The Ergoreflex in patients with chronic stable heart failure

Background: The main symptoms of chronic heart failure are breathlessness a nd fatigue on exertion. Abnormalities of skeletal muscle cause early metabo lic distress on exercise, with resultant ergoreceptor stimulation causing i ncreased ventilation. The aim of this study is to determine the extent of e nhanced ergoreflex activity in chronic heart failure in the leg. Methods: T en patients with chronic stable heart failure (New York Heart Association c lass II-III) and nine healthy age-matched controls performed two bouts of a nkle dorsiflexion. On one occasion a cuff was inflated round the thigh to s uprasystolic levels for 3 min immediately post-exercise: regional circulato ry occlusion. Recovery with regional circulatory occlusion was compared to recovery without it. Results: Systolic and diastolic blood pressure and ven tilation were higher after 3 min post-exercise regional circulatory occlusi on than after 3 min control recovery in the patient group (184+/-13.3 vs 16 5+/-12.5 mmHg, P<0.01, 94+/-4.7 vs 86+/-3.5 mmHg, P<0.05, 9.8+/-0.7 vs 7.9- 1-0.36 1/min, P<0.01). Systolic and diastolic blood pressure were higher af ter post-exercise regional circulatory occlusion than after control recover y in the control group (149+/-7.8 vs 138+/-5.7 mmHg, P<0.01, 86+/-3.3 vs 82 +/-2.5 mmHg, P<0.05), but this was not the case for ventilation (8.1+/-0.62 vs 8.1+/-0.62 1/min). Ergoreflex activity was greater in the patient group than in the controls for systolic blood pressure (91 vs 48%, P<0.001), dia stolic blood pressure (86 vs 49%, P<0.05) and ventilation (39 vs -1%, P<0.0 5), Conclusions: Ergoreceptor stimulation contributes to an increased venti lation and blood pressure response to leg exercise in chronic heart failure patients, perhaps contributing to dyspnoea and exercise limitation. Periph eral factors such as skeletal muscle abnormalities contribute to the pathog enesis of symptoms in chronic heart failure. (C) 1999 Elsevier Science Irel and Ltd. All rights reserved.