Paediatrics: Myocarditis

Myocarditis

Myocarditis may be due to:

• Infections: viral, e.g. coxsackie B, EBV.
• Kawasaki disease.
• Drugs: Adriamycin.
• Connective tissue disease: SLE; rheumatoid arthritis; rheumatic fever; sarcoidosis.

Clinical features

Variable and will depend on the age of the patient and on the time course of the underlying disease. Specific cardiovascular symptoms include progressive worsening of dyspnoea and congestive cardiac failure. Sudden onset of ventricular arrhythmia may occur.

Examination

The typical cardiovascular examination includes:

• weak pulses;
•  tachycardia;
• gallop heart rhythm;
• distant heart sounds.

Diagnosis

Echocardiography shows poor ventricular function. A definitive histological diagnosis is made after the percutaneous endomyocardial biopsy. CXR shows cardiomegaly; ECG shows reduced QRS complex size.

Treatment

This is directed at the underlying cause and at controlling symptoms of congestive heart failure. Arrhythmias should be treated. Cardiac transplantation is needed in patients with refractory heart failure.