Enlarged right ventricular size at 11 years' follow-up after closure of secundum-type atrial septal defect in children.

Background: The fate of right ventricular dimensions after surgical closure of secundum-type atrial septal defects remains unclear. The objectives of this study were to assess ventricular dimensions, exercise capability, and arrhythmias of patients operated for secundum-type atrial septal defect and compare the results with those in healthy references.

Methods: A total of 78 consecutive patients underwent surgical closure for a secundum-type atrial septal defect between 1990 and 1995. In all, 42 patients were included and underwent a cross-sectional evaluation including echocardiography, magnetic resonance imaging, exercise testing, and 24-hour ambulatory electrocardiography. Patients were matched with healthy controls for gender, body surface area, and age.

Results: The mean age at surgery was 4.6 plus or minus 2.8 years, and the mean age at follow-up was 16 plus or minus 3 years. There were no residual intracardiac lesions. The mean right ventricular endsystolic volume was significantly larger in patients (142 ± 26 millilitres) than in references (137 ± 28 millilitres; p = 0.04). In 25% of the patients, right ventricular end-systolic volume was larger than the 95th percentile for references. No relevant arrhythmias were detected. Exercise testing did not reveal differences with healthy references: maximal power (169 ± 43 Watt patients versus 172 ± 53 controls; p = 0.8), maximal oxygen uptake (38 ± 8 versus 41 ± 13 millilitres per minute per kilogram; p = 0.1).

Comment: After surgical closure of secundum-type atrial septal defect, right ventricular end-systolic volume is increased. These findings have no impact on rhythm status or exercise capacity at this stage of follow-up, but may have implications for the timing of surgery or the technique of closure if confirmed in longer follow-up.