LAUSR

Constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM) are serious disorders that share common pathophysiologic elements including biventricular diastolic dysfunction, elevated biatrial pressures, and reduced resting cardiac output. Yet,while these 2 disorders have similar clinical presentations, they are caused by very different pathologicprocesses,whichhavedistinct implications for treatment. CP is potentially curable by surgical pericardiectomy, whereas therapeutic options for RCM are limited. A mistakenlyundertakensurgicalpericardiectomyinapatientwithRCM wouldbehighly inappropriate. Consequently, accuratedifferentiation between these 2 superficially similar disorders is of paramount clinical importance. The report by Jain et al1 in this issue of JAMA Cardiology describes a simplification of an established technique that aids in distinguishing these 2 groups of disorders.