Persistent Cardiac Magnetic Resonance Imaging Features of Myocarditis Detected Months After COVID-19 Infection

Acute myocarditis is commonly caused by viral infections resulting from viruses such as adenovirus, enteroviruses, and, rarely, coronavirus. It presents with nonspecific symptoms like chest pain, dyspnea, palpitation, or arrhythmias and can progress to dilated cardiomyopathy or heart failure. Fulminant myocarditis is a potentially life-threatening form of the condition and presents as acute, severe heart failure with cardiogenic shock. In this report, we discuss a case of a 41-year-old female who presented with cough and chest pain of two days' duration. The patient had a new-onset atrial flutter. Her chest auscultation revealed bilateral crackles. Laboratory workup revealed elevated troponin levels, and the patient tested positive for coronavirus disease 2019 (COVID-19) by nasopharyngeal swab polymerase chain reaction (PCR). Transthoracic echocardiogram revealed a low left ventricular (LV) ejection fraction of 35-40% compared to 55% one year prior, as well as a granular appearance of LV myocardium. The patient's condition subsequently improved clinically and she was discharged home. Due to cardiac involvement and characteristic myocardial appearance on the echocardiogram, cardiac magnetic resonance (CMR) imaging was performed for further evaluation about two months from the date of admission. CMR showed extensive myocardial inflammation with a typical pattern of sub-epicardial and mid-wall delayed enhancement, confirming the diagnosis of myocarditis. This case highlights myocarditis as a potential complication of COVID-19 that requires early diagnosis and proper management to improve patients' quality of life. Additionally, we highlight the features of myocarditis on CMR in the acute phase and two months after clinical recovery.