into the secondary lumen so that the distal segment exits the myocardial tissue. The method also comprises withdrawing the catheter and the active wire from the chamber of the heart while the portion of the IMD remains secured to the myocardial tissue.

In an embodiment, the method further comprising electrically mapping the first SOI by delivering stimulation energy from a pacing system analyzer to the myocardial tissue at the first SOI via at least one of the tip electrode or a second electrode and sensing an evoked response within the myocardial tissue in response to the stimulation energy. In this embodiment, the portion of the IMD is advanced through the primary lumen of the catheter body in response to determining, based on the electrical mapping, that the first SOI is a target implant location.

[0146] In an embodiment, the second electrode is a catheter electrode disposed on the catheter. In this embodiment, the tip electrode and the catheter electrode form a bipolar electrode pair for at least one of delivering the stimulation energy or sensing the evoked response.

In an embodiment, the method further comprising repositioning the catheter within the chamber after electrically mapping the first SOI so that a distal end segment of the catheter is positioned proximate to the myocardial tissue at a second SOI. The method also comprises, in this embodiment, electrically mapping the second SOI, and determining that the first SOI is the target implant location instead of the second SOI based on a comparison of the electrical mapping of the second SOI with the electrical mapping of the first SOI.

[0147] In an embodiment, withdrawing the catheter from the chamber of the heart comprises splitting the catheter along a length of the catheter at a wall segment of the catheter body. In this embodiment, the primary lumen is between the secondary lumen and the wall segment.

In an embodiment, the method further comprising inflating an annular inflatable balloon that is at a distal end segment of the catheter, wherein inflating the annular inflatable balloon enlarges a distal end contact surface of the catheter. [0148] In an embodiment, the method further comprising coupling the active wire to a connector device configured to electrically connect to clip connectors of a pacing system analyzer. In this embodiment, a proximal segment of the active wire includes multiple terminal connector rings, and the connector device defines a cavity and multiple windows that are open to the cavity. In this embodiment, coupling the active wire to the connector device comprises loading the proximal segment of the active wire into the cavity until the terminal connector rings align with the windows.

A further embodiment of the invention relates to a delivery system comprising a catheter comprising a catheter body that has a distal end configured to be located within a chamber of a heart proximate to myocardial tissue at a site of interest (SOI), the catheter body defining a primary lumen and a secondary lumen therethrough, the primary and secondary lumens spaced apart from each other, the primary lumen having a greater cross-sectional size than the secondary lumen, wherein the primary lumen is configured to receive a lead therein and to permit the lead to move relative to the catheter. The catheter also comprises a catheter electrode located at or proximate to the distal end of the catheter body. The delivery system also comprises an active wire within the secondary lumen of the catheter body, the active wire including a tip electrode at a distal end of the active wire, the active wire configured to be moved relative to the catheter to advance a distal segment of the active wire beyond the distal end of the catheter body to pierce the myocardial tissue at the SOI.

[0149] Reference throughout this specification to “one embodiment” or “an embodiment” (or the like) means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” or the like in various places throughout this specification are not necessarily all referring to the same embodiment. [0150] The term “sized” as used herein is not limited to the act of manufacturing, but rather refers to a dimension similar to length, width, volume, etc. A lumen being sized to accommodate a specific component is not a method operation, but rather a characteristic of the lumen.

[0151] It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the inventive subject matter without departing from its scope. While the dimensions and types of materials described herein are intended to define the parameters of the inventive subject matter, they are by no means limiting and are exemplary embodiments. Many other embodiments will be apparent to one of ordinary skill in the art upon reviewing the above description. The scope of the inventive subject matter should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. § 112(f) unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.

Claims

WHAT IS CLAIMED IS:

1 . A delivery system, comprising: a catheter including a catheter body that has a distal end configured to be located within a chamber of a heart proximate to myocardial tissue at a site of interest (SOI), the catheter body defining a primary lumen and a secondary lumen therethrough, the primary and secondary lumens spaced apart from each other, the primary lumen having a greater cross-sectional size than the secondary lumen and configured to receive at least a portion of an implantable medical device (IMD) therein and to permit the portion of the IMD to move relative to the catheter; and an active wire configured to extend through the secondary lumen of the catheter body, the active wire including a tip electrode at a distal end of the active wire, the active wire configured to be moved through the secondary lumen so that the distal end of the active wire projects beyond the distal end of the catheter body to pierce the myocardial tissue at the SOI.

2. The delivery system of claim 1 , wherein an intervening wall of the catheter body separates the primary lumen from the secondary lumen along the length of the catheter body between a proximal end and the distal end of the catheter body.

3. The delivery system of claim 1 , wherein the catheter includes an electrode on a distal end segment of the catheter.

4. The delivery system of claim 3, wherein the electrode on the distal end segment of the catheter extends around a perimeter of the catheter body from a first end of the electrode to a second end of the electrode, the first end separated from the second end to define a gap along which an outer surface of the catheter body is exposed.

5. The delivery system of claim 4, wherein the gap defined between the first and second ends of the electrode aligns with a wall segment of the catheter body, wherein the primary lumen is between the secondary lumen and the wall segment.

6. The delivery system of claim 3, wherein the tip electrode of the active wire and the electrode of the catheter are electrically connected to a pulse generator and sensing circuit, wherein the tip electrode and the electrode of the catheter define a bipolar electrode pair for at least one of delivering stimulation energy from the pulse generator to the myocardial tissue or sensing evoked responses from the myocardial tissue in response to the stimulation energy being delivered to the myocardial tissue.

7. The delivery system of claim 1 , wherein the catheter further comprises an annular inflatable balloon secured to the catheter body at the distal end of the catheter body, the annular inflatable balloon configured to be inflated to enlarge a distal end contact surface of the catheter.

8. The delivery system of claim 1 , wherein the catheter further comprises one or more temporary fixation elements secured to the catheter body and extending beyond the distal end of the catheter body, the one or more temporary fixation elements spaced apart from the first and second lumens, discrete from the active wire and the IMD, and configured to pierce the myocardial tissue at the SOI.

9. The delivery system of claim 1 , wherein the catheter further comprises a deflectable sheath at a distal end segment of the catheter, the deflectable sheath configured to transition from a narrow state to a flared state when the distal end segment is pressed against the myocardial tissue at the SOI, the deflectable sheath in the flared state defining a radially-extending flange that enlarges a distal end contact surface of the catheter.

10. The delivery system of claim 1 , wherein the primary lumen is configured to receive a lead of the IMD as the portion of the IMD.

11 . The delivery system of claim 1 , wherein the active wire includes the tip electrode and one or more ring electrodes along a distal segment of the active wire, the tip electrode and the one or more ring electrodes spaced apart from one another along a length of the active wire.

12. The delivery system of claim 11 , wherein the active wire includes multiple terminal connector rings along a proximal segment of the active wire, each of the terminal connector rings electrically connected to a different one of the tip electrode and the one or more ring electrodes.

13. The delivery system of claim 12, further comprising a connector device removably coupled to the proximal segment of the active wire, the connector device comprising a hub segment and a contact segment extending from the hub segment, the hub segment and the contact segment continuously defining a cavity configured to receive the active wire therein, the contact segment defining multiple windows that are open to the cavity, wherein the windows are configured to align with the terminal connector rings of the active wire when the active wire is fully loaded within the cavity.

14. The delivery system of claim 13, wherein the connector device includes spring clips mounted on the contact segment, the spring clips aligning with the windows and configured to contact the terminal connector rings through the windows when one or more clip connectors of a pacing system analyzer are coupled to the connector device.

15. The delivery system of claim 13, wherein the connector device includes an O-ring within the hub segment and surrounding the cavity, the O-ring configured to grip the active wire via an interference fit.

16. The delivery system of claim 13, wherein the connector device includes a dial on the hub segment that is rotatable relative to a body of the connector device, the dial operably connected to teeth configured to radially move towards a central axis of the cavity based on rotation of the dial to grip the active wire.

17. A method comprising: loading a catheter into a chamber of a heart proximate to myocardial tissue at a first site of interest (SOI), the catheter including a catheter body that defines a primary lumen and a secondary lumen therethrough, the primary and secondary lumens spaced apart from each other, the primary lumen having a greater cross- sectional size than the secondary lumen and configured to receive at least a portion of an implantable medical device (IMD) therein and to permit the portion of the IMD to move relative to the catheter; advancing an active wire through the secondary lumen of the catheter body so that a distal segment of the active wire pierces the myocardial tissue at the first SOI, the distal segment of the active wire including a tip electrode; advancing at least a portion of an implantable medical device (IMD) through the primary lumen of the catheter body so that a distal end of the portion of the IMD secures to the myocardial tissue next to the distal segment of the active wire; retracting the active wire into the secondary lumen so that the distal segment exits the myocardial tissue; and withdrawing the catheter and the active wire from the chamber of the heart while the portion of the IMD remains secured to the myocardial tissue.

18. The method of claim 17, further comprising: electrically mapping the first SOI by delivering stimulation energy from a pacing system analyzer to the myocardial tissue at the first SOI via at least one of the tip electrode or a second electrode and sensing an evoked response within the myocardial tissue in response to the stimulation energy, wherein the portion of the IMD is advanced through the primary lumen of the catheter body in response to determining, based on the electrical mapping, that the first SOI is a target implant location.

19. The method of claim 18, wherein the second electrode is a catheter electrode disposed on the catheter, wherein the tip electrode and the catheter electrode form a bipolar electrode pair for at least one of delivering the stimulation energy or sensing the evoked response.

20. The method of claim 18, further comprising: repositioning the catheter within the chamber after electrically mapping the first SOI so that a distal end segment of the catheter is positioned proximate to the myocardial tissue at a second SOI; electrically mapping the second SOI; and determining that the first SOI is the target implant location instead of the second SOI based on a comparison of the electrical mapping of the second SOI with the electrical mapping of the first SOI.

21 . The method of claim 17, wherein withdrawing the catheter from the chamber of the heart comprises splitting the catheter along a length of the catheter at a wall segment of the catheter body, wherein the primary lumen is between the secondary lumen and the wall segment.

22. The method of claim 17, further comprising: inflating an annular inflatable balloon that is at a distal end segment of the catheter, wherein inflating the annular inflatable balloon enlarges a distal end contact surface of the catheter.

23. The method of claim 17, further comprising coupling the active wire to a connector device configured to electrically connect to clip connectors of a pacing system analyzer, wherein a proximal segment of the active wire includes multiple terminal connector rings, and the connector device defines a cavity and multiple windows that are open to the cavity, wherein coupling the active wire to the connector device comprises loading the proximal segment of the active wire into the cavity until the terminal connector rings align with the windows.

24. A delivery system comprising: a catheter comprising: a catheter body that has a distal end configured to be located within a chamber of a heart proximate to myocardial tissue at a site of interest (SOI), the catheter body defining a primary lumen and a secondary lumen therethrough, the primary and secondary lumens spaced apart from each other, the primary lumen having a greater cross-sectional size than the secondary lumen, wherein the primary lumen is configured to receive a lead therein and to permit the lead to move relative to the catheter; and a catheter electrode located at or proximate to the distal end of the catheter body; and an active wire within the secondary lumen of the catheter body, the active wire including a tip electrode at a distal end of the active wire, the active wire configured to be moved relative to the catheter to advance a distal segment of the active wire beyond the distal end of the catheter body to pierce the myocardial tissue at the SOI.