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Initial evaluation and management of suspected acute coronary syndrome (myocardial infarction, unstable angina) in the emergency department

Guy S Reeder, MD
Eric Awtry, MD
Simon A Mahler, MD, MS
Section Editors
James Hoekstra, MD
Christopher P Cannon, MD
Deputy Editor
Jonathan Grayzel, MD, FAAEM


The clinical presentation of myocardial ischemia is most often acute chest discomfort. The goal of emergency department evaluation is to determine the cause of the chest discomfort and promptly initiate appropriate therapy. It is essential that initial assessment and management be rapid but methodical and evidence-based.

Diagnostic evaluation emphasizes distinguishing among the following potential causes of chest pain:

Acute coronary syndrome (myocardial infarction or unstable angina)

Nonischemic chest pain, including potentially life-threatening conditions such as aortic dissection, pulmonary embolism, and esophageal rupture (table 1 and table 2A-B)

The diagnosis of acute coronary ischemia depends upon the characteristics of the chest pain, specific associated symptoms, abnormalities on electrocardiogram (ECG), and levels of serum markers of cardiac injury. A patient with a possible acute coronary syndrome (ACS) should be treated rapidly. Thus, initial management steps must be undertaken before or during the time the diagnosis is being established.

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Literature review current through: Nov 2017. | This topic last updated: Oct 03, 2016.
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  1. Pope JH, Ruthazer R, Beshansky JR, et al. Clinical Features of Emergency Department Patients Presenting with Symptoms Suggestive of Acute Cardiac Ischemia: A Multicenter Study. J Thromb Thrombolysis 1998; 6:63.
  2. Diercks DB, Peacock WF, Hiestand BC, et al. Frequency and consequences of recording an electrocardiogram >10 minutes after arrival in an emergency room in non-ST-segment elevation acute coronary syndromes (from the CRUSADE Initiative). Am J Cardiol 2006; 97:437.
  3. Kudenchuk PJ, Maynard C, Cobb LA, et al. Utility of the prehospital electrocardiogram in diagnosing acute coronary syndromes: the Myocardial Infarction Triage and Intervention (MITI) Project. J Am Coll Cardiol 1998; 32:17.
  4. Henrikson CA, Howell EE, Bush DE, et al. Chest pain relief by nitroglycerin does not predict active coronary artery disease. Ann Intern Med 2003; 139:979.
  5. Glickman SW, Shofer FS, Wu MC, et al. Development and validation of a prioritization rule for obtaining an immediate 12-lead electrocardiogram in the emergency department to identify ST-elevation myocardial infarction. Am Heart J 2012; 163:372.
  6. Goldberger AL. Myocardial Infraction: Electrocardiographic Differential Diagnosis, 4th, Mosby Yeark Book, St. Louis 1991.
  7. Goldberger AL. Clinical Electrocardiography: A Simplified Approach, 6th, Mosby, St. Louis 1999.
  8. Fesmire FM, Percy RF, Bardoner JB, et al. Usefulness of automated serial 12-lead ECG monitoring during the initial emergency department evaluation of patients with chest pain. Ann Emerg Med 1998; 31:3.
  9. Parodi O, Uthurralt N, Severi S, et al. Transient reduction of regional myocardial perfusion during angina at rest with ST-segment depression or normalization of negative T waves. Circulation 1981; 63:1238.
  10. Turnipseed SD, Trythall WS, Diercks DB, et al. Frequency of acute coronary syndrome in patients with normal electrocardiogram performed during presence or absence of chest pain. Acad Emerg Med 2009; 16:495.
  11. Chase M, Brown AM, Robey JL, et al. Prognostic value of symptoms during a normal or nonspecific electrocardiogram in emergency department patients with potential acute coronary syndrome. Acad Emerg Med 2006; 13:1034.
  12. Shlipak MG, Go AS, Frederick PD, et al. Treatment and outcomes of left bundle-branch block patients with myocardial infarction who present without chest pain. National Registry of Myocardial Infarction 2 Investigators. J Am Coll Cardiol 2000; 36:706.
  13. Go AS, Barron HV, Rundle AC, et al. Bundle-branch block and in-hospital mortality in acute myocardial infarction. National Registry of Myocardial Infarction 2 Investigators. Ann Intern Med 1998; 129:690.
  14. Rathore SS, Gersh BJ, Weinfurt KP, et al. The role of reperfusion therapy in paced patients with acute myocardial infarction. Am Heart J 2001; 142:516.
  15. Panju AA, Hemmelgarn BR, Guyatt GH, Simel DL. The rational clinical examination. Is this patient having a myocardial infarction? JAMA 1998; 280:1256.
  16. Swap CJ, Nagurney JT. Value and limitations of chest pain history in the evaluation of patients with suspected acute coronary syndromes. JAMA 2005; 294:2623.
  17. Goodacre S, Locker T, Morris F, Campbell S. How useful are clinical features in the diagnosis of acute, undifferentiated chest pain? Acad Emerg Med 2002; 9:203.
  18. Castrina FP. Unexplained noncardiac chest pain. Ann Intern Med 1997; 126:663; author reply 663.
  19. Ros E, Armengol X, Grande L, et al. Chest pain at rest in patients with coronary artery disease. Myocardial ischemia, esophageal dysfunction, or panic disorder? Dig Dis Sci 1997; 42:1344.
  20. Grailey K, Glasziou PP. Diagnostic accuracy of nitroglycerine as a 'test of treatment' for cardiac chest pain: a systematic review. Emerg Med J 2012; 29:173.
  21. Edwards M, Chang AM, Matsuura AC, et al. Relationship between pain severity and outcomes in patients presenting with potential acute coronary syndromes. Ann Emerg Med 2011; 58:501.
  22. Fanaroff AC, Rymer JA, Goldstein SA, et al. Does This Patient With Chest Pain Have Acute Coronary Syndrome?: The Rational Clinical Examination Systematic Review. JAMA 2015; 314:1955.
  23. Miller CD, Lindsell CJ, Khandelwal S, et al. Is the initial diagnostic impression of "noncardiac chest pain" adequate to exclude cardiac disease? Ann Emerg Med 2004; 44:565.
  24. Lee TH, Cook EF, Weisberg M, et al. Acute chest pain in the emergency room. Identification and examination of low-risk patients. Arch Intern Med 1985; 145:65.
  25. Canto JG, Shlipak MG, Rogers WJ, et al. Prevalence, clinical characteristics, and mortality among patients with myocardial infarction presenting without chest pain. JAMA 2000; 283:3223.
  26. Pope JH, Aufderheide TP, Ruthazer R, et al. Missed diagnoses of acute cardiac ischemia in the emergency department. N Engl J Med 2000; 342:1163.
  27. Brieger D, Eagle KA, Goodman SG, et al. Acute coronary syndromes without chest pain, an underdiagnosed and undertreated high-risk group: insights from the Global Registry of Acute Coronary Events. Chest 2004; 126:461.
  28. Boersma E, Pieper KS, Steyerberg EW, et al. Predictors of outcome in patients with acute coronary syndromes without persistent ST-segment elevation. Results from an international trial of 9461 patients. The PURSUIT Investigators. Circulation 2000; 101:2557.
  29. Khot UN, Johnson ML, Ramsey C, et al. Emergency department physician activation of the catheterization laboratory and immediate transfer to an immediately available catheterization laboratory reduce door-to-balloon time in ST-elevation myocardial infarction. Circulation 2007; 116:67.
  30. Han JH, Lindsell CJ, Storrow AB, et al. The role of cardiac risk factor burden in diagnosing acute coronary syndromes in the emergency department setting. Ann Emerg Med 2007; 49:145.
  31. Lee TH, Rouan GW, Weisberg MC, et al. Clinical characteristics and natural history of patients with acute myocardial infarction sent home from the emergency room. Am J Cardiol 1987; 60:219.
  32. McCarthy BD, Beshansky JR, D'Agostino RB, Selker HP. Missed diagnoses of acute myocardial infarction in the emergency department: results from a multicenter study. Ann Emerg Med 1993; 22:579.