Myocardial Changes Associated with Cardiogenic Shock

The amount of left ventricular myocardium destroyed by recent and old infarcts in patients with acute myocardial infarction with and without cardiogenic shock was compared in hearts obtained at autopsy. All 20 patients with, and only one of 14 without, shock had lost 40 per cent or more of the left ventricle. The remainder lost 35 per cent or less. These results indicate that cardiogenic shock is associated with extensive loss of left ventricular myocardium due to new and frequently old infarcts as well. In five cases the new infarct was small as compared to the total amount of myocardial destruction. Patients with cardiogenic shock consistently showed marginal extension of the recent infarct (unlike those not in shock) and focal areas of necrosis throughout both left and right ventricles. Similar focal lesions were encountered in a third series of 20 patients with shock from other causes. A sharp reduction in coronary perfusion pressure could explain this combination of findings, which indicate that cardiogenic shock is a continuous, self-perpetuating, vicious circle leading to progressive, irreversible myocardial dysfunction.