Myocarditis

Question 1

Define Myocarditis

Answer 1

Inflammation of myocardium, associated with pericardial inflammation, in the absence of predominant ischaemia

Question 2

Aetiology of Myocarditis

Answer 2

Idiopathic (50%)
Viral: coxsacki B, enterovirus, adenovirus,
Bacterial: mycobacterium, strep
Spirochaetes
Protozoa
Drugs: penicillin, chloramphenicol
Toxins: cocaine, lithium

Question 3

Risk factors for Myocarditis

Answer 3

Infection
HIV
Smallpox vaccination
Autoimmune diseases

Question 4

Symptoms of Myocarditis

Answer 4

Chest pain
Dyspnoea, orthopnoea
Fatigue
Palpitations
Syncope 
Viral cause: flu-like prodrome

Question 5

Signs of Myocarditis on examination

Answer 5

Elevated neck veins
Sinus tachycardia
Hypotension
Rales
S3 gallop 
Pericardial friction rub

Question 6

Investigations for Myocarditis

Answer 6

ECG: non-specific ST changes | T wave inversion | arrhythmias

CRP + ESR: raised
Serum CK + CK-MB: raised
Troponin: raised
BNP: Raised

echo: global and regional left ventricular motion abnormalities and dilatation | diastolic dysfunction
CXR: bilateral pulmonary infiltrates (myocarditis-induced CHF)
Cardiac MRI: global early enhancement

Endomyocardial biopsy: histopathological findings of myocardial cellular infiltrates