[Semi-supervised exercise using a step machine at home after myocardial infarction]

Home exercise programs for patients with myocardial infarction effectively improve their ability to exercise as well as quality of life. However, there are no efficient methods for monitoring the patient's clinical status or conveying the physician's instructions to the home setting. To resolve these problems, we developed a computer-based, automated, telemetry system comprised of central and peripheral computers and telephone line. Five myocardial infarction patients were evaluated for peak oxygen uptake (peak VO2) and anaerobic threshold (AT) before hospital discharge. At home, the patients performed 10-min exercise using a step machine. Patient data including blood pressure, pulse rate, and electrocardiogram before and after exercise were stored in the peripheral computer, and the central computer automatically retrieved the data through the phone line. If the current heart rate was less than the heart rate at AT, extreme changes in blood pressure were noted or dangerous arrhythmias appeared, appropriate instructions were indicated on the display of the peripheral computer. Following these instructions, the patients continued home exercise programs for 6 months. Peak VO2 and AT increased significantly in all patients (peak VO2: baseline 24 +/- 3.3 ml/kg/min, 6 months later 33.3 +/- 3.7 ml/kg/min, p < 0.01, AT: baseline 15.2 +/- 2.7 ml/kg/min, 6 months later 18.5 +/- 2.8 ml/kg/min, p < 0.01). The computer-based automated telemetry system combined with a step machine facilitated effective prescription and monitoring of exercise programs at home.