Abstract

The effect of propanolol on cardiac patients undergoing exercise training is reported to increase exercise tolerance and maximum oxygen uptake (VO2 max) but its effect on anaerobic threshold (AT) is unknown. It was the purpose of this study to determine the role of exercise training with propanolol on AT in patients with coronary artery disease (CAD). Eight men and one woman with significant (CAD) completed a maximum treadmill stress test (MTST) following the Bruce protocol on propanolol 40-160 mg/day as a control study. Cardiorespiratory variables were measured at rest and at each stage of the treadmill test. These patients underwent an exercise training programme for 12-16 weeks on the same dose of propanolol. Training sessions were for a minimum of 30-40 minutes, 3 times a week. Training heart rate ranged from 98 to 128 beats/min. They were retested with a MTST after the training programme, on the same dose of propanolol. AT was identified by measuring the time course of VE, VCO2, VE/VO2, etc. in relation to incremental work. After exercise training on propanolol, the mean peak exercise tolerance time and absolute VO2 max increased by 2.8 min (from 9.0 to 11.8 min) and 22.7, respectively. We conclude that the increase in anaerobic threshold in patients with coronary artery disease may be due to improvement in VO2 max, increased stroke volume, and peripheral O2 extraction. Verf.-Referat