Common atrioventricular valve guarding double inlet atrioventricular connexion: natural history and surgical results in 76 cases.

We describe 76 patients in whom a double inlet atrioventricular connexion was guarded by a common atrioventricular valve. The atriums were connected to a dominant right ventricle in 42, to a left ventricle in 29 and to a solitary indeterminate ventricle in 5. The most common atrial arrangement was isomerism of the right atrial appendages, seen in 46% (35/76). Of these, there was associated anomalous pulmonary venous connexion in 72% and absence of the spleen in 63%. Double outlet right ventricle was the most frequent ventriculoarterial connexion, present in 37 cases. Abnormal atrioventricular valvar function could already be detected in 46% of cases at the time of initial presentation. A decrease of function was observed in 18 patients, in 14 of them 2 weeks to 16 years (mean 5.7 years) after palliative surgery. The majority of the palliative procedures were constructions of shunts, since 75% (57/76) of the patients showed obstruction to flow of pulmonary blood. Patients with double inlet ventricle guarded by a common atrioventricular valve have a high early mortality (37% died in the neonatal period). Management should be designed to protect the integrity of the pulmonary vascular bed. Definitive repair with a Fontan type procedure is the most suitable final approach.