Acute Myocarditis Secondary to Paediatric Inflammatory Multisystem Syndrome Temporally Associated With COVID-19 Infection

A 17-year-old female, who was previously fit and well with no preexisting health conditions, presented with a four-day history of worsening shortness of breath and diarrhoea. She had recent close contact with a relative diagnosed with COVID-19. On clinical examination, she was drowsy, hypotensive, tachycardic, tachypnoeic, and pyrexial. Her blood tests showed elevated inflammatory markers and lymphopenia. She underwent a transthoracic echocardiogram, which confirmed a severely impaired left ventricular (LV) systolic function with an ejection fraction of 35%. An initial impression of acute viral myocarditis was made. Three separate polymerase chain reaction (PCR) tests for SARS-CoV-2 RNA were performed, but they all returned negative. The patient was not responding to initial therapy. Therefore, the regional paediatrics hospital was consulted, and a diagnosis of paediatric inflammatory multisystem syndrome temporally associated with COVID-19 (PIMS-TS) was made, based on similar regional presentations. The patient was administered IV immunoglobulin therapy, to which she responded very well. Following a five-day hospital stay, the patient was discharged home as medically stable. A repeat transthoracic echocardiogram (TTE) showed recovery of the LV systolic function to 62%. Few cases have been reported on myocardial involvement in young patients with PIMS-TS. This case report highlights the initial presentation, medical care, and clinical course of this patient.