• Myocardial inflammation in the absence of ischaemia.
  • Often associated with pericarditis , termed myopericarditis.
  • Usually a benign disease without serious long-term complications.
  • In the acute setting can cause arrhythmias, cardiac failure, cardiogenic shock and death.
  • May result in delayed dilated cardiomyopathy.

Causes of Myocarditis

  • Viral – including coxsackie B virus, HIV, influenza A, HSV, adenovirus.
  • Bacteria – including mycoplasma, rickettsia, leptospira.
  • Immune mediated – including sarcoidosis, scleroderma, SLE, Kawasaki’s disease.
  • Drugs / toxins – including clozapine, amphetamines.

ECG in Myocarditis

ECG changes can be variable and include:

  • Sinus tachycardia.
  • QRS / QT prolongation.
  • Diffuse T wave inversion.
  • Ventricular arrhythmias.
  • AV conduction defects.
  • With inflammation of the adjacent pericardium, ECG features of pericarditis can also been seen (= myopericarditis).

NB. The most common abnormality seen in myocarditis is sinus tachycardia with non-specific ST segment and T wave changes. 

ECG Examples

Example 1

  • Sinus tachycardia with non-specific ST segment changes


Example 2


  • Widespread concave ST elevation (pericarditic changes) in a child with viral myocarditis.


Related Topics

Further Reading

Author Credits


  • Surawicz B, Knilans TK. Chou’s Electrocardiography in Clinical Practice. 6th Edition. Saunders Elsevier 2008.
  • Chan TC, Brady WJ, Harrigan RA, Ornato JP, Rosen P. ECG in Emergency Medicine and Acute Care. Elsevier Mosby 2005.
  • Brady WJ, Truwit JD. Critical Decisions in Emergency & Acute Care Electrocardiography. Wiley Blackwell 2009.
  • Cameron P, Jelinek G, Kelly AM, Murray L, Brown A. Textbook of Adult Emergency Medicine. 3rd Edition. Churchill Livingston Elsevier 2009.
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