Atrial and ventricular septal defects - epidemiology and spontaneous closure

To present data on the epidemiology and spontaneous closure for septal defects (secundum atrial septal defect (ASD) and/or ventricular septal defect (VSD)).

Data from the EUROCAT Registry of Congenital Malformations for Funen County, Denmark were analyzed. All infants born from 1986 to 1998, diagnosed with a secundum ASD and/or a VSD as the only cardiac malformation, were included.

There were 78 infants with an ASD, 195 with a VSD, and 19 had both an ASD and a VSD. The overall prevalence of septal defects was 4.1 per 1000 livebirths. Among the VSDs 45% were perimembranous and 55% were muscular defects. Associated non-cardiac malformations, syndromes, or karyotype anomalies were present in 54 cases (19% of total) but with a significantly lower proportion among cases with muscular VSDs (7%, p < 0.05). Eighty-one percent of the cases had an isolated cardiac malformation. Five of 61 cases (8%) with isolated ASD were closed surgically before five years of age and 43 (70%) closed spontaneously within the first five years of life. Of the 65 cases with isolated perimembranous VSDs, 13 were closed surgically (20%) and 13 closed spontaneously (20%). Of the 99 cases with isolated muscular VSDs no defects were closed by surgery and 64 (65%) closed spontaneously. The rate of spontaneous closure for perimembranous and muscular VSDs were significantly different (p < 0.0001).

Secundum ASD has a high rate of spontaneous closure. Perimembranous and muscular VSDs seem to be two different diseases with different epidemiology and natural history.