1. Myocarditis Viral (influenza, ECHO, HIV, CMV) Trypanosomiasis (S. American, Chaga’s disease – T cruzi) Non-infective (e.g. eosinophilia associated with parasites elsewhere, rheumatic fever, SLE)

2. Myocarditis is inflammation of the myocardium. It is generally due to infection(viral or bacterial). It may present with chest pain, rapid signs of heart failure, or sudden death.

3. Signs and symptoms The signs and symptoms associated with myocarditis are varied, and relate either to the actual inflammation of the myocardium, or the weakness of the heart muscle that is secondary to the inflammation. Signs and symptoms of myocarditis include: Chest pain (often described as "stabbing" in character). CHF(leading to edema,breathlessness and hepatic congestion). Palpitations (due to arrhythmias). Sudden death (in young adults, myocarditis causes up to 20% of all cases of sudden death). Fever (especially when infectious, e.g. in RF) Since myocarditis is often due to a viral illness, many patients give a history of symptoms consistent with a recent viral infection, including fever, diarrhea, joint pains, and easy fatigueability. Myocarditis is often associated with pericarditis, and many patients present with signs and symptoms that suggest concurrent myocarditis and pericarditis.

4. Diagnosis Myocardial inflammation can be suspected on the basis of ECG results,elevated CRP and/or ESR and increased IgM(serology) against viruses known to affect the myocardium. Markers of myocardial damage (troponin or CK cardiac isoenzymes) are elevated.

5. The gold standard is still biopsy of the myocardium, generally done in the setting of angiography. A small tissue sample of the endocardium and myocardium is taken, and investigated by a pathologist by light microscopy and—if necessary—immunochemistry and special staining methods. Histopathological features are: myocardial interstitium with abundant edema and inflammatory infiltrate, rich in lymphocytes and macrophages. Focal destruction of myocytes explains the myocardial pump failure.

6. Viral myocarditis:

7. Heart-microabscesses on the epicardial surface & in the myocardium

8. Causes A large number of different causes have been identified as leading to myocarditis: – Infectious: – Viral (e.g. enterovirus, Coxsackie virus, rubella,polio virus, cytomegalovirus, possibly hepatitis C ). – Bacterial (e.g. brucella, Corynebacterium diphtheriae, gonococcus,Haemophilus influenzae, and Vibrio Cholerae). – Spirochaetal (Borrelia and leptospira) – Protozoal (Toxoplasma and Trypanosoma Cruzi) – Fungal (e.g.aspergillus) – Parasitic:ascaris, Echinococcus Granulosus, shistosoma,Taenia solium, Trichinella spiralis, visceral larva migrans and Wuchereria bancrofti.

9. – Immunological: – Allergic (e.g.acetazolamide,amitryptiline) – Rejection after a heart transplant. – Autoantigens (e.g. Systemic vasculitis such asChurgstrauss syndrome,Wegener’s granulomatosis). – Toxic: – Drugs(e.g. anthracyclines and some other forms ofchemotherapy,ethanol, andantipsychotics, e.g.clozapine) – Toxins (e.g.arsenic,CO,snake venom) – Heavy metals (e.g.copper,iron) Physical agents (electric shock,hyperpyrexia andradiation). Bacterial myocarditis is rare in patients without immunodeficiency.

10. Myocarditis consequences: General effects of infection Arrhythmia Cardiac failure (acute or chronic)