Left ventricular septal aneurysm.

A6-month-old girl (3.5 months corrected, born at 28 weeks gestational age) presented with a history of increasing tachypnea, diaphoresis, difficulty feeding, and poor weight gain. A 15-lead ECG done on day 41 of life had revealed normal sinus rhythm with a nonspecific intraventricular conduction delay. At that time, clinically there was a soft systolic murmur and no evidence of congestive heart failure. An echocardiogram revealed a structurally normal heart with a moderate-size patent ductus arteriosus shunting left to right, a small secundum atrial septal defect shunting left to right, and mildly reduced left ventricular function secondary to a dyskinetic interventricular septum (Figure 1). She was discharged clinically well at 3 months of age (corrected age, 40 weeks). On this subsequent presentation, she manifested clinical signs of mild congestive heart failure with tachypnea, fine inspiratory crackles, an intermittent gallop, and a liver palpable at 2 to 3 cm below the costal margin. A chest radiograph revealed moderate cardiomegaly with pulmonary congestion. The ECG revealed normal sinus rhythm with first-degree atrioventricular block and nonspecific intraventricular conduction delay. Transthoracic echocardiography revealed an aneurysm of the interventricular septum (Figure 2).