Energy, structure, conformation, and heart failure

The problem of heart failure is analyzed from the point of view of conformation changes in submolecular cardiomyocyte structures. The development of heart failure as a consequence of abnormal function of contractile myocardial proteins is discussed. The properties of actin and the role of structural changes in actin molecules in the impairment of ATP energy utilization and generation of contractile force by actomyosin complexes are studied. Experiments on animal models and autopsy samples showed that conformation changes precede disturbances in energy utilization by myofibrils, abnormal functioning of the energy-producing and Ca^sup 2+^-transporting systems during the development of heart failure. It is proposed that rigid recombinations of submolecular structures in contracile proteins underlie impairment of myocardial contractility and resistance of the myocardium to regulatory factors and drugs (immobilization).[PUBLICATION ABSTRACT]