Evaluating presynaptic and postsynaptic innervation in heart failure.

Congestive heart failure increasingly contributes to the overall morbidity and mortality associated with cardiovascular disease. Although significant advances in therapies allow patients to feel better and have improved functional status and survival, not all patients respond equally to these therapies. Moreover, for any given level of left ventricular systolic dysfunction, it is difficult to predict who will have progressive heart failure leading to death or transplantation or who will die suddenly. It has long been recognized that the sympathetic nervous system plays a major role in the morbidity and mortality associated with congestive heart failure from systolic left ventricular dysfunction. Although some of the sympathetic effect occurs at the systemic level, malfunction at the ventricular myocyte-sympathetic nerve terminal interface is likely a major contributor to sudden death and progressive heart failure. Imaging the cardiac sympathetic nervous system can be used to evaluate this myoneural interface and to predict outcome.