Long-term Noninvasive Arrhythmia Assessment after Surgical Repair of Sinus Venosus Atrial Septal Defect

Objective: The sinus venosus atrial septal defect (SVASD) has been successfully repaired with low risk for many years. Postoperative arrhythmias have not been comprehensively described. We sought to define the prevalence of late arrhythmias after surgical closure of the SVASD. Design: We performed a cross-sectional noninvasive arrhythmia evaluation of patients ≥6 years of age, who had surgical repair of an isolated SVASD at a single institution from 1987 to 2004, to assess for sinus node dysfunction (SND), atrioventricular (AV) block, and atrial and ventricular arrhythmias. Evaluation included an electrocardiogram, echocardiogram, 24-hour Holter monitor, and exercise stress test. Results: Thirty subjects were evaluated 10.1 ± 4.7 years (range 3.3-20.4 years) after operative repair. Mean age at surgical repair was 6.4 ± 8.1 years (range 1.3-45.7 years). Anatomic subtype was either superior vena cava- (SVC) (n = 24) or inferior vena cava- (IVC) type (n = 6). Type of surgical repair included: single patch (n = 13), double patch (n = 6), and Warden (n = 5) for SVC-type. All IVC-type had single patch repair. Overall, 50% (n = 15) of patients showed some evidence of SND, which is significantly associated with a longer duration of follow-up (P=03). High-grade AV block and complex tachyarrhythmias were not seen. Conclusions: We conclude that postoperative SVASD patients have a significant prevalence of SND, which may increase with duration of follow-up. These patients warrant ongoing clinical surveillance for the potential development of signs and symptoms of SND.