“I have a sore throat, diarrhoea and vomiting.”

Eighty-nine percent of patients report a viral prodrome of symptoms such as myalgia and malaise, upper respiratory tract symptoms and/or gastroenteritis; 60% of patients report a fever (Mason et al. 1995). Clearly such symptoms may cause the clinician not to consider an underlying cardiac pathology which is a major diagnostic pitfall in the management of myocarditis and could have serious consequences.

“My chest hurts. I find it hard to breath.”

Myocarditis may coexist with pericardial inflammation and is termed my-pericarditis. Symptoms of left sided pleuritic chest pain, characteristically relieved by sitting forward, may therefore be present.

“I had chest pains before I collapsed.”

Patients presenting with chest pain, ECG changes and elevated cardia enzymes consistent with myocardial ischaemia or infarction may be initially misdiagnosed with acute coronary syndrome or myocardial infarction. If myocardial function is affected by the disease process then symptoms of cardiac failure will be present (ie. breathlessness, orthopnoea and peripheral swelling).

A younger patient with few risk factors for coronary artery disease should prompt consideration of a diagnosis of myocarditis, in particular if the ECG changes extend beyond the territory of a single coronary artery or are global.

Learning Bite

Beware the younger patient with no coronary risk factors presenting with chest pain and ECG changes: this may be myocarditis not an acute coronary syndrome.

“My heart beat has been really fast and I fainted.”

In some cases (approximately 15%) myocarditis can present with palpitations as a manifestation of an atrial or ventricular arrhythmia. Myocarditis may also present with sudden death. This is thought to be due to a malignant arrhythmia.

“He has been cranky and has difficulty breathing.”

In young children poor feeding, irritability, weight changes and increased difficulty breathing may be the presenting symptoms.