Echocardiographic features of patients with and without residual defects after Mustard's procedure for transposition of the great vessels.

The usefulness of echocardiography in evaluating patients who have undergone Mustard's pro- cedure for d-transposition of the great vessels was investigated by examining the M-mode studies and cardiac catheterization data of 20 patients at least 1 year after operation. The patients were separated into two groups using the findings at cardiac catheterization. The 12 patients in group 1 were asymptomatic, were not taking cardiac medications and were free of significant residual hemodynamic defects. Echocardiographically, left ventricular diastolic dimension (LVDD) and posterior wall size (PW) were smaller than normal in these children, whereas right ventricular diastolic dimension (RVDD) and anterior wall thickness (AW) were greater than normal. The percent fractional shortening of the left ventricle (%FS) was elevated. Systemic venous atrial-to-pulmonary venous atrial dimension ratios (SVA/PVA) fell into a narrow range regardless of patient size (mean 1.00 0.06) (SD). All patients in group 1 had diastolic flutter of both atrioventricular valves and ab- normal septal motion.. Two patients had systolic flutter of the pulmonary valve and nine had systolic anterior motion of the mitral valve. The eight patients in group 2 had significant residuai defects. In all five patients with baffle obstruction of systemic venous return and in the patient with baffle obstruction of pulmonary venous return, SVA/PVA was well outside group 1 limits..RVDD was above group 1 limits in one patient with RV dysfunction andAtwo with tricuspid insufficiency. Pulmonary artery diameter, LVDD, and PW were above the respective group 1 ranges in two patients with elevated pulmonary artery pressure, while pulmonary artery diameter was below. group 1 limits in the patient with pulmonic stenosis. All group 2 patients were easily distinguishable from group 1 patients by at least one variable. Thus, while marked echocardiographic differences exist between group 1 and normal patients, patients with residual defects after the Mustard procedure can be readily identified, indicating a useful role for echocardiography in the postoperative management of patients with transposition of the great vessels.