Cardiogenic shock.

Cardiogenic shock is a complication of acute myocardial infarction characterized by reduction in systemic blood pressure and clinical evidence of impaired blood flow to the skin, central nervous system, and kidneys. Circulatory changes of cardiogenic shock result from excessive loss of contracting myocardium and impaired mechanical performance of the left ventricle. Hemodynamic measurements of left ventricular filling pressure (recorded as the pulmonary artery end-diastolic pressure) and the cardiac index can identify four different subgroups with hospital mortality ranging from 13 to 100 percent when managed with available pharmacologic agents. Patients in cardiogenic shock with a normal or near normal left ventricular filling pressure may respond to volume expansion by restoration of blood pressure and organ flow. The pharmacologic management of cardiogenic shock can be effectively enhanced by measuring the changes in cardiac index and left ventricular filling pressure before and after various vasopressor, inotropic, and volume expansion agents. A clinical scheme for the management of cardiogenic shock based on hemodynamic measurements delineates optimal medical management as well as recognition of rupture of the ventricular septum or the papillary muscle. Despite the combined medical and surgical advances in cardiogenic shock, hospital mortality remains high due to the extensive loss of contracting myocardium of the left ventricle.