Atrioventricular septal defect (AVSD)is a complex heart malformation affecting the lower part of atrial septum, the highest aprt of ventricular septum, mitral and tricuspid valves. It represents 3 to 7.3 % of congenital heart diseases. It is responsible for an important part of early death.

The objective of this study is to precise clinical, echocardiographic and prognostic profile of AVSD in adults.

Descriptive, retrospective, transversal and monocentric study conducted in a period of 10 years between December 2008 and December 2018. Were included all patients of more than 18 years presenting with an AVSD confirmed by echocardiography and followed in the congenital heart disease unit of our department.

Three hundred and thirteen patients were collected. Among them, 31 were adults (9,9 %).16 patients were aged more than 30. The oldest patient had 56 years old. Sex ratio was H/F=0,48. One patient was trisomic 21. The mean SpO2 was 91,87±8,25%. Partial AVSD was mostly represented (17 cases), then complete AVSD (12 cases among which 8 type C et 4 type A of Rastelli), then intermediate AVSD (2 cases). Pulmonary arterial hypertension was present in 16 patients (51,6%) of cases, one patient was diagnosed Eisenmeger syndrome. 22,6% underwent curative surgery. Amogn +the 31 patients, 4 deaths, mortality was statistically lower than in younger patients (P<0,001).

AVSD, particularly in its complete form, is a dangerous pathology. The diagnosis at adult age seems to have a better prognosis. Treatment is essentially surgical, the nit is important to assess the diagnosis earlier.