Importance of spontaneous closure of the ventricular part in atrioventricular septal defect.

The clinical features, hemodynamic changes and prognosis of 21 children with simple atrioventricular septal defect (3 associated with patent ductus arteriosus) were studied during a follow-up period of 1 month to 13 3/12 years (median 3 years). Six patients had spontaneous closure of the ventricular part of the defect within 22.2 +/- 27.7 months (Group I). The symptoms and signs of failure to thrive, frequent respiratory tract infections and congestive heart failure were more common in patients without spontaneous closure of the ventricular part of atrioventricular septal defect (Group II) than in patients in Group I. The Qp/Qs ratio, pulmonary vascular resistance and pulmonary to systemic resistance ratio were also higher in Group II than in Group I. In spite of a higher postoperative mortality rate and a higher incidence of transient complete heart block, the children in Group II also had a significantly higher (p less than 0.005) preoperative mortality rate than those in Group I. In conclusion, if the ventricular part of the atrioventricular septal defect closed or was closing spontaneously, symptoms and signs were less severe and there was a better prognosis.