- 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.
- Sinus tachycardia with non-specific ST segment changes
- Widespread concave ST elevation (pericarditic changes) in a child with viral myocarditis.
- 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.