Myocarditis (CV) Flashcards
Define myocarditis.
Inflammation of the myocardium in the absence of the predominant acute or chronic ischaemia characteristic of coronary artery disease
(Non-ischaemic myocardial inflammation resulting from a heterogeneous group of infectious, immune and non-immune diseases)
What is myocarditis characterised by histopathologically?
Inflammatory cellular infiltrate with or without evidence of myocyte injury
What % of sudden deaths in young adults does myocarditis make up?
10%
What is the average age of patients who get myocarditis?
40
What are the causes of myocarditis? (6 + 4)
- idiopathic - most common
- viral - Coxsackie B, parvovirus, influenza A&B, adenovirus, EBV, CMV
- bacterial - mycobacterial, streptococcal
- fungal
- parasitic
- non-infectious:
- connective tissue diseases e.g. SLE, sarcoidosis
- toxic myocarditis - cocaine, toxins, medication, alcohol
- autoimmune
- drugs - chemo agents, penicillin, chloramphenicol
Who is myocarditis more common in?
Can affect all age groups (mainly around 40y), with an apparent slightly higher incidence in males than females, and equal incidence in black people and white people
What might myocarditis lead to?
Death
What does the prognosis of myocarditis relate to?
Variable prognosis, related to presentation and underlying aetiology:
- viral myocarditis - asymptomatic, spontaneously resolve
- mild-mod HF - tends to improve but may progress to chronic severe HF
- fulminant, acutely decompensated HF - usually recover back to baseline function (if death is prevented through management in acute phase)
What are the clinical features of myocarditis? (6)
- prodromal flu-like/viral syndrome - fever, malaise, myalgia, lethargy, URTI symptoms 2-3 weeks before initial presentation
- usually young (<50) with acute Hx (recent flu-like illness)
- dyspnoea/SOB (due to pericardial effusion, myocardial dysfunction)
- chest pain (indicates perimyocarditis)
- palpitations (cardiac arrhythmias)
- dyspnoea, orthopnoea, fatigue
What might you see on examination in myocarditis? (5)
- rales
- tachycardia
- elevated neck veins
- soft S1, S3 gallop, S4 gallop
- signs of complications - HF, arrhythmia
What can help differentiate pericarditis from myocarditis?
Acute pulmonary oedema in myocarditis
What are the risk factors for myocarditis? (5)
- infection (non-HIV)
- HIV infection
- autoimmune/immune-mediated diseases
- peripartum and postnatal periods
- drugs and toxins
What are the 1st-line investigations for myocarditis? (5)
- 12-lead ECG
- CXR
- cardiac enzymes - serum CK, serum CK-MB, serum troponin
- bloods
- endomyocardial biopsy
What might you see on ECG in myocarditis? (3 + pericarditis)
- non-specific ST-segment and T-wave abnormalities:
- ST elevation
- T wave inversion
- tachycardia
- arrhythmias (atrial)
- PERICARDITIS: widespread saddle-shaped ST elevation
What might you see on CXR in myocarditis? (3)
- cardiomegaly
- pleural effusions
- bilateral pulmonary infiltrates due to CHF - pulmonary oedema
What would you see on bloods in myocarditis? (3)
- increased cardiac enzymes (troponin, CK)
- increased ESR
- increased BNP
What are some differential diagnoses for myocarditis? (4)
- ACS - atherosclerosis
- dilated cardiomyopathy - Fx, overlap
- pericarditis
- stress-induced cardiomyopathy - acute emotional/physical stressor, rapid recovery within 4-8wk
How do we differentiate pericarditis from myocarditis? (5)
- present similarly and can co-exist
- also presents with viral symptoms
- isolated pericarditis would not cause signs and symptoms of LV dysfunction
- troponin less likely to be raised
- global concave (saddle) ST elevation on ECG rather than focal changes seen in myocarditis
Which people should myocarditis be a differential in?
Young people with new onset chest pain with a recent history of viral illness
What does management of myocarditis involve? (2)
- supportive treatment (e.g. of HF or arrhythmias):
- cardiac monitoring
- O2 administration
- analgesics
- treatment of underlying cause:
- Abx for bacterial myocarditis
- antimycotics for fungal myocarditis
What is the first-line treatment for haemodynamically stable myocarditis?
Supportive care + treatment of underlying cause
What is the first-line treatment for haemodynamically stable myocarditis with LV systolic dysfunction?
- ACEi/ARB + SGLT2 inhibitor
- treat underlying cause
- consider IV immunoglobulin
- consider beta-blocker
- consider vasodilator/inotrope
- consider diuretics
- consider aldosterone antagonist
- consider long-term anticoagulation therapy
What is the first-line treatment for haemodynamically unstable myocarditis? (4)
- 1st line: arterial vasodilator (nitroprusside) + invasive haemodynamic monitoring
- IV GTN (glyceryl trinitrate)
- IV inotrope/vasopressor
- IV immunoglobulin
What is the first-line treatment for refractory cardiogenic shock - myocarditis? (4)
- intra-aortic balloon pump
- LVAD
- ECMO
- CPR (paediatric)
What is the 1st&2nd-line treatment for end-stage heart failure/refractory life-threatening arrhythmias from myocarditis?
- 1st line: heart transplantation
- 2nd line: LVAD + anticoagulation
What are some complications of myocarditis? (5)
- congestive heart failure (treated with diuretics + beta-blockers)
- arrhythmias (possibly leading to sudden death)
- dilated cardiomyopathy (late complication)
- pericarditis –> cardiac tamponade
- multisystem organ failure + death