Central adaptations to exercise training in patients with chronic heart failure.

In chronic heart failure patients, the increase of peak VO(2)observed after a period of aerobic training is currently attributed more to peripheral (skeletal muscle) than central (heart) adaptations. This paper reviews the current scientific evidence regarding the existence or the absence of significant training-induced adaptations of peak cardiac output and its determinants in patients with chronic heart failure due to left ventricular systolic dysfunction. It is concluded that, on the basis of available literature, a training-induced significant increase of peak cardiac output with respect to pre-training values does exist in the chronic heart failure population. Such an effect is due to adaptations of the main cardiac output determinants, that is, heart rate and stroke volume, whose relative contribution to the cardiac output increase will vary in the single patient due to variability in the individual response to the training stimulus. Moreover, these data emphasize both the safety and even the central morpho-functional benefits of aerobic training programs in the chronic heart failure population, setting the stage for an even more widespread use of this non-pharmacologic intervention in the everyday clinical practice. As most studies considered in this review were conducted in the pre-beta-blockers era, the possibility to extend the conclusions of this paper to chronic heart failure patients on beta-blocking therapy remains to be verified.