October 6, 1978

Cardiac Exercise Program

Author Affiliations

Torrance, Calif

JAMA. 1978;240(15):1588. doi:10.1001/jama.1978.03290150034014

To the Editor.—  The report "Ventricular Fibrillation in a Medically Supervised Cardiac Exercise Program: Clinical, Angiographic, and Surgical Correlations" by Fletcher and Cantwell (238:2627, 1977) brings out some pertinent information. It would be valuable to know the most important predictor of arrhythmia during exertion: the smoking history.Three of the five patients exercised in excess of their prescribed heart rates. The precise mode of exercise prescription was not given, although completion of a 1.6-km jog was mentioned for one of the subjects.This suggests that short bursts of anaerobic activity are being used. If these episodes of arrhythmia have occurred in smokers in oxygen debt, correction of these two factors should take precedence over bypass surgery.The study of Tilkian et al1 shows that "coronary surgery improves exercise capacity without decreasing associated ventricular arrhythmia." Three of the five patients had myocardial revascularization and were presumably able to continue the