. In cardiac shock

Cardiogenic shock (CS) is characterized by systemic hypoperfusion due to severe depression of the cardiac index and sustained systolic aerial hypotension (<90 mmHg) despite an elevated filling pressure . It is associated with in-hospital moality rates >50%. . Circulatory failure based on cardiac dysfunction may be caused by primary myocardial failure, most commonly secondary to acute myocardial infarction(MI) , and less frequently by cardiomyopathy or myocarditis , cardiac tamponade, or critical valvular hea disease Systolic and diastolic myocardial dysfunction results in a reduction in cardiac output and often pulmonary congestion. Systemic and coronary hypoperfusion occur, resulting in progressive ischemia. Although a number of compensatory mechanisms are activated in an attempt to suppo the circulation, these compensatory mechanisms may become maladaptive and produce a worsening of hemodynamics. *Release of inflammatory cytokines after myocardial infarction may lead to inducible nitric oxide expression, excess nitric oxide, and inappropriate vasodilation. This causes fuher reduction in systemic and coronary perfusion. A vicious spiral of progressive myocardial dysfunction occurs that ultimately results in death if it is not interrupted. LVEDP, left ventricular end-diastolic pressure ref:harrison&;s principles of internal medicine,ed 18,pg no 2232