[Left ventricular diverticulum: a report of two cases].

Left ventricular diverticulum is a rare congenital cardiac malformation, and is classified as muscular and fibrous. Muscular diverticula are usually associated with thoracoabdominal defects and arise from the cardiac apex. We encountered two cases of muscular left ventricular diverticulum without other congenital anomalies during the review of 3,000 left ventriculograms. Both patients were men and their diverticula were located along the inferior left ventricular wall. No symptoms were associated with the diverticula. In both cases, two-dimensional echocardiography detected the diverticula, thus this is regarded as a useful method for the diagnosis and screening of this anomaly. In one of our cases, thallium myocardial imaging also demonstrated a characteristic abnormal bulge corresponding to the diverticulum. We subsequently detected two more cases of muscular left ventricular diverticula among 300 left ventriculograms. Thus, we detected four cases of left ventricular diverticula among 3,300 left ventriculograms. Although only 11 cases of muscular left ventricular diverticulum previously have been reported, this anomaly is not so rare as previously supposed, and it should be distinguished from left ventricular aneurysm.