Cardiac Autonomic Nervous System and Sepsis-Induced Cardiac Dysfunction

Abstract

Cardiac dysfunction is one of the main predictors of poor prognosis in septic patients. Although it has been investigated for more than 30 years, the mechanisms for sepsis-induced cardiac dysfunction are not completely understood, and no specific, effective treatment exists. Traditionally, sepsis-induced cardiac dysfunction was defined as a reversible decrease in ejection fraction of both ventricles with ventricular dilation and depressed response to fluid resuscitation and catecholamines. Many studies have demonstrated that autonomic nervous system imbalance, characterized by sympathetic overactivation and vagal suppression, contributes to the pathogenesis of sepsis-induced cardiac dysfunction. Thus, this kind of cardiac dysfunction can perhaps be best described as a sepsis-induced cardiac autonomic dysfunction as well as an intrinsic systolic and diastolic dysfunction of the whole heart, which is characterized by tachycardia, strongly decreased heart rate variability, and depressed intrinsic systolic and diastolic function of both ventricles. This review will summarize our current knowledge of sepsis-induced cardiac dysfunction, with a special focus on the role of autonomic dysfunction.