Studies on the QRS wave of the spatial magnitude electrocardiogram in ventricular septal defect

The QRS wave of the spatial magnitude electrocardiogram (ECG) was investigated in 86 cases of the ventricular septal defect (VSD). The relationship between the amplitude and the time interval of QRS wave of the spatial magnitude ECG and the various hemodynamic parameters obtained by the right heart catheterization and the defect area ascertained during the operations were evaluated.