Myocarditis Flashcards
Define myocarditis
Acute inflammation & necrosis of cardiac muscle (myocardium)
Aetiology of myocarditis
general +8
Usually IDIOPATHIC
Viruses Bacteria Fungal Protozoal Helminths Non-infective Drugs Others
Aetiology of myocarditis - viruses
5
Coxsackie B EBV CMV Adenovirus Influenza
Aetiology of myocarditis - bacterial
3
Post streptococcal
Tuberculosis
Diphtheria
Aetiology of myocarditis - fungal
Candidiasis
Aetiology of myocarditis - protozoal
Trypanosomiasis (Chagas disease)
Aetiology of myocarditis - helminths
Trichinosis
Aetiology of myocarditis - non infective
2
Systemic: SLE, sarcoidosis, polymyositis
Hypersensitivity myocarditis: sulphonamides
Aetiology of myocarditis - drugs
Chemotherapy agents (e.g. doxorubicin, streptomycin)
Aetiology of myocarditis - others
3
Cocaine, heavy metals, radiation
Epidemiology of myocarditis
prevalence, causes x2
Incidence difficult to measure accurately
Coxsackie B virus is most common in Europe & USA
Chagas disease most common in South America
Presenting symptoms of myocarditis
1.4 +3
Prodromal flu like illness fever malaise fatigue lethargy Breathlessness (due to pericardial effusion/myocardial dysfunction) Palpitations Sharp chest pain (suggesting pericarditis also)
Signs of myocarditis on physical examination
2
Signs of pericarditis
Signs of complications (e.g. heart failure, arrhythmia)
Investigations for myocarditis
6 types
Bloods ECG CXR Pericardial fluid drainage Echocardiography Myocardial biopsy
Investigations for myocarditis - bloods
5
FBC - raised WCC if infective cause U&Es ESR/CRP - raised Cardiac enzymes - may be raised Tests to identify cause (e.g. viral/bacterial serology, ANA, TFT)
Investigations for myocarditis - ECG
2
Non-specific T wave & ST changes
PERICARDITIS = widespread saddle shaped ST elevation
Investigations for myocarditis - CXR
2
May be normal
May show cardiomegaly
Investigations for myocarditis - pericardial fluid drainage
2
Measure glucose, protein, cytology, culture & sensitivity
Helps identify causative organism
Investigations for myocarditis - echocardiography
3
Assesses systolic/diastolic function
Wall motion abnormalities
Pericardial effusions
Investigations for myocarditis - myocardial biopsy
Rarely required