Myocarditis Flashcards
What is myocarditis?
Inflammation of the myocardium most often caused by viral infections
Myocarditis can lead to serious complications if not addressed.
What are the main viral infections that can cause myocarditis?
- enteroviruses (especially coxsackie virus B)
- human herpes virus 6
- parovirus B19
- influenza A
- HIV
Viral infections are the most common cause of myocarditis.
Name two bacterial or parasitic infections that can lead to myocarditis.
- rheumatic fever (strep A)
- Chagas disease (trypanosoma cruzi)
These infections can lead to myocarditis through different mechanisms.
What are some other causes of myocarditis apart from infections?
- radiation to chest
- autoimmune disorders (SLE, sarcoid, giant cell myocarditis, Kawasaki)
Autoimmune disorders can trigger inflammation in the myocardium.
Which drug is known to be associated with myocarditis?
Clozapine
Clozapine is an antipsychotic medication that may have this rare side effect.
What are the key mechanisms involved in viral myocarditis pathophysiology?
- direct cellular injury from viral infection
- immune response arising from viral proteins intracellularly
These mechanisms can lead to inflammation and damage to heart tissue.
What are common clinical features of myocarditis?
- chest pain (35%)
- systemic upset (fatigue >50%, fevers 20%)
- shortness of breath
- reduced exercise tolerance
- palpitations
- collapse
- sudden death
Symptoms can vary widely and may overlap with other conditions.
What is the significance of chest pain in myocarditis?
May also suggest concurrent pericarditis
Chest pain can be a key symptom but may indicate other cardiac issues.
What are some examination findings in myocarditis?
- signs of heart failure (raised JVP, pulmonary oedema, peripheral oedema)
- pericardial friction rub (if concurrent pericarditis)
- pansystolic murmur (if mitral regurgitation)
Physical examination can reveal critical signs of cardiac dysfunction.
What are some important investigations for myocarditis?
- ECG (ST elevation/depression, T-wave inversion, AV block)
- respiratory viral screening
- raised CRP and ESR
- raised cardiac enzymes (CK and troponin)
These tests help confirm the diagnosis and assess the severity.
What is the primary management approach for myocarditis?
- supportive treatment (oxygen, monitoring for arrhythmias, fluid balance, treat underlying cause)
Management is generally supportive, focusing on stabilizing the patient.
What are some short-term complications of myocarditis?
- cardiogenic shock
- cardiac arrhythmias
- sudden death
These complications can arise rapidly and require immediate intervention.
Name a medium to long-term complication of myocarditis.
Dilated cardiomyopathy
This condition can develop as a sequela of myocarditis, leading to chronic heart failure.
True or False: Sudden death can occur from previously undiagnosed myocarditis.
True
Approximately 8.6% of sudden cardiac deaths are attributed to undiagnosed myocarditis.
