Mumps Myocarditis Documented by Cardiac Magnetic Resonance Imaging in a Vaccinated Teen

Abstract This case report details a rare instance of mumps myocarditis in a fully vaccinated 13-year-old female, who presented with fever, parotid swelling, and signs of heart failure. Investigations revealed elevated cardiac biomarkers, complete heart block, and echocardiographic abnormalities. Cardiac magnetic resonance imaging showed hypokinesia and late gadolinium enhancement in the lateral segments, confirming the diagnosis of myocarditis. The patient was treated with supportive care, including diuretics, and discharged on angiotensin-converting enzyme inhibitors and aldosterone antagonists. Follow-up showed normalization of cardiac function. This case underscores the possibility of mumps myocarditis even in vaccinated individuals, emphasizing the importance of considering myocarditis in similar clinical scenarios.