Myocarditis

Question 1

Define myocarditis

Answer 1

DEFINITION: acute inflammation and necrosis of cardiac muscle (myocardium)

Question 2

Summarise the epidemiology of myocarditis

Answer 2

• Incidence is difficult to measure accurately
• Coxsackie B virus is most common in Europe and USA
• Chagas disease is most common in South America

Question 3

What are the symptoms of coxsackie B virus infection?

Answer 3

Flu like symptoms then this can lead to myocarditis and pericarditis

Question 4

Explain the aetiology/risk factors of myocarditis

Answer 4

• Usually IDIOPATHIC
• Viruses
○ Coxsackie B
○ EBV
○ CMV
○ Adenovirus
○ Influenza

• Bacteria
○ Post-streptococcal
○ Tuberculosis
○ Diphtheria

• Fungal
○ Candidiasis

• Protozoal
○ Trypanosomiasis (Chagas disease)

• Helminths
○ Trichinosis

• Non-infective
○ Systemic: SLE, sarcoidosis, polymyositis
○ Hypersensitivity myocarditis: sulphonamides

• Drugs
○ Chemotherapy agents (e.g. doxorubicin, streptomycin)

• Others
○ Cocaine, heavy metals, radiation

Question 5

Recognise the presenting symptoms of myocarditis

Answer 5

• Prodromal flu-like illness with:
○ Fever
○ Malaise
○ Fatigue
○ Lethargy - muscle weakness

• Breathlessness (due to pericardial effusion/myocardial dysfunction)
• Palpitations
• Sharp chest pain (suggesting there is also pericarditis)

Question 6

Recognise the signs of myocarditis on examination

Answer 6

• Signs of pericarditis; pericardial friction rub. nausea, dyspnoea
• Signs of complications (e.g. heart failure, arrhythmia)

Question 7

Identify appropriate investigations for myocarditis

Answer 7

• Bloods
○ FBC - raised WCC if infective cause
○ U&E
○ ESR/CRP - raised
○ Cardiac enzymes - may be raised
○ Tests to identify cause (e.g. viral/bacterial serology, ANA, TFT)
ANA - antinuclear antibody for SLE

• ECG
○ Non-specific T wave and ST changes
○ PERICARDITIS: widespread saddle-shaped ST elevation

• CXR
○ May be NORMAL
○ May show cardiomegaly

• Echocardiography
○ Assesses systolic/diastolic function
○ Wall motion abnormalities
○ Pericardial effusions

Optional:
1. Cardiac mri

• Pericardial Fluid Drainage
○ Measure glucose, protein, cytology, culture and sensitivity
○ Helps identify causative organism
• Myocardial Biopsy
○ Rarely required

Question 8

mx?

Answer 8

if LVEF:
treat jsut like HF -> BASE

no LVEF, autoimmune;
methylprednisolone