Abstracts

Symptoms of heart disease affecting the level of consciousness is sometimes very difficult to distinguish from epilepsy. Even when the anamnestic information is good and all supplementary tests are performed, uncertainty may still exist. Furthermore, some antiepileptic drugs may affect cardiac electrophysiology which might lead to malignant arrhythmias. The aim of the study was to investigate the relationship between cardiac diseases, epilepsy and antiepileptic drugs (AEDs), using new methods for evaluating cardiac electrophysiology before and after the introduction of AEDs. Twenty-six patients aged 20-60 years (mean age 32 years; 19 women, 7 men) with newly diagnosed epilepsy, were consecutively included. No patients used AEDs before inclusion, and they had no known heart disease. The patients received either carbamazepine (n=10) or lamotrigine (n=15). Blood parameters (electrolytes, creatinine, SR, Hb, thrombocytes and leucocytes) were analysed, and a 12-channel ECG and signal averaged ECG (for identification of ventricular late potentials) were performed before initiation of the AED treatment and after 3-9 months. One female patient had episodes with unconsciousness, generalized seizures and involuntary voiding. EEG showed epileptic activity, while cerebral MRI and resting ECG were normal. However, positive late potentials suggested right ventricular dysplasia, which was confirmed by cardiac MRI. This patient was not included in the rest of the study. All blood parameters including antiepileptic drug levels were within normal/therapeutic range. The serum electrolytes remained unchanged. Neither heart rate, PR interval, QRS- and QT-duration and the appearance of the T waves nor the parameters in signal averaged ECG were changed by AED treatment. However, one 20 years old female patient developed positive late potentials after introduction of lamotrigine. She is referred to further examinations in the department of cardiology. This study illustrates that serious cardiac diseases in epileptic patients may remain undiagnosed if not examined properly. Changes in signal averaged ECG with development of late potentials was found in one patient after introduction of lamotrigine, but significant arrhythmic events were not observed in this limited study group. All epilepsy patients should have an ECG examined by a cardiologist, and in certain cases specialised investigations may be helpful.