Conditioned nutritional requirements and the pathogenesis and treatment of myocardial failure.

The majority of symptomatic patients with congestive heart failure have been shown to be significantly malnourished. Myocardial and skeletal muscle energy reserves are also diminished. Total daily energy expenditure in these patients is less than that in control individuals, and high protein-calorie feeds do not reverse the abnormalities; thus, the wasting that occurs in patients with congestive heart failure is metabolic rather than because of negative protein-calorie balance. Several specific deficiencies have been found in the failing myocardium: a reduction in the content of L-carnitine, coenzyme Q10, creatine and thiamine, nutrient cofactors that are important for myocardial energy production; a relative deficiency of taurine, an amino acid that is integral to the modulation of intracellular calcium levels; and an increase in myocardial oxidative stress, and a reduction of both endogenous and exogenous antioxidant defences. In addition, these processes may influence skeletal muscle metabolism and function. Cellular nutritional requirements conditioned by metabolic abnormalities in heart failure are important considerations in the pathogenesis of the skeletal and cardiac muscle dysfunction. A comprehensive restoration of adequate myocyte nutrition would seem to be essential to any therapeutic strategy designed to benefit patients suffering from this disease.