Electro-vectorcardiographic features of double-chambered right ventricle

Twelve patients with double-chambered right ventricles were investigated to determine the significance of the electrocardiogram and vectorcardiogram in the evaluation of this condition. Two subgroups of individuals having various forms of obstruction to right ventricular outflow with and without intracardiac shunting were utilized as controls. The electrocardiogram of patients with double-chambered right ventricle had a characteristic appearance identifiable as a right ventricular hypertrophy pattern seen best in the extreme right precordial leads V4R-V3R with tendency to normalization of pattern in V1 which contrasted with the pattern in both control subgroups. The vectorcardiogram in all 8 cases of double-chambered right ventricle in which this study was performed exhibited homogeneity of loop appearance and direction best identifiable in the horizontal plane by a prominent terminal orientation of the loop rightward and posteriorly. Both control subgroups exhibited heterogeneity of loop conformation, significantly more initial right-anterior force and less right-posterior force than the double-chambered right ventricle group. The electro-vectorcardiographic findings with double-chambered right ventricle were predictable for this abnormality and appear to have significant diagnostic importance.