Electro-vectorcardiographic features of double-chambered right ventricle

Twelve patients with double-chambered right ventricles wereinvestigated to determine the significance of the electrocardiogramand vectorcardiogram in the evaluation of this condition. Twosubgroups of individuals having various forms of obstructionto right ventricular outflow with and without intracardiac shuntingwere utilized as controls. The electrocardiogram of patientswith double-chambered right ventricle had a characteristic appearanceidentifiable as a right ventricular hypertrophy pattern seenbest in the extreme right precordial leads V₄R–V₃R withtendency to normalization of pattern in V₁, which contrastedwith the pattern in both control subgroups. The vectorcardiogramin all 8 cases of double-chambered right ventricle in whichthis study was performed exhibited homogeneity of loop appearanceand direction best identifiable in the horizontal plane by aprominent terminal orientation of the loop rightward and posteriorly.Both control subgroups exhibited heterogeneity of loop conformation,significantly more initial right-anterior force and less rightposteriorforce than the double-chambered right ventricle group. The electro-vectorcardiographicfindings with double-chambered right ventricle were predictablefor this abnormality and appear to have significant diagnosticimportance.