A 14-year-old girl with recurrent episodes of transient loss of consciousness (T-LOC) during physical activities was presented to our hospital accompanied by her mother. She was started on lamotrigine on suspicion of epilepsy. Further investigations were conducted since there was no improvement. e electrophysiology study was normal, but the cardiac computed tomography (CT) showed an abnormal origin of the right coronary artery, which was interarterial (running between the aorta and pulmonary artery but had no intramural course). e exercise stress test revealed no evidence of myocardial ischemia. Electroencephalography (EEG) ndings were atypical, and the T-LOC episodes during physical activity, which are rare in epileptic seizures, made it di cult to di erentiate between cardiogenic syncope and epilepsy. erefore, an insertable cardiac monitor (ICM) was implanted. A er implantation, the ICM recordings showed that the T-LOC episodes were not accompanied by any arrhythmias. However, electromyography (EMG) activity was suspicious of a seizure. Based on these results and the clinical ndings, we concluded that the T-LOC was due to focal to bilateral tonic-clonic seizures (FBTCS), and concomitant use of lacosamide helped in marked relief of the patientʼs symptoms. ICM proves to be e ective in children with T-LOC that is di cult to diagnose.