Improvement in noninvasive electrophysiologic findings in children after transcatheter atrial septal defect closure.

To evaluate whether transcatheter closure of secundum atrial septal defects (ASD) affected noninvasive electrophysiologic variables in children, we reviewed the pre-procedural and 1-year postprocedural electrocardiograms and Holter recordings of 18 consecutive children referred for ASD closure. Patients included in the study were a mean of 5.0 years old (SD 1.1) and weighed a mean of 17.9 kg (SD 4.1). ASDs had a mean diameter of 14.0 mm (SD 2.4) and average shunt ratio (pulmonary-to-systemic flow) of 2.1:1. One year after occluder device placement, 9 children (50%) had detectable residual shunts by transthoracic echocardiograms, but only 2 (11%) had shunts that were felt to be possibly significant. One or more fractured occluder legs were noted by chest roentgenogram in 15 patients (83%). Electrocardiograms at follow-up demonstrated improvement in right ventricular dilation in 4 of 7 patients, right atrial enlargement in 3 of 4 patients, and 1 degree atrioventricular block in 2 of 3 patients. Holter recordings showed a decreased incidence of accelerated atrial rhythm in 3 of 7 patients, prolonged junctional escape rhythm in 2 of 2 patients, and premature atrial contractions in 2 of 2 patients. No finding correlated with patient age, defect or occluder diameter, occluder leg fracture(s), or residual defects. These improvements in electrophysiologic abnormalities compare favorably with changes seen 1 year after surgical closure. In conclusion, placement of a transcatheter ASD device in children diminishes noninvasive electrophysiologic abnormalities at 1-year follow-up. By relieving hemodynamic stress caused by an ASD in childhood, a transcatheter device may prevent arrhythmia disturbance later in life.