Unexpected cardiac arrest in patients after surgical correction of tetralogy of Fallot

Abstract

Four of 220 patients without bifascicular block (complete right bundle branch block and left anterior hemiblock or transient complete heart block immediately) after surgery had an unexpected cardiac arrest one to 15 years after satisfactory surgical repair of tetralogy of Fallot. The postoperative electrocardiograms (ECG) revealed complete right bundle branch block in two patients and no intraventricular conduction abnormality in two patients. Each of the four patients had premature ventricular contractions on previous postoperative ECG. The cardiac arrest occurred during normal activity in three patients and mild exercise in one. Following the cardiac arrest, three patients died and one patient survived. Eighteen months before the cardiac arrest, the survivor had a stress test which revealed multifocal premature ventricular contractions with short bursts of ventricular tachycardia after exercise. This ventricular arrhythmia was suppressed with quinidine therapy. Although complete heart block cannot be excluded in these four patients, the authors reasoned that the cardiac arrests were probably preceded by ventricular tachyarrhytmia. Because of this experience, we believe that any patient who has had intraventricular surgery should be evaluated for ventricular arrhytmia. If frequent premature ventricular contractions or serious ventricular arrhytmias are documented, we seriously consider antiarrhytmic therapy in an attempt to prevent ventricular tachyarrhytmias and sudden death.