| Pulmonary vein | |
|---|---|
.svg) Anterior (frontal) view of the opened heart. White arrows indicate normal blood flow. | |
 Diagram of the alveoli with both cross-section and external view. | |
| Details | |
| Precursor | Truncus arteriosus |
| System | Circulatory system |
| Drains from | Lungs |
| Drains to | Left atrium |
| Artery | Pulmonary artery |
| Identifiers | |
| Latin | venae pulmonales |
| MeSH | D011667 |
| TA98 | A12.3.02.001 |
| TA2 | 4107 |
| FMA | 66643 |
| Anatomical terminology | |
Thepulmonary veins are theveins that transferoxygenated blood from thelungs to theheart. The largest pulmonary veins are the fourmain pulmonary veins, two from each lung that drain into theleft atrium of the heart. The pulmonary veins are part of thepulmonary circulation.
There are fourmain pulmonary veins, two from each lung – an inferior and a superior main vein, emerging from eachhilum. The main pulmonary veins receive blood from three or four feeding veins in each lung, and drain into theleft atrium. The peripheral feeding veins do not follow the bronchial tree. They run between the pulmonary segments from which they drain the blood.[1]
At the root of the lung, the right superior pulmonary vein lies in front of and a little below the pulmonary artery; the inferior is situated at the lowest part of the lung hilum. Behind the pulmonary artery is thebronchus.[2] The right main pulmonary veins (contains oxygenated blood) pass behind theright atrium andsuperior vena cava; the left in front of the descendingthoracic aorta.[citation needed]
Occasionally the three lobar veins on the right side remain separate, and not infrequently the two left lobar veins end by a common opening into the left atrium. Therefore, the number of pulmonary veins opening into the left atrium can vary between three and five in the healthypopulation.[citation needed]
The two left lobar veins may be united as a single pulmonary vein in about 25% of people; the two right veins may be united in about 3%.[2]
The pulmonary veins play an essential role inrespiration, by receiving blood that has been oxygenated in thealveoli and returning it to the left atrium.[citation needed]
As part of the pulmonary circulation they carry oxygenated blood back to the heart, as opposed to the veins of thesystemic circulation which carry deoxygenated blood.[citation needed] By definition, avein is a blood vessel that carries blood to the heart, whether oxygenated or deoxygenated.
A groundbreaking study published in 1998 identified the pulmonary vein as the predominant trigger foratrial fibrillation.[3] Atrial fibrillation frequently results from bursts oftachycardia that originate in muscle bundles extending from theatrium to the pulmonary veins.[4] Pulmonary vein anatomy is highly variable among atrial fibrillation patients.[5] Pulmonary vein isolation bytranscatheter ablation can restoresinus rhythm.[4] As atrial fibrillation becomes more persistent, the junction between the pulmonary veins and theleft atrium becomes less of an initiator and the left atrium becomes an independent source of arrhythmias.[6] Pulmonary vein isolation ablation technology has used thermal methods (radiofrequency ablation orcryoablation), which can damage adjacent tissues, notably theesophagus, lung orphrenic nerve.[7]Electroporation, however, eliminates the risk of thermal damage.[7] Atrial fibrillation most often recurs after ablation because of pulmonary vein reconnection.[8]
On chest X-ray, the diameters of pulmonary veins increases from upper to lower lobes, from 3 mm at the first intercoastal space, to 6 mm just above the diaphragm.[9]
A raregenetic defect of the pulmonary veins can cause them to drain into the pulmonary circulation in whole or in part, this is known as a totalanomalous pulmonary venous connection (or drainage), or partial anomalous pulmonary connection, respectively.[citation needed]
This article incorporates text in thepublic domain frompage 642 of the 20th edition ofGray's Anatomy(1918)
