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.