myocarditis Flashcards
definition of myocarditis
Acute inflammation and necrosis of cardiac muscle (myocardium).
often associated with pericardial inflammation - myopericarditis
aetiology of myocarditis
infective
non-infective
drugs
cocaine
heavy metals
radiation
lithium
arsenic
infective causes of myocarditis
Viruses: e.g. Coxsackie B, echovirus, EBV, CMV, adenovirus, influenza, enterovirus, HHV6, hepatitis, mumps, rubeola, coxsackie, polio, HIV, HSV
Bacterial: e.g. post-streptococcal, tuberculosis, diphtheria, strep, clostridia, TB, meningococcus, mycoplasma, brucellosis, psittacosis
spirochaetes: Lyme disease, leprospirosis, syphilis
Fungal: e.g. candidiasis.
Protozoal: e.g. trypanosomiasis (Chagas disease), leisgmania, toxoplasmosis
Helminths: e.g. trichinosis.
non-infective myocarditis causes
systemic disorders - SLE, sarcoidosis, polymyositis
hypersensitivity myocarditis eg sulphonaemides
kawasaki
scleroderma
heart transplant rejection
drug causes of myocarditis
- chemotherapy agents - doxorubicin, streptomycin
- cyclophosphamide
- trastuzumab
- penicillin
- chloramphenicol
- sulfonamides
- methyldopa
- spironolactone
- phenytoin
- carbamazepine
epidemiology of myocarditis
incidence unknown - many not detected at time of acute illness
Coxsackie B virus is a common cause in Europe and the USA.
Chagas disease is a common cause in South America.
sx of myocarditis
prodromal flu like illness - fever, malaise, fatigue, lethargy
breathlessness - pericardial effusion/myocardial dysfunction
palpitations
sharp chest pain - suggesting associated pericarditis
ACS and HF like symptoms
signs of myocarditis
signs of concurrent pericarditis or complications: HF/arrhythmia
tachycardia
soft S1, S4 gallop
Ix for myocarditis
- bloods
- ecg
- cxr
- pericardial fluid drainage - measure glucose, protein, cytology, culture and sensitivity
- echo
- cardiac MR if clinically stable
- myocardial biopsy - rarely required - result doesnt influence managemen
bloods for myocarditis
FBC (raised WCC in infective causes), UE, raised ESR or CRP, cardiac enzymes may be raised
identify the cause (viral or bacterial serology, antistreptolysin O titre, ANA, serum ACE, TFT).
ecg for myocarditis
non-specific T and ST changes
saddle-shaped ST elevation in pericarditis
cxr for myocarditis
normal
cardiomegaly w or w/o pul oedema
echo for myocarditis
assesses systolic/diastolic function
wall motion abnormalities
pericardial effusion
mx of haemodynamically stable myocarditis
supportive and rx of cause
consider IVIG
if LV systolic disfunction - ACE or ARB or valsartan
mx of haemodynamically unstable myocarditis
arterial vasodilator and invasive haemodynamic monitoring
* nitroprusside
* arterial catheter
consider inotrope/vasopresser
stable mx
