To study the potential for recovery of left ventricular function in patients with anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) after aortic reimplantation, serial two-dimensional echocardiographic examinations were performed before and up to 9 months after operation in 11 consecutive paediatric patients (group 1: six infants; group 2: five children above the age of 1 year). End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), myocardial volume (MV), ratio of myocardial volume/end-diastolic volume (MVI), and regional wall motion of the left ventricle (LV) were studied. Pre-operatively, mean LVEDV was 339% of normal in group 1 and 289% in group 2 (P < 0.001); mean LVMV was about twice the normal value in both groups (P < 0.001); LVMVI was 0.79 +/- 0.23 in group 1 and 0.83 +/- 0.3 in group 2; LVEF was 28 +/- 10% in group 1 and 46 +/- 18% in group 2; regional wall motion was normal in two group 2 patients, the other showed uniform reduction in segmental shortening fraction. Postoperatively, mean LVEDV tended to become normal after 2 weeks in group 1 and after 3 months in group 2. In both groups mean LVEF reached the normal range after 3 months; LVMV as well as LVMVI normalized after 9 months. Three months after the operation, all infants had a nearly normal pattern of regional wall motion, while in three group 2 children a residual reduced shortening fraction could be observed in anterior or lateral segments.(ABSTRACT TRUNCATED AT 250 WORDS)