Basic mechanisms of myocardial dysfunction: cellular pathophysiology of heart failure.

The cellular pathophysiology of myocardial dysfunction in heart failure is multifactorial. Studies of animal models and myocardium from patients with heart failure have demonstrated abnormalities of cytosolic calcium handling, myofilament calcium sensitivity, and myocyte energetics. Many of these metabolic abnormalities have been shown to be the result of alterations in the activity or number of myocyte enzymes and transport channels that are important in excitation-contraction coupling. Several innovative techniques for measuring intracellular calcium and energy metabolites and recent advances in cell biology have helped to further our understanding of the cellular pathophysiology of heart failure. Abnormalities at several levels of the excitation-contraction coupling mechanism have been shown to be responsible for both systolic and diastolic dysfunction in the failing heart.