Post-Exercise Neurovascular Control in Chronic Heart Failure Patients

Abstract

It remains unknown whether or not a reduction in muscle sympathetic nerve activity in heart failure patients is associated over time with the effects of long- or short-term repeated exercise. 10 chronic heart failure patients, age 49±3 years old, functional class I-III NYHA, ejection fraction <40% were randomly submitted to either an acute bout of moderate continuous exercise OR high-intensity interval exercise. Muscle sympathetic nerve activity (microneurography) and forearm blood flow (venous occlusion plethysmography) were evaluated pre- and post-exercise sessions. The moderate exercise consisted of cycle exercise at an intensity corresponding to anaerobic threshold. The interval exercise consisted of a 2-min cycle exercise at intensity corresponding to anaerobic threshold, followed by a 1-min exercise set at respiratory compensation point. Exercise capacity was evaluated by cardiopulmonary exercise test. The caloric expenditure in both sessions was 100 kcal. Baseline muscle sympathetic nerve activity and forearm blood flow levels were not different between sessions. Moderate or high-intensity exercise caused no significant changes in muscle sympathetic nerve activity and forearm blood flow. These findings suggest that the reduction in muscle sympathetic nerve activity and the increase in forearm blood flow provoked by exercise training in chronic heart failure patients are due to cumulative effects over time.

Physical function and exercise training in older patients with heart failure

“…The changes in skeletal muscle function in older patients with HF have been shown to exaggerate reflex sympathoexcitation via muscle ergoreceptor overactivity, and this feature might worsen the severity of HF through its effects on persistent neurohormonal overactivity. Physical exercise training of the altered HF skeletal muscle has been shown to reduce this reflex sympathoexcitation at least partially 19 . Another feature of the elderly HF phenotype associated with exercise intolerance is impaired endothelial function; exercise training has been shown to correct this dysfunction more effec tively in older than in younger patients with HF, through an increase in endothelial progenitor cells 20 .…”