Hidden Cardiac Channelopathies in Children Presenting with Syncope and Seizure-like Events

Background: Cardiac channelopathies are rare but potentially life-threatening disorders that may present with syncope or seizure-like episodes in children, often leading to misdiagnosis and delayed recognition. Other arrhythmia-associated cardiac conditions may also present with similar clinical manifestations and require careful cardiac evaluation. Objective: To evaluate the prevalence of cardiac channelopathies and inherited arrhythmogenic cardiac disorders in pediatric patients presenting with syncope and seizure-like events and to identify associated clinical and electrocardiographic features. Methods: This retrospective cross-sectional study included pediatric patients presenting with syncope, presyncope, seizures, or seizure-like episodes who underwent cardiac evaluation at Ankara Dr. Sami Ulus Maternity and Children's Health and Diseases Training and Research Hospital between January 2015 and April 2019. Cardiac evaluation was performed using a standard 12-lead electrocardiogram and was complemented by additional investigations, including 24 h Holter monitoring, exercise testing, pharmacological provocation, electrophysiological studies, and genetic analysis, when clinically indicated. Demographic, clinical, and diagnostic parameters were systematically evaluated. Results: A total of 363 patients were included in the final analysis. The mean age was 12.2 ± 4.7 years, and 58.7% were female. The most common diagnosis was vasovagal syncope (n = 160, 44.1%), followed by epilepsy (n = 53, 14.6%). Cardiac channelopathies, and arrhythmogenic right ventricular dysplasia (ARVD) were identified in 18 patients, corresponding to 4.9% of the pediatric cardiology-evaluated patients and 0.82% of the initial screened population. These diagnoses included long QT syndrome (n = 8), Brugada syndrome (n = 3), short QT syndrome (n = 3), catecholaminergic polymorphic ventricular tachycardia (n = 2), ARVD (n = 1), and malignant-type early repolarization (n = 1). Compared with other patients, those with cardiac channelopathies, malignant-type early repolarization, and ARVD more frequently had exercise-related triggers (p < 0.001), ventricular extrasystoles and ventricular tachycardia (p < 0.001), and abnormal exercise test findings (p < 0.001). Conclusions: Cardiac channelopathies are not uncommon in pediatric patients presenting with syncope and seizure-like events and should be considered in the differential diagnosis. Clinical triggers, family history, and electrocardiographic abnormalities may serve as important clues for early identification. A multidisciplinary approach, including detailed cardiac evaluation, is essential to prevent misdiagnosis and reduce the risk of sudden cardiac death.