[Evolution of ventricular septal defects. Relation to echocardiographic anatomy]

The aim of this study was to analyse the outcome of membranous ventricular septal defects (VSD) with respect to the echocardiographic data obtained during the first year of life. This retrospective series included patients born between January 1st 1986 and December 31st 1995, in the Indre et Loire department, with membranous ventricular septal defects alone or associated with minor abnormalities. The initial echocardiography, an echocardiography performed 2 to 6 months later, one a year later and the final echocardiography were compared. Three groups of VSD were constituted according to their diameter: group I (< or = 3 mm), group II (3-6 mm), and group III (> 6 mm). Depending on the outcome, the patients were classified as spontaneous closure (group A), surgical closure (group B) or persistent VSD (group C). The population comprised 84 children. There were 6 spontaneous deaths, three of which were unexplained, and 7 children were lost to follow-up. After the initial echocardiography, the VSD were classified as group I (38%), group II (26.2%) and group III (35.7%). After the second echocardiogram, 24 VSD changed group (31.5%), by increase (N = 10) or decrease (N = 14) in diameter. Aneurysms of the membranous septum were observed during the first two echocardiographies in 31.2% and 79.3% of VSDs of group I, 31.8% and 70% of VSDs of group II and 6.6% and 3.3% of VSDs of group III (p < 0.01). The average follow-up was 3.1 years (range 1 month-10 years). In group A (N = 22), the mean age of closure of the VSD was 26 months (3 months-7 years). In group B (N = 28), surgery was undertaken at an average age of 10 months (range 3 months-5 years). In group C (N = 21), the VSDs were classified as group I (N = 19) or group II (N = 2) at the last echocardiography. The frequency of aneurysms of the membranous septum in groups A, B and C were respectively 100%, 7.1% and 66.6% (p < 0.01). At the second echocardiographic examination, a significant relationship (p < 0.001) was observed between the diameter of the VSDs and their outcome. The VSDs of group A were associated with aneurysms of the membranous septum more often than those of group C (p < 0.005). The authors conclude that surgery is required in about one third of membranous VSD. At medium term, the others either close spontaneously or become smaller in comparable numbers. The outcome is directly related to the diameter of the VSD and the development of an aneurysm of the membranous septum. During the first 6 months, the dimensions of membranous VSDs change in about 30% of cases with an increase in frequency of aneurysms of the membranous septum.