eMedicine Specialties > Emergency Medicine > Cardiovascular

Myocarditis: Differential Diagnoses & Workup

Author: David S Howes, MD, Residency Program Director, Professor of Medicine, Section of Emergency Medicine, University of Chicago/Pritzker School of Medicine
Coauthor(s): Ethan A Booker, MD, Attending Physician, Department of Emergency Medicine, Washington Hospital Center
Contributor Information and Disclosures

Updated: Aug 5, 2008

Differential Diagnoses

Acute Coronary Syndrome
Pneumonia, Bacterial
Congestive Heart Failure and Pulmonary Edema
Pneumonia, Viral
Dissection, Aortic
Pulmonary Embolism
Esophageal Perforation, Rupture and Tears
Viral syndrome
Myocardial Infarction
Pediatrics, Kawasaki Disease

Workup

Laboratory Studies

  • Cardiac enzyme levels
    • These levels are only elevated in a minority of patients.
    • Normally, a characteristic pattern of slow elevation and fall over a period of days occurs; however, a more abrupt rise is observed in patients with acute myocardial infarction.
  • Cardiac troponin I may be more sensitive because it is present for longer periods after myocardial damage from any cause.2
  • Erythrocyte sedimentation rate (ESR) is elevated in 60% of patients with acute myocarditis.
  • Leukocytosis is present in 25% of cases.

Imaging Studies

  • Chest radiography
    • A chest radiograph often reveals a normal cardiac silhouette, but pericarditis or overt clinical CHF is associated with cardiomegaly.
    • Vascular redistribution
    • Interstitial and alveolar edema
    • Pleural effusion
  • Echocardiography
    • Impairment of left ventricular systolic and diastolic function
    • Segmental wall motion abnormalities
    • Impaired ejection fraction
    • A pericardial effusion may be present, although findings of tamponade are rare.
    • Ventricular thrombus has been identified in 15% of patients studied with echocardiography.
  • MRI is capable of showing abnormal signal intensity in the affected myocardium.
    • Cardiac MRI is an emerging field in general, and contrast-enhanced T1- weighted MRI has been shown to have sensitivities and specificities approaching 100% for diagnosis.3
    • MRI can demonstrate nodular and patchy areas of inflammation, often seen first in the lateral and inferior wall and can be used to guide later biopsy.
    • MRI is also one of the modalities used in the evaluation of young patients with apparently idiopathic dysrhythmias, and this imaging study can differentiate focal and diffuse inflammation from the rare electrically significant myocardial tumor.

Other Tests

  • Electrocardiography 
    • Sinus tachycardia is the most frequent finding.
    • ST-segment elevation without reciprocal depression, particularly when diffuse, is helpful in differentiating myocarditis from acute myocardial infarction.
    • Decreased QRS amplitude and transitory Q-wave development is very suggestive of myocarditis.
    • As many as 20% of patients will have a conduction delay, including Mobitz I, Mobitz II, or complete heart block.
    • Left or right bundle-branch block is observed in approximately 20% of abnormal ECG findings and may persist for months.
  • Viral isolation from other body sites may be supportive of the diagnosis.
  • Polymerase chain reaction (PCR) identification of a viral infection from myocardial tissue, pericardial fluid, or other body fluid sites can be helpful. Persistent viral genome, as detected by PCR, has been identified as one marker of increased incidence of dilated cardiomyopathy and mortality.
  • If a systemic disorder (eg, SLE) is suspected, antinuclear antibody (ANA) and other collagen vascular disorder laboratory investigations may be useful.

Procedures

  • Cardiac catheterization usually reveals normal coronary vessels and regional wall motion abnormalities with diminished ejection fraction. It has no benefit over noninvasive echocardiography.
  • Endomyocardial biopsy continues to be of use in diagnosing myocarditis  
    • The Dallas criteria, the classic histological criteria required for diagnosis of myocarditis, are no longer broadly accepted due to stated biopsy sample errors, problems with inter-rater reliability, and the identification of alternate patterns of inflammation besides the previously defined lymphocytic infiltrate with myocyte necrosis.4
    • The use of MRI to target biopsy, immunohistochemical staining, and the ability to identify viral genome by PCR has allowed endomyocardial biopsy to remain a powerful tool. In one study of nearly 900 patients, biopsy altered diagnosis in 21% of patients.

More on Myocarditis

Overview: Myocarditis
Differential Diagnoses & Workup: Myocarditis
Treatment & Medication: Myocarditis
Follow-up: Myocarditis
References
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References

  1. Diaz FJ, Loewe C, Jackson A. Death caused by myocarditis in Wayne County, Michigan: a 9-year retrospective study. Am J Forensic Med Pathol. Dec 2006;27(4):300-3. [Medline].

  2. Smith SC, Ladenson JH, Mason JW, Jaffe AS. Elevations of cardiac troponin I associated with myocarditis. Experimental and clinical correlates. Circulation. Jan 7 1997;95(1):163-8. [Medline].

  3. Laissy JP, Messin B, Varenne O, Iung B, Karila-Cohen D, Schouman-Claeys E, et al. MRI of acute myocarditis: a comprehensive approach based on various imaging sequences. Chest. Nov 2002;122(5):1638-48. [Medline].

  4. Baughman KL. Diagnosis of myocarditis: death of Dallas criteria. Circulation. Jan 31 2006;113(4):593-5. [Medline].

  5. Ardehali H, Kasper EK, Baughman KL. Diagnostic approach to the patient with cardiomyopathy: whom to biopsy. Am Heart J. Jan 2005;149(1):7-12. [Medline].

  6. Brady WJ, Ferguson JD, Ullman EA, Perron AD. Myocarditis: emergency department recognition and management. Emerg Med Clin North Am. Nov 2004;22(4):865-85. [Medline].

  7. Braunwald E, ed. Myocarditis. In: Heart Disease. 6th ed. 2001:1783-1793.

  8. Checchia P, Kulik P. Guidelines for the Treatment of Myocarditis in Infants and Children and Proceedings of the 2005 Pediatric Cardiac Intensive Care Symposium. November 2006.

  9. Chen H, Liu J, Yang M. Corticosteroids for viral myocarditis. Cochrane Database Syst Rev. 2006;(4):CD004471. [Medline].

  10. Ellis CR, Di Salvo T. Myocarditis: basic and clinical aspects. Cardiol Rev. Jul-Aug 2007;15(4):170-7. [Medline].

  11. Fenster BE, Chan FP, Valentine HA, Yang E, McConnell MV, Berry GJ, et al. Images in cardiovascular medicine. Cardiac magnetic resonance imaging for myocarditis: effective use in medical decision making. Circulation. Jun 6 2006;113(22):e842-3. [Medline].

  12. Hia CP, Yip WC, Tai BC, Quek SC. Immunosuppressive therapy in acute myocarditis: an 18 year systematic review. Arch Dis Child. Jun 2004;89(6):580-4. [Medline].

  13. Khabbaz Z, Grinda JM, Fabiani JN. Extracorporeal life support: an effective and noninvasive way to treat acute necrotizing eosinophilic myocarditis. J Thorac Cardiovasc Surg. Apr 2007;133(4):1122-3; author reply 1123-4. [Medline].

  14. Liu PP, Mason JW. Advances in the understanding of myocarditis. Circulation. Aug 28 2001;104(9):1076-82. [Medline].

  15. Magnani JW, Danik HJ, Dec GW Jr, DiSalvo TG. Survival in biopsy-proven myocarditis: a long-term retrospective analysis of the histopathologic, clinical, and hemodynamic predictors. Am Heart J. Feb 2006;151(2):463-70. [Medline].

  16. Magnani JW, Dec GW. Myocarditis: current trends in diagnosis and treatment. Circulation. Feb 14 2006;113(6):876-90. [Medline].

  17. Martin TN, Groenning BA, Dargie HJ. Clinical vignette. Diagnosing acute myocarditis using cardiac MRI. Eur Heart J. Feb 2006;27(4):468. [Medline].

  18. Martino TA, Petric M, Weingartl H, Bergelson JM, Opavsky MA, Richardson CD, et al. The coxsackie-adenovirus receptor (CAR) is used by reference strains and clinical isolates representing all six serotypes of coxsackievirus group B and by swine vesicular disease virus. Virology. May 25 2000;271(1):99-108. [Medline].

  19. Mason JW, O'Connell JB, Herskowitz A, Rose NR, McManus BM, Billingham ME, et al. A clinical trial of immunosuppressive therapy for myocarditis. The Myocarditis Treatment Trial Investigators. N Engl J Med. Aug 3 1995;333(5):269-75. [Medline].

  20. Packer M, O'Connor CM, Ghali JK, Pressler ML, Carson PE, Belkin RN, et al. Effect of amlodipine on morbidity and mortality in severe chronic heart failure. Prospective Randomized Amlodipine Survival Evaluation Study Group. N Engl J Med. Oct 10 1996;335(15):1107-14. [Medline].

  21. Pisani B, Taylor DO, Mason JW. Inflammatory myocardial diseases and cardiomyopathies. Am J Med. May 1997;102(5):459-69. [Medline].

  22. Si X, Wang Y, Wong J, Zhang J, McManus BM, Luo H. Dysregulation of the ubiquitin-proteasome system by curcumin suppresses coxsackievirus B3 replication. J Virol. Apr 2007;81(7):3142-50. [Medline].

  23. Stevens LW. Diseases of the myocardium. In: Bennett JC, Plum F, eds. Cecil Textbook of Medicine. 20th ed. Philadelphia, Pa: WB Saunders Co; 1996:328-331.

  24. Vallejo J, Mann DL. Antiinflammatory therapy in myocarditis. Curr Opin Cardiol. May 2003;18(3):189-93. [Medline].

  25. Wang JF, Meissner A, Malek S, Chen Y, Ke Q, Zhang J, et al. Propranolol ameliorates and epinephrine exacerbates progression of acute and chronic viral myocarditis. Am J Physiol Heart Circ Physiol. Oct 2005;289(4):H1577-83. [Medline].

  26. Wojnicz R, Nowalany-Kozielska E, Wojciechowska C, Glanowska G, Wilczewski P, Niklewski T, et al. Randomized, placebo-controlled study for immunosuppressive treatment of inflammatory dilated cardiomyopathy: two-year follow-up results. Circulation. Jul 3 2001;104(1):39-45. [Medline].

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Further Reading

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Keywords

myocarditis, heart inflammation, dilated cardiomyopathy, inflammatory changes in the heart muscle, myocyte necrosis, viral myocarditis, acute myocarditis, inflammatory myocarditis, Chagas disease, coxsackievirus B, influenza virus, echovirus, herpes simplex virus, varicella-zoster virus, Epstein-Barr virus, cytomegalovirus, hepatitis C, HIV, diphtheria, Bartonella species, Brucella species, Leptospira species, Salmonella species, endocarditis, Borrelia burgdorferi, toxic myocarditis, parasitic myocarditis

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Contributor Information and Disclosures

Author

David S Howes, MD, Residency Program Director, Professor of Medicine, Section of Emergency Medicine, University of Chicago/Pritzker School of Medicine
David S Howes, MD is a member of the following medical societies: American College of Emergency Physicians, American College of Physicians-American Society of Internal Medicine, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Coauthor(s)

Ethan A Booker, MD, Attending Physician, Department of Emergency Medicine, Washington Hospital Center
Ethan A Booker, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Medical Editor

Eric M Kardon, MD, FACEP, Attending Emergency Physician, Georgia Emergency Medicine Specialists and Emergency Physicians of Tidewater; Division of Emergency Medicine, Athens Regional Medical Center
Eric M Kardon, MD, FACEP is a member of the following medical societies: American College of Emergency Physicians
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Paul Blackburn, DO, FACOEP, FACEP, Program Director, Department of Emergency Medicine, Maricopa Medical Center; Assistant Professor, Department of Surgery, University of Arizona
Paul Blackburn, DO, FACOEP, FACEP is a member of the following medical societies: American College of Emergency Physicians, American College of Osteopathic Emergency Physicians, American Medical Association, and Arizona Medical Association
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

David FM Brown, MD, Assistant Professor, Department of Medicine, Division of Emergency Medicine, Harvard Medical School; Associate-Chief, Attending Physician, Department of Emergency Medicine, Massachusetts General Hospital
David FM Brown, MD is a member of the following medical societies: American College of Emergency Physicians and Society for Academic Emergency Medicine
Disclosure: Schering  Honoraria Speaking and teaching

 
 
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