Subepicardial left ventricular aneurysm with ventricular septum perforation

Abstract

An 88-year-old woman with no history of heart disease and diabetes mellitus was admitted to our hospital because of acute heart failure without chest pain. Vital signs were stable, but abnormal systolic heart sounds were detected in the left fourth intercostal space. Electrocardiography showed sinus rhythm with low amplitude in the limb lead, inferior Q waves and 1-mm ST-segment elevation, suggesting inferior MI. Repeat serum cardiac markers were normal, indicating non-acute MI, although chest radiography showed cardiomegaly, pulmonary congestion, and bilateral pleural effusion, suggesting acute heart failure. Transthoracic echocardiography showed abrupt interruption of the inferior myocardial wall, a 20 × 37 mm aneurysm communicating with the left ventricle, and abnormal shunt flow from the aneurysm into the right ventricular (RV) cavity detected using color flow Doppler (Fig. 1a, b). Cardiac multislice computed tomography (CT) revealed a narrow-neck LV inferobasal aneurysm communicating with the RV cavity, diagnostic of a subepicardial aneurysm and ventricular septum perforation (Fig. 1c, d). CT coronary angiography revealed a 90% lesion in the proximal right coronary artery with severe calcification. We recommended aneurysmectomy and repair of the ventricular septum perforation, which she refused. Conservative medical treatment with diuresis and vasodilating agents was continued, and her clinical status improved. She was discharged home in stable condition 50 days after admission. She remains asymptomatic and hemodynamically stable 4 years later. The term “subepicardial aneurysm,” as used in this case, was first applied by Epstein and Hutchins in 1983 [1]. This unique aneurysm is a rare, serious form of subacute cardiac rupture complicating MI, abruptly interrupting the myocardium, with its narrow neck and thin wall containing only epicardium with or without a thin myocardial layer [2, 3]. A rapid, correct diagnosis could help establish the therapeutic strategy, including surgery to prevent fatal cardiac rupture. When diagnosing LV aneurysms, subepicardial aneurysms should be distinguished from true aneurysms, pseudoaneurysms, and diverticula [3, 4]. In our case, multislice CT was useful because it provided morphological information about the aneurysm [3]. Surgery is recommended in such cases to avoid rupture. Although reported surgical success rates are high [3, 4], our patient refused it. Thus, under conservative care, she remains asymptomatic and hemodynamically stable 4 years later. We speculated that the reason the aneurysm did not progress to fatal cardiac rupture was its communication with the right ventricle via the perforated ventricular septum, thereby reducing the aneurysm’s inner pressure. Generally, however, surgery is recommended to avoid risking rupture.