Exercise training and myocardial energetics in patients with heart failure: when more is less.

eart failure is the major cause of morbidity and mortality n the developed world, with over 5 million people afflicted n the U.S. alone (1). From 30% to 40% of patients die ithin the first year after receiving the diagnosis of heart ailure (1). Further, heart failure consumes a significant mount of resources, and this is only likely to increase as the opulation ages. Consequently, the development of theraeutic strategies to improve outcomes and slow or halt the rogression of heart failure is a major goal of clinical cardioascular investigation. Development of successful therapeutic trategies is predicated on a clear understanding of the pathohysiology of heart failure. Although heart failure is a diverse roup of diseases with numerous etiologies, one common