Viral myocarditis is an inflammatory lesion of the myocardium caused by viral attack on the heart, sometimes involving the pericardium or endocardium, and is characterised by degeneration and necrosis of myocardial cells.
The symptoms may vary from asymptomatic in mild cases to heart failure, severe arrhythmias, cardiogenic shock and sudden death in severe cases, depending on age and the acute or chronic course of the infection. The most common symptoms are chest tightness, palpitations, dyspnoea, nausea and vomiting.