Heart rate response to graded exercise correlates with aerobic and ventilatory capacity in patients with heart failure
| Autor: | Sandro Orlandi, Guido Gigli, Giorgio Reggiardo, Alessandro Vallebona |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Chronotropic
endocrine system medicine.medical_specialty Ejection fraction Heart disease business.industry Case-control study Physical exercise General Medicine medicine.disease Endocrinology Heart failure Internal medicine Heart rate medicine Cardiology Exercise physiology Cardiology and Cardiovascular Medicine business human activities circulatory and respiratory physiology |
| Zdroj: | Clinical Cardiology. 28:25-29 |
| ISSN: | 0160-9289 |
| Popis: | Background: Autonomic dysfunction and reduced exercise tolerance are typical features of patients with congestive heart failure (CHF). Baro-chemoreflex balance and organ response may have a common role in conditioning exercise tolerance, ventilation, and chronotropic competence in patients with CHF. Hypothesis: We tested the hypothesis that there is a relationship between functional capacity and chronotropic competence to exercise in CHF. Methods: In all, 48 stable outpatients with CHF (age 65 ± 10 years, 41 men, NYHA class 2.1 ± 0, ejection fraction 31 ± 7%, peak VO2 16 ± 4 ml/kg/min) performed cardiopulmonary exercise testing (CPX). Heart rate (HR) response to exercise was assessed by the chronotropic index (CRI). The CRI was calculated by the following formula: CRI = peak HR - rest HR/220 - age - rest HR × 100 (normal value > 80%). The relationship of CRI to peak oxygen consumption (VO2) and ventilation/carbon dioxide production (VE/VCO2) ratio was examined. A group of 33 healthy controls underwent CPX as well. Results: The CRI correlated directly with peak VO2 (r = 0.638, p 30, 95% CI 0.53–0.88). The CRI was not significantly related either to peak VO2 or to VE/VCO2 in the control group. Conclusions: In patients with mild to moderate CHF, CRI correlates with functional capacity. This relationship adds new data on pathophysiologic grounds and supports the routine incorporation of CRI into CPX interpretation. |
| Databáze: | OpenAIRE |
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