Prevalence at birth, “natural” risk and survival with atrioventricular septal defect

Abstract

SummaryPrevalence of atrioventricular septal defect in liveborn infants at birth was calculated in Bohemia (population of 6.3 million). Of 664,208 liveborn infants, 4,409 had a congenital malformation of the heart and in 126 of them (0.19/1,000 live births, 2.9% of all heart defects) this was found to be an atrioventricular septal defect. The ratio between those with a common valvar orifice (complete form) versus those with separate right and left atrioventricular valvar orifices (incomplete form) was 1.14:1. The ratio of girls to boys was 1.17:1. Children born in March, July and October were more likely to have the defect (0.26/1,000 live births) than those born in May (0.10/ 1,000 live births). The defect was the eighth most frequent critical congenital cardiac malformation. Eight in each 100,000 liveborn children, and 3.56% of all patients with congenital cardiac disease, are at high risk of dying due to deficient atrioventricular septation, which in 82.5% resulted in the presence of a common atrioventricular valve (complete form). Unconditional death rate was studied in 1,008 liveborn children who died with a cardiac malformation before the age of 15 before the advent of cardiac surgery. Of these, 64 (6.35%) died with an atrioventricular septal defect which was complete in 5.95% and incomplete in 0.40%. All but one of 60 children with the complete form (common atrioventricular valve) died in the first year of life. The last child died between the age of 2 and 5 years. The estimate for natural survival was calculated using our own data on the prevalence and age distribution of mortality. Of all the liveborn children with atrioventricular septal defect, 91% are expected to survive the first month, 81% (78−85) the first trimester, 63% (56−69) six months, and 49% (35−54) the first year. The survival curve remains stable thereafter.