Atrial fibrillation in a child with multisystem inflammatory syndrome in children.

Atrial fibrillation (AF) is a rare complication of multisystem inflammatory syndrome in children (MIS-C) associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. A 10-year-old boy with a history of SARS-CoV-2 infection 10 weeks before presentation developed AF following the onset of MIS-C. The patient presented with high fever, conjunctival congestion, erythematous throat, and a diffuse erythematous macular rash involving the face and both legs, in addition to respiratory distress and shock requiring oxygen and vasopressor support. Echocardiography revealed poor left ventricular contractility and normal-appearing coronary vessels. The patient received intravenous immunoglobulin, pulse methylprednisolone, and aspirin. AF resolved with synchronized cardioversion and the patient's clinical condition subsequently improved. This case reports a rare phenomenon of AF in a case of MIS-C. Further research is required to verify the association.