Role of exercise and metabolism in heart failure with normal ejection fraction

Left ventricular dysfunction associated with metabolic disorders has a number of features that might shed light on the integrity of heart failure with normal ejection fraction. First, although these patients may be dyspneic and have a normal ejection fraction, their diastolic dysfunction is not isolated. Both experimental models and sensitive new parameters in humans have shown abnormal systolic function, even though the less sensitive parameters (such as ejection fraction) become abnormal only with stress. Moreover, the mechanistic contributors to myocardial dysfunction, including structural changes and metabolic influences on the cardiac myocyte, interstitial fibrosis, vascular disease, and altered loading, are likely to influence systolic as much as diastolic function. The responses of systolic and diastolic heart failure to exercise training show analogies, particularly with respect to the importance of peripheral adaptation, as well as a similar training response. Together, these features are more supportive of a continuum of pathophysiology between systolic and diastolic heart failure, rather than the 2 representing discreet phenomena.