Abstract
Arrhythmias have been recorded in association with congenital pulmonary stenosis. Of six patients who had arrhythmias before operation, anatomical conduction defects were present in two and the arrhythmias persisted after operation. In four, the arrhythmic episodes have not been recorded after operation. No specific causative factors were evident in the pre-operative group. Acute and often fatal arrhythmias have occurred in the early post-operative period. High risk patients were those with cyanosis, high right ventricular pressure (in excess of 175 mm. Hg), and gross right ventricular hypertrophy. There is evidence to suggest that these arrhythmias develop in association with myocardial ischaemia.