Characterization of cardiac dysfunction in sepsis: an ongoing challenge.

Sepsis-induced cardiomyopathy (SIC), which is a common morbid condition, occurs in patients with severe sepsis and septic shock. The clinical characterization of SIC has been largely concept-driven. Heart function has traditionally been evaluated according to two basic conceptual models: a hydraulic pump system, whereby the output from the heart is entirely dependent on its input, or a hemodynamic pump, whereby the cardiac output is a function of preload, global ventricular performance, and afterload. Minimal attention has been given to the intrinsic contractile function of the heart or to the interaction between the peripheral circulation and the intrinsic myocardial function in sepsis. Currently, SIC is assumed to be the result of the interaction of microorganisms that activate the physiopathological pathways and cellular signaling mechanisms that lead to intrinsic myocardial dysfunction. However, the animal models used to study SIC exhibit multiple limitations. This review addresses the conceptual background, historical perspectives, physiologic mechanisms, current evidence, and limitations of SIC characterization. It also highlights potential future directions for the hemodynamic assessment of the intrinsic contractile function of the heart to overcome current methodological limitations. Finally, the present review recommends the exploration of additional potential mechanisms underlying SIC.