Echocardiographic evaluation of the systemic ventricle after atrial switch procedure. The usefulness of subcostal imaging.

BACKGROUND Subcostal planes allow demonstration of the entire right ventricular cavity and are frequently used in patients with congenital heart disease; however, their clinical utility in the evaluation of systemic right ventricular function after atrial switch procedure for complete transposition has never been verified in adolescent and adult patients. METHODS In unselected patients with simple transposition who had had an atrial switch performed between 1982 and 1990, echocardiographic and myocardial perfusion imaging were performed. Systolic function of the right ventricle was assessed from the subcostal window, and the right ventricular area change was calculated. Right ventricular systolic function was defined as impaired when the right ventricular area change was equal to or less than 0.35. RESULTS Sixty [43 male and 17 female, mean age (standard deviation) 14.9 (4.5) years] patients were included in the analysis. Echocardiographic right ventricular area change ranged from 0.14 to 0.66 [0.42 (0.12)]. Twenty-one patients (35%) had significant impairment of right ventricular systolic function [0.29 (0.06)]. Right ventricular area change equal to or less than 0.35 detected moderate-to-severe perfusion abnormalities with 78% sensitivity and 62% specificity. CONCLUSIONS Right ventricular area change evaluated from the subcostal plane provides significant clinical information in patients with complete transposition. A cutoff value of 0.35 can be used as an indication of right ventricular impairment associated with significant perfusion abnormalities.