[Background - Sudden death appears in 8-17% of epilepsy patients non-responding to antiepileptic therapy. Some studies suggest that the most common cause of death is seizure-related cardiac arrhythmia. Aim of study - To analyze the alteration of the heart rate six hours before and after the seizures. Methods - Eighteen patients suffering from focal epilepsy were examined before epilepsy surgery. Video-EEG-ECG was carried out for 2-10 days, and 32 seizures were registered. Analysis of the heart rate was based on the 5- minute-long epochs of the ECGs taken at the 5-10-15- 30th minutes and at the 1-3-6th hours before and after seizures. Results - The heart rate increases (from average 69 beats/min to 92 beats/min, p<0.001) immediately after seizures, tough significantly higher heart rate was observed 3 hours after seizures. There were no patients with severe periictal bradycardia. In one of our patients, ectopic cardiac rhythm occurred after a generalized tonicclonic seizure. Conclusions - We can conclude that the sympathic activity increases while the parasympathic activity decreases after seizures. The observed alterations lasted for a long time and predict to fatal arrhythmias. These suggest that sudden death in epilepsy can be induced by cardiac arrhythmias connected with epileptic seizures.]