Exercise Capacity Long-Term after Arterial Switch Operation for Transposition of the Great Arteries.

Abstract

Transposition of the great arteries (TGA) is a congenital heart defect successfully corrected through arterial switch operation (ASO). Although this technique had significant impact in improving survival, little is known about the functional capacity of the operated patients long-term after surgery. The aim of this study was to compare the functional capacity of children with TGA long-term after ASO with that of healthy children. Retrospective study. All patients that performed cardiopulmonary exercise test (CPET) were included in the study. As a control group, healthy children in evaluation for physical activity that performed CPET during the same period were also enrolled. Thirty-one TGA patients (19 male) were compared with 29 age-matched controls (21 male). Maximum oxygen consumption was higher in the control group (45.47 ± 8.05 vs. 40.52 ± 7.19, P = .017), although within normal limits in both groups (above 90% of predicted value). The heart rate behavior during exercise was different in both groups, with a mean chronotropic index significantly lower in the TGA group (63% ± 14 vs. 81% ± 12, P < .001). Our results showed that exercise capacity long-term after ASO in TGA is well preserved although lower than in healthy children what might be explained by the presence of chronotropic incompetence in the TGA group.