Evolution of ventricular septal defect with special reference to spontaneous closure rate, subaortic ridge and aortic valve prolapse.

The medical records of 685 patients with ventricular septal defect (VSD) were reviewed to determine spontaneous closure, left ventricular-to-right atrial shunt, subaortic ridge, and aortic valve prolapse. Patients had been followed for a mean of 3 +/- 2.5 years and median 2.2 years by echocardiography. VSD was perimembranous in 65.7% (450), trabecular muscular in 30.8% (211), muscular outlet in 2.3% (16), muscular inlet in 0.7% (5), and doubly committed subarterial in 0.5% (3). Defect size was classified in 76% (517) as small, in 18% (124) as moderate, and in 6% (44) as large. VSD closed spontaneously in 27% (186 of 685 patients) by ages 40 days to 13.7 years (mean, 2.1 +/- 2.2 years; median, 1.3 years). Sixty-six of 450 perimembranous defects (15%) and 120 of 211 trabecular muscular defects (57%) closed spontaneously (p <0.001). Defect size became small in 15% of patients with VSD at mean 2.9 +/- 2.3 years (median, 2.3 years). Aneurysmal transformation was detected in 56% (254), left ventricular-to-right atrial shunt in 8.4% (38), subaortic ridge in 5.8% (26), aortic valve prolapse in 11.7% (53), and aortic regurgitation in 7.3% (33) of 450 patients with perimembranous defect. There was no statistical significance between the age at closure and the age of detection of aneurysmal transformation in the patients with perimembranous defect (p = 0.25).