Mechanical Circulatory Support

Abstract

In other chapters, there are detailed discussions of acute decompensated heart failure (Chap. 19) and shock (Chap. 21). Cardiogenic shock (CS) represents a state in which cardiac dysfunction is either wholly or partially responsible for an inadequate level of cardiac output to support end-organ function. CS is an especially dangerous state, with in-hospital mortality as high as 27–51% (van Diepen et al., Circulation. 136:e232–68, 2017). Therefore, interventions that promptly reverse the pathophysiologic process are critical. While CS can result from a variety of etiologies – acute myocardial infarction (AMI), acute valvular regurgitation, decompensated heart failure, ventricular tachycardic storm, or myocarditis, to name just a few – once the insult triggers primary dysfunction, the nature of CS is a downward spiral of consequences ultimately resulting in multi-organ failure and death. Even if myocardial ischemia is not the primary cause of cardiac dysfunction, a drop in cardiac output and coronary perfusion pressure during CS nonetheless leads to ischemia and further systolic and diastolic dysfunction, both of which precipitate a feedback loop of progressive dysfunction. This chapter focuses on the use of mechanical circulatory support (MCS) to intervene in the early stages of this cycle.