Cardiorespiratory effects of warm water immersion in elderly patients with chronic heart failure

BACKGROUND: Hydrotherapy might be included in the rehabilitation of patients with chronic heart failure (CHF), but little is known about the acute cardiorespiratory reaction in warm water. The aim of this study was to assess the acute cardiorespiratory effect of immersion in warm water, in a clinical setting, in elderly patients with CHF compared with healthy age and sex matched persons. METHODS: Twelve patients (three females) with CHF, NYHA II-III, age 64 +/- 6 years, and 12 healthy subjects were studied. Cardiorespiratory changes, on land and in a temperature-controlled swimming pool (33-34 degrees C) were assessed during rest and exercise, in a sitting position, using continuous gas analyses. RESULTS: There were no significant differences, land versus water, in carbon dioxide production, total ventilation, respiratory frequency, respiratory exchange ratio, heart rate or blood pressure in either of the groups. A significant difference was found in oxygen uptake, at rest, land versus water in patients with CHF in comparison with healthy subjects (-0.2 +/- 0.4 versus +0.3 +/- 0.6 ml kg(-1) min(-1), P < 0.01). Oxygen kinetics (tau) increased significantly (P = 0.01) in both groups during exercise in water. CONCLUSION: Hydrotherapy was well tolerated and the vast majority of the cardiorespiratory responses, during warm water immersion in a clinical setting, are similar in patients with CHF compared with healthy subjects. However, further larger studies, are needed to better understand the physiological reactions during hydrotherapy.