Abstract
Electrocardiographic studies were made on the 17 cases of ventricular septal defects before and after cardiac surgery.
The electrical axis and voltage of QRS complex were not altered significantly by surgery.
ST segments were elevated and T waves were inverted after surgery. The former returned towards normal level in a few weeks, however, the latter persisted for more than several months.
Nine out of 17 cases developed complete or incomplete right bundle branch block and showed widening of the QRS complex.
