Exercise training in patients with left ventricular systolic or diastolic dysfunction: Harmful or helpful?

Left ventricular systolic (SD) and diastolic (DD) dysfunction cause a reduction in cardiac output that results in a variety of pathophysiologic adaptations and ultimately the "syndrome" of congestive heart failure (CHF). The incidence of CHF is increasing, and this condition carries a high mortality and places a considerable financial burden on the health care system. Treatment options for CHF include several surgical procedures, optimal pharmacotherapy, and lifestyle modification. Exercise training, though beneficial for many patient populations, may be contraindicated in patients with CHF for fear of further deterioration or left ventricular function. In fact, despite the use of different experimental models, two studies concluded that exercise training after large myocardial infarctions resulted in further deterioration of left ventricular function and a reduction in survival. In contrast, a number of studies dating from the late 1980s to the present have shown that moderate exercise training (30-40 min three to five times per week at 50%-70% of peak effort) did not cause undesirable left ventricular "remodeling." Moreover, exercise training in patients with CHF appears to result in a number of beneficial peripheral adaptations. One study showed that exercise training reduced mortality in CHF patients due to SD. Although less is know about DD, preliminary work from our laboratory suggests that these patients also have favorable outcomes after exercise training. The current consensus is that exercise training for patients with stable CHF due to either SD or DD is helpful, not harmful.