Immersion in warm water induces improvement in cardiac function in patients with chronic heart failure

The effects of immersion and training of patients with chronic heart failure (CHF) in warm water has not been thoroughly investigated. The aim of this study was to assess the acute hemodynamic response of immersion and peripheral muscle training in elderly patients with CHF.

Thirteen CHF patients and 13 healthy subjects underwent echocardiography on land and in a temperature-controlled swimming pool (33-34 degrees C).

Rest. Heart rate decreased (CHF, p=0.01; control, p=0.001) and stroke volume increased (CHF, p=0.01; control, p=0.001) during water immersion in both groups, with no change in systolic or diastolic blood pressure. Ejection fraction (p<0.05) and transmitral Doppler E/A ratio (p=0.01) increased in the CHF group, with no changes in left ventricular volumes. The healthy subjects had similar responses, but also displayed an increase in cardiac output (p<0.01) and left ventricular volumes (p<0.001). Exercise. Cardiac output and systolic blood pressure increased significantly in water, in both groups.

A general increase in early diastolic filling was accompanied by a decrease in heart rate, leading to an increase in stroke volume and ejection fraction in most patients with CHF during warm water immersion. These beneficial hemodynamic effects might be the reason for the previously observed good tolerability of this exercise regime.