Effects of supine ergometer exercise on central and peripheral circulation in patients with ischemic heart disease

[Purpose] To clarify the characteristics and safety of circulatory dynamics during supine ergometer exercise in patients with cardiac disease by examining autonomic nervous system activity and lower limb blood flow, and to compare these responses with those observed during seated ergometer exercise. [Participants and Methods] Ten patients with ischemic heart disease performed ergometer exercises in two positions, supine and seated at the anaerobic threshold level intensity. Measurements included lower limb blood flow, autonomic nervous activity, physiological indicators, and perceived exertion at rest and during warm-up, main exercise, and cool-down. [Results] The Sup Ex condition exhibited significantly higher lower limb blood flow and parasympathetic activity than the Sit Ex condition. No significant differences were observed in sympathetic nervous system activity, heart rate, systolic blood pressure, or double product. The heart rate, systolic blood pressure, and double product increased during exercise and decreased during cool-down, along with increased parasympathetic activity. Borg scale scores for leg and dyspnea increased over time but did not differ significantly between positions. [Conclusion] Despite similar cardiac loads and perceived exertion, the supine ergometer exercise resulted in greater parasympathetic activation and lower limb blood flow, suggesting its potential safety and benefits in the rehabilitation of patients with ischemic heart disease.