An Adult Arrhythmia in a Child’s Heart: A Case Report of Unexplained Atrial Fibrillation

<b>Background and Clinical Significance</b>: Atrial fibrillation is a rare disorder in the pediatric population in the absence of underlying heart disease. A specific arrhythmia, known as lone pediatric atrial fibrillation, can occur without identifiable structural heart abnormalities. <b>Case Presentation:</b> We report a case of a 12-year-old obese child with symptomatic hypertension and atrial fibrillation diagnosed through an electrocardiogram (ECG). <b>Conclusions:</b> The patient was rapidly managed with intravenous metoprolol, and he subsequently started cardiologic treatment and clinical follow-up. This case underlines the possibility of performing routine ECGs in the follow-up of obese children.