THERAPY OF CARDIOGENIC-SHOCK AFTER MYOCAR DIAL-INFARCTION

Cardiogenic shock in acute myocardial infarction patients is the most common cause of in-hospital death. Various studies showed, that 60 to 100% of patients in cardiogenic shock will die, if no early reperfusio n of their coronary artery could be established. The incidence of card iogenic shock has decreased during the last years, most likely due to early thrombolytic therapy and administration of nitroglycerin. Reason s for cardiogenic shock are either necrosis of 40% or more of the left ventricular wall, right heart infarction, or complications which can be treated by the surgeon, like papillary muscle rupture, ventricular septal defect or rupture of the free ventricular wall. Diagnosis is ba sed on clinical criteria, echocardiography, and on hemodynamic monitor ing. The hemodynamic criteria for cardiogenic shock are a cardiac inde x of <2.2/I, and an increased wedge pressure of >18 mm Hg; additionall y, diuresis is usually <20 ml/h. Therapy can be divided into the follo wing categories: a) pharmaceutical interventions to increase cardiac o utput like vasodilators or positive inotrope drugs; b) mechanical supp ort systems; c) acute interventions with the aim of reperfusion; d) ac ute surgical interventions addressing complications like papillary mus cle rupture, ventricular septal defect and rupture of the free ventric ular wall. While steps a) and b) are able to stabilize the hemodynamic al situation in patients with cardiogenic shock, they are rarely the d efinitive treatment. Point c), reperfusion of the coronary artery, can be divided in thrombolysis or acute PTCA. Thrombolysis failed to show a beneficial effect in most studies, either after intravenous or intr acoronary application. On contrast, acute PTCA showed to be of great b enefit in various studies with a technical success rate of 54 to 100% and a survival rate of patients from 58 to 100%. Thus, emergency PTCA is the treatment of choice in cardiogenic shock. Point d), surgical in terventions can be divided in acute bypass grafting, which should be r eserved for patients with severe multivessel disease, left main involv ement, or failed PTCA. Furthermore, acute heart transplantation is eff ective, but will be possible in a minority of patients only. The last part of surgically manageable complications are surgery of papillary m uscle rupture and ventricular septal defect. Results of early surgery in papillary muscle rupture or ventricular septal defects are much bet ter than delayed interventions. Rupture of the free wall is usually a fatal event. In summary, the most successful therapy of cardiogenic sh ock is early emergency PTCA. In case of surgical treatable complicatio ns like papillary muscle rupture or ventricular septal defect, early i ntervention is also superior to the delayed approach after ''stabilizi ng'' of the patient.