The natural history of ventricular septal defects

Aims-To correlate the size and position of isolated ventricular septal defe cts with closure rate in a cohort of children with mean follow up of more t han six years. Design-A birth cohort was identified using the northern region cardiac data base. The following were noted from case notes: defect size, position, mean s of closure, and age at closure. Results-68 children were identified. 49 defects were small, 14 were moderat e, and 5 were large. 13 cases required surgical closure, including 12 perim embranous defects. 35 defects closed spontaneously. Nine of the small muscu lar defects remained open and five of the small perimembranous defects rema ined open. The spontaneous closure rate for muscular defects was significan tly greater than for perimembranous defects. Mean age of follow up for pati ents who still have defects is 76 months. Conclusions-The position of; a ventricular septal defect is extremely relev ant to its natural history. Perimembranous defects accounted for most of th e moderate and large defects that required surgical intervention. After mor e than six years almost a third of all perimembranous and just over two thi rds of all muscular defects closed spontaneously.