Pseudoaneurysm of the left ventricle progressing from a subepicardial aneurysm

A 56-year-old man presented with an inferior myocardial infarction and a hu ge pseudoaneurysm below the inferior surface of the left ventricle, which h ad progressed from a small subepicardial aneurysm over a 6-month period. Tr ansthoracic echocardiography, Doppler color flow images, radionuclide angio cardiography, magnetic resonance imaging and contrast ventriculography all revealed an abrupt disruption of the myocardium at the neck of the pseudoan eurysm, where the diameter of the orifice was smaller than the aneurysm its elf, and abnormal blood flows from the left ventricle to the cavity through the orifice with an expansion of the cavity in systole and from the cavity to the left ventricle with the deflation of the cavity in diastole. Corona ry angiography revealed 99% stenosis at the atrioventricular nodal branch o f the right coronary artery. At surgery the pericardium was adherent to the aneurysmal wall and a 1.5-cm orifice between the aneurysm and the left ven tricle was seen. Pathological examination revealed no myocardial elements i n the aneurysmal wall. The orifice was closed and the postoperative course was uneventful. Over-intense physical activity as a construction worker was considered to be the cause of the large pseudoaneurysm developing from the subepicardial aneurysm. These findings indicate that a subepicardial aneur ysm may progress to a larger pseudoaneurysm, which has a propensity to rupt ure, however, it can be surgically repaired.