Resistance exercise in chronic heart failure: hemodynamic and metabolic adjustments

The aim of this study was to characterize hemodynamic and metabolic responses to dynamic resistance exercise in chronic heart failure patients (CHF) compared to healthy older men (CTR). We hypothesized that in controlled conditions; pharmacologically treated CHF should show the adaptations to the strength exercises similar to healthy subjects, demonstrating therefore the compatibility with the practical on field. We addressed the acute effects of dynamic resistance exercise in eight CHF patients and eleven age-matched CTRs, instrumented for expiratory gas and cardiovascular analysis. All subjects performed two series with up to twelve repetitions at 70 % of 1RM on a leg press machine. Arterial pressure and heart rate progressively increased throughout the movements and decreased on cessation, while stroke volume (Modelflow software) decreased by 30 % at the start and increased by 10 % at cessation. Cardiac output increased at cessation only. All values were lower in CHF, but the changes during the exercises were not significantly different from those of CTR. Oxygen consumption increased during the exercises and continued increasing thereafter up to 60–70 % V’O2max (absolute changes were smaller in CHF). We concluded that the response to dynamic resistance exercise is characterized by a sharp hindrance to the output of blood from the heart, which reduces stroke volume and enhances arterial pressure in CHF as well as in CTR. The simultaneous increase in heart rate kept cardiac output unaltered. The most important differences concerned a reduced metabolic response during exercise in CHF, even more evident in rest. Chronic heart failure syndrome and its treatment do not interfere with the cardiovascular responses to these kinds of physical activities. This finding can be considered a step forward in demonstrating that patients with chronic heart failure can, in controlled conditions, safely practice these essential exercises to preserve their muscle integrity. © 2016, Springer-Verlag Italia.