The Electrocardiogram and Ventricular Gradient in Isolated Congenital Pulmonary Stenosis

Abstract

The electrocardiogram and ventricular gradient were studied in 41 patients with isolated congenital pulmonary stenosis. The ventricular gradient was abnormal in 26 of the 41 patients (63 per cent). The  QRS migrated to the right in the frontal plane and  T migrated to the left. Following surgical reduction of the stenosis these vectors rotated rapidly toward the normal position. The electrocardiographic pattern in isolated congenital pulmonary stenosis tended to be of 4 types that were generally related to the right ventricular systolic pressure. The electrocardiographic changes associated with this defect, in which the work of the right ventricle was increased because of right ventricular hypertension, were different from those associated with atrial septal defect in which right ventricular work was increased because of high volume output. The duration of the QRS complex was not prolonged in the electrocardiograms of patients with pulmonary stenosis, whereas it was characteristically prolonged in those with atrial septal defect.