Signal-averaged and standard electrocardiography in patients with newly diagnosed epilepsy

Antiepileptic drugs (AEDs) have been associated with cardiac conduction abnormalities and arrhythmias, predominantly in patients with predisposing cardiac conditions. Ventricular late potentials (VLPs) detected in the signal-averaged electrocardiogram (SAECG) may imply an increased risk of ventricular tachycardia or fibrillation. Twenty-six AED-naïve patients with newly diagnosed epilepsy and no clinical evidence of heart disease were examined with SAECG and standard ECG. Fifteen patients were treated with lamotrigine and ten with carbamazepine. No significant abnormality was found in the standard ECG or SAECG three to nine months after initiation of AED therapy. In one patient, a VLP was detected at baseline and subsequent MRI demonstrated significant right ventricular pathology; therefore, this patient was excluded from the rest of the study. This exclusion along with only newly diagnosed patients with a low total seizure count being included in the study may explain the lack of AED-induced electrocardiographic abnormalities in this patient cohort.