Spontaneous "cardiomegaly" following pericardiectomy.

A 64-year-old woman presented eight days following pericardiectomy with a 2-day history of progressive dyspnea and new crushing chest pain. Chest x-ray revealed development of interval "cardiomegaly." Bedside echocardiography revealed a large accumulation of pericardial fluid despite absence of pericardium. Diagnostic and therapeutic mediastinocentesis was performed and confirmed the diagnosis of mediastinal hemorrhage. Subsequent to pericardiectomy, mediastinal hemorrhage can masquerade as cardiomegaly and may require urgent intervention.