ABSTRACT
OBJECTIVE: To evaluate the effects of an exercise training programme on patients with chronic left ventricular dysfunction. DESIGN: Intervention, before and after the trial. SETTING: Johannesburg Cardiac Rehabilitation Centre, a phase III community-based cardiac rehabilitation facility. PATIENTS: A consecutive sample of 28 patients who were recovering from acute myocardial infarction and who had a left ventricular ejection fraction of 30% or less. Twenty two patients completed the exercise training programme. INTERVENTION: A medically supervised exercise training programme of 6 months' duration. Type of exercise: walking, jogging or cycling. Intensity: 65-85% of the patient's maximal heart rate achieved during treadmill testing. DURATION: 30-45 minutes. Frequency: 3 times a week. Patients who attended fewer than 60% of all prescribed sessions were considered drop-outs. MAIN OUTCOME MEASURES: Haemodynamic, left ventricular function and effort tolerance parameters before and after training. RESULTS: Patients who completed the exercise training programme showed a significant improvement in maximal exercise capacity and a significant reduction in their cardiovascular demands during submaximal exercise. Peak oxygen consumption was increased by 12% after training (19.4 +/- 3 v. 21.8 +/- 4.8 ml/kg/min; P < 0.05) and exercise time to exhaustion by 33% (527 +/- 171 v. 700 +/- 186 seconds; P < 0.001). The double product at the same submaximal workload was significantly reduced (214 +/- 52 v. 194 +/- 44 beats/min x mmHg x 10(2); P < 0.05). These benefits were achieved without any adverse effects on resting (25.4 +/- 5 v. 28.5 +/- 7.9%; P < 0.05) or exercise (27.3 +/- 7.7 v. 29.9 +/- 9.5%; P > 0.05) left ventricular ejection fraction. CONCLUSIONS: Our results show that patients with chronic left ventricular dysfunction can benefit from an exercise training programme and that those benefits can be achieved without risk of further deterioration in left ventricular function. Physical training constitutes another therapeutic option which could be added to the comprehensive management of these patients.
