日本小児循環器学会雑誌 Pediatric Cardiology and Cardiac Surgery

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. The 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). The exercise stress test revealed no evidence of myocardial ischemia. Electroencephalography (EEG) findings were atypical, and the T-LOC episodes during physical activity, which are rare in epileptic seizures, made it difficult to differentiate between cardiogenic syncope and epilepsy. Therefore, an insertable cardiac monitor (ICM) was implanted. After 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 findings, 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 patient’s symptoms. ICM proves to be effective in children with T-LOC that is difficult to diagnose.