Factors affecting mortality in Ebstein's anomaly of the tricuspid valve.

Ebstein's anomaly of the tricuspid valve is a relatively uncommon congenital heart defect. Twenty-one patients (11 boys and 10 girls) with Ebstein's anomaly were reviewed regarding clinical characteristics and factors related to the outcome of this lesion. Their ages at presentation ranged from 1 day to 13 years (median = 11 months). Eleven patients presented in infancy period, 6 of them were neonates. Common clinical findings were systolic murmur (85.7%) and cyanosis (57.1%). Laboratory findings included cardiomegaly on chest X-rays (95.2%), right bundle branch block pattern (76.2%) and right atrial enlargement (61.9%) on electrocardiography. Diagnosis and grading of severity were established by echocardiography. Among 21 patients, 4 were lost during follow-up. Seventeen patients were followed for 3-72 months. Six patients (28.6%) required surgery, 5 of whom died following surgery. Two patients died during the medical follow-up. Factors affecting cardiac death were the younger age at presentation, onset of cyanosis in infancy period, associated PS or PA, the lower insertion of the septal leaflet of the tricuspid valve and the higher ratio of the combined area of right atrium and atrialized right ventricle to that of functional right ventricle and left heart chambers.