Electrocardiographic diagnosis of malformations associated with tricuspid atresia: Correlation with morphologic features

Abstract

The electrocardiographic findings in 31 cases of tricuspid atresia were reviewed. Electrocardiographic differentiation of the types of tricuspid atresia was possible to some extent, but vectorial analysis of the scalar ECG's suggests that the vectorcardiogram provides the best and easiest differentiation among the anatomic types of tricuspid atresia. Patients with transposition of the great vessels (type II) tended to have no left axis deviation (as previously reported) and a clockwise rotation of the vector loop in the frontal plane. In the precordial ECG's, left ventricular hypertrophy based on voltage criteria was absent when the great vessels were transposed. Vectorial analysis of precordial scalar ECG's showed that patients without pulmonary stenosis or atresia tended to have wide horizontal vector loops with display of anterior forces and those with pulmonary stenosis frequently had narrow horizontal loops which were oriented posteriorly. Repolarization abnormalities such as inverted or biphasic T waves in V 6 were present only in patients with increased pulmonary flow. The electrocardiographic features observed with various associated malformations of tricuspid atresia appeared to be related to the morphologic findings in these malformations.