It is the inflammation of the myocardium(middle layer) of heart.


1. Infection:
–– Viral—Coxsackie A and B, influenza A and B.
–– Bacterial—Streptococcus, Pneumococcus, Borrelia burgdorferi (Lyme disease).
–– Protozoal—Trypanosoma cruzi (Chaga’s disease).
–– Fungal—candida, actinomyces.
2. Rheumatic fever.
3. Diphtheric myocarditis.
4. Drugs and toxins—doxorubicin, lithium, cocaine, penicillin, sulphonamide.
5. Radiation.
6. Autoimmune—SLE, Rheumatoid arthritis.
7. Unknown cause.

Clinical Features


• May be asymptomatic.
• Plapitation, breathlessness, chest pain.
• Features of cardiac failure.
• Features of primary disease, if any.


• Pulse—low volume, tachycardia.
• Apex beat may be displaced downwards and outwards due to cardiomegaly.
• First and second heart sounds may be soft.
• S3/S4 may be present.
• Mitral regurgitation may be present.
• Features of heart failure.
• Arrhythmia may be present.


• Chest X-ray.
• ECG—nonspecific ST and T wave changes.
• Echocardiography—low ejection fraction and global hypokinesia.
• MRI.
• Endomyocardial biopsy may be needed for confirmation.

Treatment of Myocarditis

• Complete bed rest.
• Low salt diet.
• Diuretics therapy.
• ACE inhibitors may be helpful.
• Treatment of arrhythmia.
• Treatment of primary cause, if any.