RT Book, Section A1 Hollenberg, Steven M. A2 Hall, Jesse B. A2 Schmidt, Gregory A. A2 Kress, John P. SR Print(0) ID 1107717288 T1 Myocardial Ischemia T2 Principles of Critical Care, 4e YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 9780071738811 LK accessmedicine.mhmedical.com/content.aspx?aid=1107717288 RD 2024/03/28 AB Myocardial ischemia results from an imbalance between myocardial oxygen demand and supply. The major determinants of myocardial oxygen requirements are heart rate, contractility, and wall stress (afterload).Patients with myocardial ischemia are divided by presentation into those with or without ST elevation, in accordance with treatment strategies. Patients with ST elevation benefit from immediate reperfusion with percutaneous coronary intervention or fibrinolytic agents.Myocardial infarction is diagnosed by a compatible clinical history, evolution of characteristic ECG changes, and an increase and decrease in cardiac enzymes.All patients with suspected myocardial ischemia should be given aspirin upon presentation.Prognosis after myocardial infarction is most closely related to the degree of left ventricular impairment.Risk stratification is the key to initial management of patients with non-ST elevation acute coronary syndromes.In patients with high-risk non-ST elevation acute coronary syndromes, an early invasive approach is preferred.Aspirin, clopidogrel, β-blockers, angiotensin converting enzyme inhibitors, and statins have been shown to decrease mortality after myocardial infarction.Echocardiography is extremely useful for the diagnosis of complications after myocardial infarction. Invasive hemodynamic monitoring may be necessary in some cases as well.Patients with cardiogenic shock should be stabilized with an intra-aortic balloon pump and revascularized promptly with percutaneous coronary intervention or bypass surgery.