Cardiac repolarization indices in epilepsy patients

Objectives: Although epilepsy may be associated with an increased risk for sudden cardiac death, its effects on Q-T intervals has not been established. Methods: To determine whether changes in Q-T interval duration (QT _{max c}, QT_{min c}) and dispersion (QT_{D c}) occur in epileptic patients, we retrospectively studied 40 consecutive patients (age: 36.1 ± 22.2 years) who have had a seizure disorder for 14.0 ± 12.2 years and were seen in the Epilepsy Monitoring Unit, and 60 age-matched non-epileptic controls (age: 38.0 ± 15.6 years). Q-T intervals were calculated from a single 12-lead ECG. Results: QT_{max c} (425 ± 30 vs. 410 ± 36 ms, p = 0.040) and QT_{D c} (63.1 ± 22.4 vs. 31.0 ± 17.2 ms, p = 0.000) were higher, and QT_{min c} (362 ± 36 vs. 379 ± 33 ms, p = 0.040) was lower in epilepsy patients. QT_{max c} was significantly correlated with disease duration (r = -0.35, p = 0.028) before, but not after age correction (r = -0.31, p = 0.053). Neither age nor reported recent seizure frequency was correlated with any repolarization index. Conclusions: QT_{max c} and QT_{D c} are higher in epilepsy patients as compared to control subjects. While Q-T interval appears to be related to disease duration, particularly over the early history of disease, it is unrelated to patient age or recent reported seizure frequency.