Antiepileptic drugs can induce changes in the electrocardiograph (ECG) records including prolongation of QT interval but there is no evidence to link this effect with the sudden death that reported in epilepsy. The new generations of antiepileptic drugs showed variable effect on the heart. Lamotrigine did not prolonged the QT interval in healthy subjects while levetiracetam prolonged the QT interval in patients cardiac channelopathy presented with congenital long QT syndrome.
This study aimed to investigate effects of antiepileptic drugs that prescribed in a therapeutic regimen to new cases of epilepsy as a part of management on the ECG records at the end of the 1st three months of treatment.
PATIENTS AND METHODS:
A total number of 25 patients, presented for the first time with epilepsy, were recruited from Al-Yarmouk Teaching hospital. Each patient was assessed clinically by consultant neurology prior to enrollment in the study. An electrocardiogram (ECG) was obtained at the time of entry into the study prior to the admission of the study and after three months of treatment with antiepileptic drugs. In addition to the measurements of heart rate and different ECG intervals, a QT-nomogram and cardiac restitution were used in analysis.
At the time of entry, three patients had a significant short corrected QT interval (QTcB); four patients had a borderline QTcB interval; and one patient had prolonged QTcB interval. QT-nomogram revealed that many patients have abnormal interval and antiepileptic drugs significantly reduced the relaxation phase of cardiac cycle and prolonged the ventricular repolarization.
Antiepileptic drugs carried a harmful effect on the heart and their assessment should be not restricted in the measurement of QT interval before and after treatment or to study their effects on the healthy subject as epilepsy is commonly associated with mutation of sodium and/or potassium channels. Case finding of significant prolonged QT interval in respect to gender and age, assessment of QT nomogram and cardiac restitution are useful tools to identify the patients who are at risk of arrhythmias.