Cardiac adaptations following exercise training in hemodialysis patients.

Patients with chronic renal failure (CRF) on hemodialysis (HD) are at increased risk of cardiovascular disease. This is due, mainly, to a higher prevalence of established arteriosclerotic risk factors, including diabetes mellitus, hypertension, dyslipidemia, physical inactivity, as well as to unique CRF-related risk factors. Accordingly, cardiorespiratory insufficiency, left ventricle dysfunction, atherosclerosis and cardiac sympathetic overestimation may often antedate, and hence contribute to exercise intolerance and to increased morbidity and mortality. In HD patients the application of exercise training programs is effective in improving cardiorespiratory capacity, as demonstrated mainly by the increasing of VO2peak. Moreover, better left ventricular systolic function at rest, as well as at effort following training was suggested. Indeed, the increase of cardiac vagal outflow and the decrease of sympathetic over-activity at rest are significantly beneficial results of exercise training in HD patients. However, whether these outcomes reduce the incidence of cardiac morbidity and mortality rate remains to be determined.