The effect of coronary revascularization on exercise-induced ventricular arrhythmias.

From the data available so far it is apparent that in patients with stable angina, bypass graft surgery is not associated with any change in ventricular premature complexes or complex ventricular arrhythmias at rest or during exercise over a 1-5 year follow-up period despite the evidence of a substantial relief of exercise-induced ischaemia persisting for 5 years. In addition, ventricular arrhythmias are not predictive of sudden death except in a few patients, in whom ventricular tachycardia or ventricular fibrillation during exercise-induced ischaemia could be documented. Such exercise-induced arrhythmias appear to have a poor prognosis, unless the ischaemia is relieved by bypass surgery. The available literature suggests that ventricular arrhythmias at rest or during exercise in patients following bypass surgery are not related to ischaemia but to other unknown factors. Electrical instability during exercise may be caused by other factors rather than by ischaemia, and this phenomenon should be further investigated.