Cardiogenic Shock in the ER

Abstract

Cardiogenic shock (CS) is defined as clinical and biochemical manifestations of unsuccessful tissue perfusion due to ineffective cardiac output. It is the most common cause of mortality in patients with acute myocardial infarction, complicating 7–10% of cases (40,000–50,000) per year in the United States. Short-term mortality in cardiogenic shock in these patients is myocardial infarction (40–60%) and more than 80% when it is associated with ventricular septal rupture. Patients with high-clinical suspicion are those with hypotension (systolic blood pressure <90 mm Hg or vasopressors required to achieve a blood pressure >90 mm Hg), signs of impaired organ perfusion (confusion or lack of alertness, loss of consciousness, oliguria, and cold skin and extremities), and increased arterial lactate in the state of normovolemia or hypervolemia. Serial measurements of biomarkers of myocardial necrosis are useful to assess an early washout and to estimate the amount of cardiac necrosis. BNPB-type natriuretic peptide abnormal measurements are associated with acute heart failure progressing to CS and mortality. Noninvasive tests include chest, 12-lead ECG, and transthoracic echocardiogram. CS is a medical emergency and requires urgent evaluation and management. Understanding the underlying pathology will allow directed strategies to uncovering the cause. Inotropic agents enhance cardiac output and vascular tone in short to medium term in patients with CS. Mechanical support CS should be considered based on center expertise and availability and includes intra-aortic balloon pump, TandemHeart® Percutaneous Ventricular Assist Device (pVAD)™ system (Cardiac Assist, Inc.; Pittsburgh, PA), Impella (Abiomed, Danvers, MA), and extracorporeal membrane oxygenation.