Cardiovascular System >
Myocarditis
“Acute or chronic inflammation of the myocardium”
Aetiology
- Infection
- Most commonly due to viral infection if acute (Coxsackie virus most common in Europe and the USA but most viruses are potential causes).
- May also be bacterial (diphtheria most common) or fungal/ parasitic
- Toxic
- Medication
- Exposure to heavy metals
- Shock
- Radiation
- Immune-Related
- Allergy
- Heart transplant rejection
- Autoimmune disorders
Pathophysiology
- The infection causes inflammation and injury to the myocytes.
- This leads to decreased myocardial contractility and cardiomyopathy.
- Arrhythmias occur when the injury heals by scarring
Clinical Presentation
- MAY PRESENT SIMILAR TO MYOCARDIAL INFARCTION
- Ranges from asymptomatic (incidental finding on ECG) to heart failure/ arrhythmia/ sudden cardiac death
- Fatigue
- Chest pain
- Fever
- Dyspnoea
- Palpitations
- Tachycardia
- Signs of heart failure
- Soft S1/ S4 gallop on auscultation
Investigations
- On Examination:
- Soft S1/ S4 gallop on auscultation
- Bloods:
- FBC, U+E, CK, CRP, LFT, Troponin
- Imaging:
- Chest X-Ray
- Special:
- ECG – serial changes of ST-elevation/depression, T wave inversion, atrial arrhythmias or transient AV block.
- Myocardial biopsy
Management
- Supportive treatment for symptom relief and treatment of the underlying cause
- Treatment of heart failure if present
- If severe may require a transplant
Complications
- Dilated cardiomyopathy due to myocardial destruction
- Congestive heart failure
- Pulmonary oedema
- Cardiogenic shock
- Arrhythmias
- Recurrent myositis