Most patients with acute pericarditis have a benign course and a good prognosis. However, a minority of patients develop complicated pericarditis, and the care of these patients is the focus of this review. Specifically, we address risk factors, multimodality imaging, pathophysiology, and novel treatments. The authors conclude that: 1) early high-dose corticosteroids, a lack of colchicine, and an elevated high-sensitivity C-reactive protein are associated with the development of complicated pericarditis; 2) in select cases, cardiovascular magnetic resonance imaging may aid in the assessment of pericardial inflammation and constriction; 3) given phenotypic similarities between recurrent idiopathic pericarditis and periodic fever syndromes, disorders of the inflammasome may contribute to relapsing attacks; and 4) therapies that target the inflammasome may lead to more durable remission and resolution. Finally, regarding future investigations, the authors discuss the potential of cardiovascular magnetic resonance to inform treatment duration and the need to compare steroid-sparing treatments to pericardiectomy.