Clinical Electrophysiology -> Ventricular Arrhythmias -> Electrocardiography D-PO05 - Poster Session V (ID 39) Poster

D-PO05-237 - To Study The Prevalence Of Cardiac Channelopathies In Children Aged 5-18 Years Undergoing Treatment For Epilepsy (ID 1323)

 J.S. Gujral: Nothing relevant to disclose.


Background: Cardiac channelopathies, most commonly Long QT syndrome may be misdiagnosed as refractory epilepsy, when in reality, these events represent convulsive syncope.
Objective: The objective of the study was to observe the prevalence of cardiac channelopathies in children aged 5-18 years undergoing treatment for epilepsy.
Methods: All patients aged 5-18 years undergoing treatment for epilepsy at a tertiary care centre in North India and with non-contributory neuroimaging /electroencephalogram were included in the study. Patients with ECG findings suggestive of Long QT syndrome (QTc ≥ 480 ms - prepubertal, ≥ 470 ms - post pubertal males, ≥ 480 ms - post pubertal females, as per Bazett formula), Brugada syndrome (type 1 pattern), short QT syndrome (QTc < 360 ms at heart rate < 100 bpm)/ Arrythmogenic Right Ventricular cardiomyopathy (2010 task force criteria), underwent blood sampling for genetic analysis by whole exome sequencing.
Results: A total of 1000 patients were enrolled in the study. 5 cases suggestive of Long QT syndrome were identified. The mean lag period between symptom onset and final diagnosis was 4 ± 3.1 years. The mean QTc was 500 + 23 ms and the mean Schwartz score was 4.8 + 1.3. Of them, 3/5 had a history of syncope, which was exertional in 2 patients. The seizure semiology was generalized tonic clonic seizures in most of the cases (3/5). One of the patients also had congenital bilateral sensorineural hearing loss. T wave alternans and exercise induced polymorphic ventricular tachycardia was observed in one patient each. All patients were started on oral propranolol therapy (weight based) and one of the patients was advised permanent pacemaker implantation. All the patients remained seizure free for the mean duration of follow up (8 months). Antiepileptics were tapered off in all patients except the one with left focal seizures. The results of whole exome sequencing are available for 3 of the patients out of which a de-novo heterozygous variant with damaging effect (c.950A>G) was found in exon 7 of KCNQ1 gene in one of the patients suggestive of Long QT syndrome type 1.
Conclusion: A 12-lead electrocardiogram should be sought in all patients presenting with seizures of unknown causation especially children.