The importance of the electrocardiogram in ambulatory electroencephalographic recordings.

The role of an ambulatory electroencephalogram performed simultaneously with an electrocardiogram was studied in 861 neurologic inpatients. In total, 123 patients (14%) had interictal cardiac rhythm abnormalities, and 31 (4%) had neurologic symptoms considered to be of cardiac origin. The occurrence of cardiac arrhythmias was related to medical history of cardiovascular disease, but not to organic cerebral disorders. The ictal increase of heart rate was significantly higher and more abrupt in epileptic seizures than in psychogenic attacks. The ictal electroencephalogram/electrocardiogram may thus be applicable to the differential diagnosis between the epileptic and psychogenic seizures.