Incidence of spontaneous closure of outlet ventricular septal defect.

The present study examined the Doppler echocardiograms of 742 patients with an outlet ventricular septal defect (VSD) who were seen at the National Cardiovascular Center from 1987 to 1999. Of these, 450 patients were followed for longer than 1 year; 161 of these 450 were younger than 12 months when first examined. During follow-up, Doppler echocardiographic examination was repeated at least once a year. The medical charts of these patients were reviewed. Doppler echocardiographic findings were analysed in patients whose defect closed spontaneously:spontaneous closure at the age of 1-25 years was identified in 17 (3.8%) of 450 patients who were followed for longer than 1 year, and 7 (4.3%) of the 161 patients who were younger than 12 months at the first examination. All closed VSDs were originally smaller than 4mm. Although 5 cases of 17 developed trivial deformity of the right coronary cusp, suggesting a prolapse, this did not progress. Of these 5, trivial aortic regurgitation (AR) was detected in one patient, while another patient in the group of 17 developed trivial AR without any deformity of the right coronary cusp. Aortic regurgitation was not progressive in either patient. An outlet VSD closes spontaneously in a small percentage of patients without developing progressive AR.