Overview
Definition
Inflammation of the myocardium (heart muscle), leading to myocardial necrosis and dysfunction.
Epidemiology
Can affect any age, but a notable cause of sudden cardiac death in young adults.
Etiology & Risk Factors
- Viral infections (Coxsackievirus B, Parvovirus B19, Adenovirus, SARS-CoV-2)
- Trypanosoma cruzi (Chagas disease - endemic in South America)
- Autoimmune disorders
- Toxins / Drugs (Doxorubicin, Immune Checkpoint Inhibitors)
Clinical Symptoms
- Viral prodrome (fever, myalgias, fatigue) followed by cardiac symptoms
- Chest pain (often mimics MI or pericarditis)
- Signs of heart failure (dyspnea, orthopnea, edema)
- Palpitations/Syncope (due to arrhythmias)
Clinical Approach
Diagnosis
- Elevated Troponins (often out of proportion to ECG changes)
- ECG: Non-specific ST-T changes or sinus tachycardia
- Echocardiogram: Global ventricular dysfunction
- Cardiac MRI: Late gadolinium enhancement (highly sensitive)
- Endomyocardial Biopsy (Gold Standard, but rarely done)
Management
- Supportive care (Guideline-directed medical therapy for heart failure)
- Avoid physical activity/competitive sports for at least 3-6 months to prevent sudden death
- Immunosuppression (in specific autoimmune/giant cell etiologies)
Complications
- Dilated Cardiomyopathy
- Heart Failure
- Lethal Arrhythmias