myocarditis Flashcards
what is it
acute inflammation of the myocardium
causes
- idiopathic
- infective
- toxic
- autoimune
- alcohol
- hydrocarbons
what are the infective causes
- adenovirus
- HIV
- polio
- parasites
- bacterial (streptococcus, diphtheria)
- lyme disease
- fungal
what are the toxic causes
- drugs
- penicillin
- radiation
what are the autoimmune causes
- giant cell myocarditis
- autoimmune form
what is the most common cause in the west
Coxsackie or adenoviral infection
what is Chagas’ disease due to
trypansoma cruzi
what is the pathology of the acute phase
heart is flabby with focal haemorrhages
what is the pathology of chronic phase
heart is enlarged and hypertrophied
what is seen histologically
inflammatory infiltrate is present
what predominates with viral causes
lymphocytes
what predominates with bacterial causes
polymorphonuclear
what predominates with allergic and hypersensitivity causes
eosinophils
symptoms
- asymptomatic
- fatigue
- palpitations
- chest pain
- dyspnoea
- fulminant congestive cardiac failure
physical examination
- soft heart sounds
- prominent third sound
- tachycardia
- pericardial friction rub may be heard
what investigations are don e
- CXR
- ECG
- cardiac enzymes
- viral antibody titres
- endomyocardial biopsy
- viral RNA
what is seen on CXR
cardiac enlargement
what is seen on ECG
- ST and T wave abnormalities
- arrhythmias
- heart block
- lyme disease
- chugs disease
what are the cardiac enzymes
elevated
what can biopsy show
acute inflammation
what is the viral RNA
they PCR it
what is the mainstay of treatment
supportive with heart failure medications
what is further therapy
antibiotics and steroids
what is treatment for acute phase
- bed rest is common
- avoid athletic activities for 6 months
what is used to treat heart failure
- diuretics
- ACE inhibitors / ARB
- beta blocker
or - spironolactone
when should antibiotics be administered
immediately
what is contraindicated in acute phase
NSAIDs
what helps resolve left ventricular dysfunction
IV immunoglobulin
what is giant cell myocarditis characterised by
presence of multinucleate giant cells within the myocardium
what is the cause of giant cell myocarditis
associated with sarcoidosis, thymomas and autoimmune disease
what is the cause of chagas’ disease
trypanosoma cruzi
