- 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.
LITFL Further Reading
- ECG Library Basics – Waves, Intervals, Segments and Clinical Interpretation
- ECG A to Z by diagnosis – ECG interpretation in clinical context
- ECG Exigency and Cardiovascular Curveball – ECG Clinical Cases
- 100 ECG Quiz – Self-assessment tool for examination practice
- ECG Reference SITES and BOOKS – the best of the rest
- Brady WJ, Truwit JD. Critical Decisions in Emergency and Acute Care Electrocardiography
- Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric
- Wagner GS. Marriott’s Practical Electrocardiography 12e
- Chan TC. ECG in Emergency Medicine and Acute Care
- Rawshani A. Clinical ECG Interpretation
- Mattu A. ECG’s for the Emergency Physician
- Hampton JR. The ECG In Practice, 6e