Myocarditis

Background

• 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

Myopericarditis:

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

Related Topics

• Pericarditis

Further Reading

• ECG BASICS – Waves, Intervals, Segments and Clinical Interpretation
• ECG CLINICAL CASES – Your favourite ECG’s placed in clinical context with a challenging Q&A approach
• ECG and Cardiology Eponymous Syndromes – Cheats guide to eponymous emancipation
• ECG Reference Sites on the WEB – the best of the rest

Author Credits

• Words – John Larkin
• Pictures – Ed Burns
• Web Editing – Ed Burns

References

• 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.