Subepicardial aneurysm with impending cardiac rupture: a case of antemortem diagnosis and review of the literature.

Subepicardial aneurysm is a rare, life-threatening complication of acute myocardial infarction. Relatively few cases are diagnosed early enough to allow for surgical intervention. Features of this unique aneurysm include abrupt interruption of the myocardium, a narrow neck, and a propensity for progressing to sudden transmural rupture. Literature review reveals only 20 reported cases, several of which were identified postmortem. Since the myocardial burrow may progress to pseudoaneurysm or frank rupture prior to the diagnosis being made, the true incidence is unknown. Invariably, the condition develops as a result of a myocardial rent occurring during the weeks to months following acute infarction, and it generally occurs within an area of thinned, infarcted myocardium. Successful surgical repair has been reported in several cases and is the only therapy shown to prevent progression to frank rupture. Antemortem diagnosis has been reported with transthoracic echocardiography, transesophageal echocardiography, cardiac catheterization, and magnetic resonance imaging. Unfortunately, each of these imaging techniques appears to be limited by either inadequate sensitivity or slow acquisition. There remains no standard of reference among available diagnostic modalities. Rapidly obtained, contrast-enhanced computed tomography in the proper clinical setting may improve the ability of clinicians to identify this condition during a window of therapeutic opportunity, allowing surgical intervention to prevent fatal cardiorrhexis. Subepicardial aneurysm should be included in the differential diagnosis for patients presenting with chest pain following acute myocardial infarction. Copyright (c) 2007 Wiley Periodicals, Inc.