Sudden cardiac arrest in an athlete due to dilated cardiomyopathy masquerading as athlete's heart: a case report.

Background: Sudden cardiac arrest (SCA) in athletes is a rare but catastrophic event, most often associated with underlying cardiac pathology. Differentiating physiological remodeling ("athlete's heart") from pathological conditions such as cardiomyopathy or channelopathy remains a major clinical challenge. Case summary: A 25-year-old professional athlete presented with recurrent syncope and was found to have frequent premature ventricular complexes with polymorphic ventricular tachycardia and prolonged QT interval. She developed cardiac arrest due to torsades de pointes and was successfully resuscitated. Cardiac magnetic resonance imaging revealed a dilated left ventricle with systolic dysfunction and non-ischemic myocardial fibrosis, consistent with dilated cardiomyopathy rather than physiological adaptation. A 24-hour Holter demonstrated frequent multifocal ventricular ectopy. The patient underwent implantable cardioverter-defibrillator implantation for secondary prevention, followed by successful 3D electroanatomical mapping-guided catheter ablation of premature ventricular complexes originating from the right ventricular outflow tract, resulting in suppression of arrhythmia. Conclusion: Early identification of pathological substrates in athletes is crucial, as timely intervention, including ICD implantation and catheter ablation can be life-saving.