Reappraisal of Left Ventricular to Right Atrial (LV-RA) Shunt in Pediatric Patients With Isolated Perimembranous Ventricular Septal Defect

Background The purpose of this study was to investigate the follow-up results of perimembranous ventricular septal defect (VSD) with left ventricular to right atrial (LV-RA) shunt since infancy and to analyze the morphologic variations of this shunt. Methods and Results The study group comprised 232 consecutive pediatric patients with isolated perimembranous VSD and aneurysm, of whom 134 (58%) had LV-RA shunts. Follow-up echocardiography was performed to assess for the size of both the VSD and LV-RA shunt. There were no significant differences between groups in terms of sex, age at the initial echocardiography, follow-up period, number of patients with tricuspid regurgitation, and initial VSD size. There was a significant difference between groups in spontaneous closure (p=0.039). The event-free probability (no surgical repair of the defect) was not significantly different between the groups (p=0.129). Conclusions Perimembranous VSD with LV-RA shunt in infancy is common and associated with less chance of spontaneous closure. Color Doppler echocardiography can greatly improves the diagnostic efficacy and assist in understanding the mechanisms leading to this particular anomaly. (Circ J 2008; 72: 1487 - 1491).