Left ventricular function in adult patients after the atrial switch operation for transposition of the great arteries

OBJECTIVES: Right ventricular function may deteriorate after the atrial switch operation in patients with transposition of the great arteries, but the effect on left ventricular function is unknown. Chronic left ventricular function was evaluated in adult patients after the atrial switch operation for transposition of the great arteries. METHODS: Right and left ventricular functions were evaluated using data from cardiac catheterization performed in nine patients older than 17 years who had undergone the atrial switch operation for transposition of the great arteries. The mean age at operation was 19 +/- 16 months and the age at catheterization ranged from 17 to 32 years (mean age 23 +/- 5 years). Echocardiography was performed in all patients to evaluate tricuspid regurgitation. Myocardial perfusion studies using technetium-99 m-tetrofosmin were assessed in five patients. RESULTS: Mean right ventricular end-diastolic volume was slightly increased to 122 +/- 27% of the normal value and mean right ventricular ejection fraction was depressed to 44 +/- 5% of the normal value. Left ventricular ejection fraction ranged from 37% to 63% (mean 50 +/- 7%) and was under 50% in four of the nine (44%) patients. Right ventricular ejection fraction was positively correlated with left ventricular ejection fraction(r = 0.72, p < 0.05). All patients had tricuspid regurgitation, mild in four, moderate in four, and severe in one patient. Left ventricular ejection fraction was lower in patients with moderate or severe tricuspid regurgitation(54 +/- 4%) than in patients with mild tricuspid regurgitation(47 +/- 6%, p < 0.05). Mild or moderate perfusion abnormalities were observed in all patients (five of five) who underwent myocardial perfusion studies. Mean right and left ventricular ejection fractions were 43 +/- 3% and 50 +/- 3%, respectively, in patients who underwent myocardial perfusion study, which were under the normal levels. CONCLUSIONS: Left ventricular dysfunction is common in adult patients after the atrial switch operation for transposition of the great arteries. Some right ventricular abnormalities may correlate with the left ventricular dysfunction.