RT Book, Section A1 Tomey, Matthew I. A1 Gidwani, Umesh K. A2 Oropello, John M. A2 Pastores, Stephen M. A2 Kvetan, Vladimir SR Print(0) ID 1136414212 T1 Acute Cardiac Ischemia T2 Critical Care YR 1 FD 1 PB McGraw-Hill Education PP New York, NY SN 9780071820813 LK accessmedicine.mhmedical.com/content.aspx?aid=1136414212 RD 2024/03/28 AB KEY POINTSAny acute imbalance between myocardial oxygen supply and demand may result in a syndrome of acute cardiac ischemia. Potential mechanisms include acute changes in coronary anatomy, as in plaque rupture and thrombosis, and acute changes in physiology as in sepsis and hemorrhage.Acute cardiac ischemia progresses in a typical cascade through perfusion abnormality, metabolic disturbances, diastolic and systolic dysfunction, electrocardiographic changes, symptoms, and ultimately myocardial necrosis, with associated rise in serum biomarkers of myocardial infarction. Therapy to interrupt this cascade is time sensitive in order to prevent irreversible loss of myocytes.Key elements of initial evaluation of suspected acute cardiac ischemia include a chest pain history, focused examination to exclude alternate diagnoses and assess hemodynamic stability, and a 12-lead electrocardiogram to identify ST-segment elevations. Serum biomarkers of myocardial infarction including troponin creatine kinase and its MB fraction should be measured for diagnostic and prognostic purposes, but should not delay urgent management.Directed therapy for acute cardiac ischemia should target the suspected mechanism of ischemia. When plaque rupture, thrombosis, and acute obstruction to coronary blood flow are suspected, appropriate treatment includes dual antiplatelet therapy with aspirin and an adenosine diphosphate receptor antagonist, anticoagulation, statin therapy, and consideration of reperfusion therapy. When stable coronary anatomy and an acute change in physiology are suspected, treatment should prioritize correction of the offending physiologic derangements.Acute cardiac ischemia with ST-segment elevations is a medical emergency requiring immediate cardiology consultation and consideration of reperfusion therapy, including potential primary percutaneous coronary intervention or fibrinolytic therapy.