Abstract

In order to know the value of a peculiar right ventricular repolarization in the diagnosis of atrial septal defect. We studied-one hundred patients with main right bundle branch block and atrial septal defect confirmed by cardiac catheterization. The peculiar right ventricular repolarization consist in a straight and long S-T segment (longer than 160 msc) that form a 60 degrees or greater angle with the ascendent branch of the T wave. This electrocardiographic sign was found in 82 patients (sensitivity 82%). There were no differences between the age groups or the pulmonary pressure levels. In sixty five patients with main right bundle branch block without atrial septal defect, this peculiar right ventricular repolarization was investigated. It was found in fourteen cases (specificity 78.4%). Positive predictive value was 85.4%, negative predictive value 73.9% and diagnostic efficiency 80.6%. When the atrial septal defect was repaired (76 patients), the peculiar right ventricular repolarization disappeared in 87.7% of the cases (p less than 0.0001). It can be concluded that the peculiar right ventricular repolarization, in presence of main bundle branch block supports the diagnosis of atrial septal defect.