Smarter Decisions,
Better Care

UpToDate synthesizes the most recent medical information into evidence-based practical recommendations clinicians trust to make the right point of care decisions.

  • Rigorous editorial process: Evidence-based treatment recommendations
  • World-Renowned physician authors: over 5,100 physician authors around the globe
  • Innovative technology: integrates into the workflow; access from EMRs

For more information, click below.


Subscribers log in here


Electrocardiogram in the diagnosis of myocardial ischemia and infarction

Topic Outline

GRAPHICS

INTRODUCTION

The electrocardiogram (ECG) is an important and central tool used to establish the diagnosis of myocardial ischemia or infarction. Abnormalities in the ST segment and T waves represent myocardial ischemia (and sometimes infarction) and may be followed by the formation of Q waves. However, the electrocardiogram may be normal or nonspecific in a patient with either ischemia or infarction. On the other hand, findings thought typical of acute myocardial infarction may occur in other conditions, such as myocarditis. (See "Clinical manifestations and diagnosis of myocarditis in adults".)

The use of the ECG for the diagnosis of myocardial ischemia and myocardial infarction (MI) will be reviewed here. This topic includes important updates on the ECG criteria for myocardial infarction (MI), including those made in the 2012 Joint European Society of Cardiology/American College of Cardiology Foundation/American Heart Association/World Health Federation (ESC/ACCF/AHA/WHF) Task Force in the Third Universal Definition of Myocardial Infarction [1]. (See "Criteria for the diagnosis of acute myocardial infarction", section on 'Definitions'.)

Also included in this report are specific ST segment (including elevation and depression) and T wave changes that may represent myocardial ischemia (table 1), as well as changes in the QRS complex associated with prior myocardial infarction (table 2). (See 'Localization of ischemia or infarction' below.)

The importance of the ECG in diagnosing ischemia and infarction was reinforced by the Myocardial Infarction Triage and Intervention (MITI) study [2]. The MITI project reviewed data on 3027 patients: ECG abnormalities were an early sign of myocardial ischemia and could be identified on a prehospital ECG within 90 minutes of symptom onset [2]. Persistent and transient ST segment and T or Q wave abnormalities on serial ECGs discriminated patients with from those without acute ischemia or infarction better than changes on a single ECG; dynamic changes in ST segment elevation between serial ECGs improved the overall sensitivity from 34 to 46 percent. When serial evolution of all ECG abnormalities (ST segment, T or Q waves, or left bundle branch block) were considered, the diagnostic sensitivity of the ECG increased from 80 to 87 percent with a fall in specificity from 60 to 50 percent.

It is also important to understand that ECG abnormalities are not the sole criteria for diagnosing MI. As will be described below, ECG changes may be absent or nonspecific, and when present may be due to ischemia without infarction or to non-ischemic disorders, such as acute pericarditis. Hence, infarction may be diagnosed by the appropriate combination of clinical and laboratory tests, in conjunction with (but not dependent upon) the presence of characteristic ECG changes.

                                 

Subscribers log in here

To continue reading this article you must have access through your hospital or your group practice, log in to your personal subscription, or purchase a personal subscription. For more information, click below.
Literature review current through: Apr 2013. | This topic last updated: Dec 7, 2012.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2013 UpToDate, Inc.
References
Top
  1. Thygesen K, Alpert JS, Jaffe AS, et al. Third universal definition of myocardial infarction. Circulation 2012; 126:2020.
  2. 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.
  3. Mirvis DM, Goldberger AL. Electrocardiography. In: Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 9th edition, Bonow RO, Mann DL, Zipes DP, Libby P (Eds), W.B. Saunders Company, Philadelphia 2011.
  4. Wagner GS, Macfarlane P, Wellens H, et al. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part VI: acute ischemia/infarction: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society. Endorsed by the International Society for Computerized Electrocardiology. J Am Coll Cardiol 2009; 53:1003.
  5. Zeymer U, Schröder R, Tebbe U, et al. Non-invasive detection of early infarct vessel patency by resolution of ST-segment elevation in patients with thrombolysis for acute myocardial infarction; results of the angiographic substudy of the Hirudin for Improvement of Thrombolysis (HIT)-4 trial. Eur Heart J 2001; 22:769.
  6. Schröder K, Wegscheider K, Zeymer U, et al. Extent of ST-segment deviation in a single electrocardiogram lead 90 min after thrombolysis as a predictor of medium-term mortality in acute myocardial infarction. Lancet 2001; 358:1479.
  7. Zeymer U, Schröder K, Wegscheider K, et al. ST resolution in a single electrocardiographic lead: a simple and accurate predictor of cardiac mortality in patients with fibrinolytic therapy for acute ST-elevation myocardial infarction. Am Heart J 2005; 149:91.
  8. Larson DM, Menssen KM, Sharkey SW, et al. "False-positive" cardiac catheterization laboratory activation among patients with suspected ST-segment elevation myocardial infarction. JAMA 2007; 298:2754.
  9. Goldberger, AL. Clinical Electrocardiography: A Simplified Approach, 7th ed, Mosby, Inc, St. Louis 2006.
  10. Thygesen K, Alpert JS, White HD, Joint ESC/ACCF/AHA/WHF Task Force for the Redefinition of Myocardial Infarction. Universal definition of myocardial infarction. Eur Heart J 2007; 28:2525.
  11. Liebson PR, Klein LW. The non-Q wave myocardial infarction revisited: 10 years later. Prog Cardiovasc Dis 1997; 39:399.
  12. Early effects of tissue-type plasminogen activator added to conventional therapy on the culprit coronary lesion in patients presenting with ischemic cardiac pain at rest. Results of the Thrombolysis in Myocardial Ischemia (TIMI IIIA) Trial. Circulation 1993; 87:38.
  13. Kerensky RA, Wade M, Deedwania P, et al. Revisiting the culprit lesion in non-Q-wave myocardial infarction. Results from the VANQWISH trial angiographic core laboratory. J Am Coll Cardiol 2002; 39:1456.
  14. Wong GC, Morrow DA, Murphy S, et al. Elevations in troponin T and I are associated with abnormal tissue level perfusion: a TACTICS-TIMI 18 substudy. Treat Angina with Aggrastat and Determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis in Myocardial Infarction. Circulation 2002; 106:202.
  15. Moon JC, De Arenaza DP, Elkington AG, et al. The pathologic basis of Q-wave and non-Q-wave myocardial infarction: a cardiovascular magnetic resonance study. J Am Coll Cardiol 2004; 44:554.
  16. Bayés de Luna A, Cino JM, Pujadas S, et al. Concordance of electrocardiographic patterns and healed myocardial infarction location detected by cardiovascular magnetic resonance. Am J Cardiol 2006; 97:443.
  17. Bogaty P, Boyer L, Rousseau L, Arsenault M. Is anteroseptal myocardial infarction an appropriate term? Am J Med 2002; 113:37.
  18. Shalev Y, Fogelman R, Oettinger M, Caspi A. Does the electrocardiographic pattern of "anteroseptal" myocardial infarction correlate with the anatomic location of myocardial injury? Am J Cardiol 1995; 75:763.
  19. Antman EM, Anbe DT, Armstrong PW, et al. ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction. www.acc.org/qualityandscience/clinical/statements.htm (Accessed on August 24, 2006).
  20. Casas RE, Marriott HJ, Glancy DL. Value of leads V7-V9 in diagnosing posterior wall acute myocardial infarction and other causes of tall R waves in V1-V2. Am J Cardiol 1997; 80:508.
  21. Kulkarni AU, Brown R, Ayoubi M, Banka VS. Clinical use of posterior electrocardiographic leads: a prospective electrocardiographic analysis during coronary occlusion. Am Heart J 1996; 131:736.
  22. Kontos MC, Desai PV, Jesse RL, Ornato JP. Usefulness of the admission electrocardiogram for identifying the infarct-related artery in inferior wall acute myocardial infarction. Am J Cardiol 1997; 79:182.
  23. Assali AR, Sclarovsky S, Herz I, et al. Comparison of patients with inferior wall acute myocardial infarction with versus without ST-segment elevation in leads V5 and V6. Am J Cardiol 1998; 81:81.
  24. Zimetbaum PJ, Josephson ME. Use of the electrocardiogram in acute myocardial infarction. N Engl J Med 2003; 348:933.
  25. Zimetbaum PJ, Krishnan S, Gold A, et al. Usefulness of ST-segment elevation in lead III exceeding that of lead II for identifying the location of the totally occluded coronary artery in inferior wall myocardial infarction. Am J Cardiol 1998; 81:918.
  26. Verouden NJ, Barwari K, Koch KT, et al. Distinguishing the right coronary artery from the left circumflex coronary artery as the infarct-related artery in patients undergoing primary percutaneous coronary intervention for acute inferior myocardial infarction. Europace 2009; 11:1517.
  27. Kinch JW, Ryan TJ. Right ventricular infarction. N Engl J Med 1994; 330:1211.
  28. Zehender M, Kasper W, Kauder E, et al. Right ventricular infarction as an independent predictor of prognosis after acute inferior myocardial infarction. N Engl J Med 1993; 328:981.
  29. Herz I, Assali AR, Adler Y, et al. New electrocardiographic criteria for predicting either the right or left circumflex artery as the culprit coronary artery in inferior wall acute myocardial infarction. Am J Cardiol 1997; 80:1343.
  30. Engelen DJ, Gorgels AP, Cheriex EC, et al. Value of the electrocardiogram in localizing the occlusion site in the left anterior descending coronary artery in acute anterior myocardial infarction. J Am Coll Cardiol 1999; 34:389.
  31. Arbane M, Goy JJ. Prediction of the site of total occlusion in the left anterior descending coronary artery using admission electrocardiogram in anterior wall acute myocardial infarction. Am J Cardiol 2000; 85:487.
  32. Haines DE, Raabe DS, Gundel WD, Wackers FJ. Anatomic and prognostic significance of new T-wave inversion in unstable angina. Am J Cardiol 1983; 52:14.
  33. de Zwaan C, Bär FW, Janssen JH, et al. Angiographic and clinical characteristics of patients with unstable angina showing an ECG pattern indicating critical narrowing of the proximal LAD coronary artery. Am Heart J 1989; 117:657.
  34. Rhinehardt J, Brady WJ, Perron AD, Mattu A. Electrocardiographic manifestations of Wellens' syndrome. Am J Emerg Med 2002; 20:638.
  35. Shvilkin A, Ho KK, Rosen MR, Josephson ME. T-vector direction differentiates postpacing from ischemic T-wave inversion in precordial leads. Circulation 2005; 111:969.
  36. Sasaki K, Yotsukura M, Sakata K, et al. Relation of ST-segment changes in inferior leads during anterior wall acute myocardial infarction to length and occlusion site of the left anterior descending coronary artery. Am J Cardiol 2001; 87:1340.
  37. Yamaji H, Iwasaki K, Kusachi S, et al. Prediction of acute left main coronary artery obstruction by 12-lead electrocardiography. ST segment elevation in lead aVR with less ST segment elevation in lead V(1). J Am Coll Cardiol 2001; 38:1348.
  38. Maeda S, Imai T, Kuboki K, et al. Pathologic implications of restored positive T waves and persistent negative T waves after Q wave myocardial infarction. J Am Coll Cardiol 1996; 28:1514.
  39. Bosimini E, Giannuzzi P, Temporelli PL, et al. Electrocardiographic evolutionary changes and left ventricular remodeling after acute myocardial infarction: results of the GISSI-3 Echo substudy. J Am Coll Cardiol 2000; 35:127.
  40. Nagase K, Tamura A, Mikuriya Y, Nasu M. Significance of Q-wave regression after anterior wall acute myocardial infarction. Eur Heart J 1998; 19:742.
  41. Akashi YJ, Nef HM, Möllmann H, Ueyama T. Stress cardiomyopathy. Annu Rev Med 2010; 61:271.
  42. http://jama.ama-assn.org/content/306/3/277.short (Accessed on December 19, 2011).
  43. 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.
  44. Antman, EM, Anbe, DT, Armstrong, PW, et al. ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction. www.acc.org/qualityandscience/clinical/statements.htm (Accessed on June 07, 2009).
  45. Pirwitz MJ, Lange RA, Landau C, et al. Utility of the 12-lead electrocardiogram in identifying underlying coronary artery disease in patients with depressed left ventricular systolic function. Am J Cardiol 1996; 77:1289.
  46. Ananthasubramaniam K, Chow BJ, Ruddy TD, et al. Does electrocardiographic Q wave burden predict the extent of scarring or hibernating myocardium as quantified by positron emission tomography? Can J Cardiol 2005; 21:51.
  47. Al-Mohammad A, Norton MY, Mahy IR, et al. Can the surface electrocardiogram be used to predict myocardial viability? Heart 1999; 82:663.
  48. Davidoff R, Goldman AP, Diamond TH, et al. The natural history of the Q wave in inferoposterior myocardial infarction. S Afr Med J 1982; 61:611.
  49. Richter A, Herlitz J, Hjalmarson A. QRS complex recovery during one year after acute myocardial infarction. Clin Cardiol 1987; 10:16.
  50. Voon WC, Chen YW, Hsu CC, et al. Q-wave regression after acute myocardial infarction assessed by Tl-201 myocardial perfusion SPECT. J Nucl Cardiol 2004; 11:165.
  51. Das MK, Khan B, Jacob S, et al. Significance of a fragmented QRS complex versus a Q wave in patients with coronary artery disease. Circulation 2006; 113:2495.
  52. Das MK, Zipes DP. Fragmented QRS: a predictor of mortality and sudden cardiac death. Heart Rhythm 2009; 6:S8.
  53. Sgarbossa EB, Pinski SL, Barbagelata A, et al. Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block. GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) Investigators. N Engl J Med 1996; 334:481.
  54. Wang K, Asinger RW, Marriott HJ. ST-segment elevation in conditions other than acute myocardial infarction. N Engl J Med 2003; 349:2128.
  55. Angelini A, Calzolari V, Calabrese F, et al. Myocarditis mimicking acute myocardial infarction: role of endomyocardial biopsy in the differential diagnosis. Heart 2000; 84:245.
  56. Sarda L, Colin P, Boccara F, et al. Myocarditis in patients with clinical presentation of myocardial infarction and normal coronary angiograms. J Am Coll Cardiol 2001; 37:786.
  57. Smith SW, Khalil A, Henry TD, et al. Electrocardiographic differentiation of early repolarization from subtle anterior ST-segment elevation myocardial infarction. Ann Emerg Med 2012; 60:45.
  58. Haïssaguerre M, Derval N, Sacher F, et al. Sudden cardiac arrest associated with early repolarization. N Engl J Med 2008; 358:2016.
  59. Tikkanen JT, Anttonen O, Junttila MJ, et al. Long-term outcome associated with early repolarization on electrocardiography. N Engl J Med 2009; 361:2529.
  60. Alpert JS, Thygesen K, Antman E, Bassand JP. Myocardial infarction redefined--a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction. J Am Coll Cardiol 2000; 36:959.
  61. Shvilkin A, Bojovic B, Vajdic B, et al. Vectorcardiographic determinants of cardiac memory during normal ventricular activation and continuous ventricular pacing. Heart Rhythm 2009; 6:943.