Abstract
Acute myocarditis is often secondary to an acute virus infection, which can be the first manifestation of upper respiratory tract symptoms, followed by chest tightness, shortness of breath, palpitations, chest pain and other non-specific symptoms. In severe cases, it can quickly progress to serious complications such as heart failure, shock and respiratory failure. Laboratory examinations can show an increase of myocardial injury markers, infection and inflammatory indicators. Cardiac ultrasound can detect the weakening of the myocardial contraction and valve regurgitation. On imaging, bilateral pulmonary oedema demonstrates symmetrical infiltration along the hilum of lung, called the "butterfly shadow". This current case report describes a patient with unilateral pulmonary oedema caused by myocarditis that was initially misdiagnosed and treated as pneumonia. The patient was subsequently treated with the application of extracorporeal membrane oxygenation and he made a full recovery. A review of this case highlights that when a patient's symptoms are not typical, a comprehensive examination and evaluation are required to avoid incorrect treatment.