Surgical management of localized left ventricular aneurysm associated with acute myocarditis

We present a case of a localized left ventricular (LV) aneurysm in a 72-year-old woman with sudden onset of severe chest pain. A left ventriculogram revealed a small saccular outpouching protruding from the apex accompanied with narrow neck connection to the ventricular cavity. Both coronary arteries and global function were normal. We preoperatively diagnosed her as having an impending rupture in the congenital LV diverticulum because no inflammatory myocardial disease was suggested by general laboratory tests. After successful surgical treatment, microscopic examination for the myocardial specimens was performed and revealed diffuse lymphocytic infiltration associated with focal necrosis of myocardium. Histological findings were consistent with those of acute lymphocytic myocarditis. Without histological confirmation, an aneurysm caused by silent myocarditis might be misdiagnosed as a diverticulum.