RESUMO
We present the case of a previously healthy 14-year-old boy who experienced two episodes of lightheadedness while sitting under the sun. The patient did not experience syncope and denied experiencing any other symptoms. Moreover, he exhibited great functional capacity. An electrocardiogram showed T-wave inversions in leads V1 to V4. Subsequent echocardiogram and cardiac magnetic resonance imaging confirmed the diagnosis of arrhythmogenic cardiomyopathy with severe features. Arrhythmogenic cardiomyopathy is a disorder characterized by fibrofatty degeneration of the myocardium and is a common cause of sudden cardiac death. This case highlights the significance of early investigation in any child who presents with seemingly benign symptoms, as they may be indicative of a serious cardiac disease.