Characterization of Cardiac Dysfunction in Sepsis

Abstract

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.

Experimental Evidence of Bacterial Colonization of Human Coronary Microvasculature and Myocardial Tissue during Meningococcemia

“…Diverse mechanisms underlying septic myocardial depression have been described previously (21,22). Sepsis-induced cardiomyopathy appears to be an excessive physiological adaptation of the heart function to the sepsis and not a myocardial tissue injury.…”

Herz in der Sepsis

“…Tab. 1) inderFrühphase derseptischen Kardiomyopathie [111]. In einer klinischen Observationsstudie untersuchten Landesberg et al den Zusammenhang zwischen diversen im Serum vorhandenen pro-und antiinflammatorischen Zytokinen (IL-1β, IL-6, IL-8, IL-10, IL-18, TNF-α) und der kardialen Funktion bei 105 Patienten mit schwerer Sepsis und septischem Schock [57].…”

Improved Survival in a Long-Term Rat Model of Sepsis Is Associated With Reduced Mitochondrial Calcium Uptake Despite Increased Energetic Demand

“…Myocardial depression is a well-recognized phenomenon in patients with septic shock with reported incidence rates of 40-50% (1,2). The underlying pathophysiology is complex with multiple factors implicated (3,4).…”

“…Studies using more clinically relevant models of polymicrobial sepsis report variable degrees of myocardial and mitochondrial dysfunction, often with unchanged levels of phosphate intermediates (13)(14)(15). Myocardial dysfunction in sepsis may be the result of a hibernation-like state, whereby cardiomyocytes decrease mitochondrial oxygen consumption under conditions of lower cellular metabolic demand (2,3). However, this notion remains to be confirmed as most studies have only used steady state measures of mitochondrial function, rather than capturing the interaction between energy supply and demand.…”