CARDIOVASCULAR CAUSES OF LOSS OF CONSCIOUSNESS IN PATIENTS WITH PRESUMED EPILEPSY - A CAUSE OF THE INCREASED SUDDEN-DEATH RATE IN PEOPLE WITH EPILEPSY

BACKGROUND, METHODS, AND RESULTS: Syncope and seizures are often indis tinguishable clinically. We present a series of 12 patients diagnosed as having epilepsy. Despite normal or nonspecific electroencephalograp hic findings, 11 of 12 patients were treated or offered treatment with long-term anticonvulsant agents. Subsequently, diagnoses of arrhythmi c or neurally mediated syncope were made in all patients using Bolter monitoring, long-term ambulatory loop electrocardiographic recording, or tilt-table studies. Arrhythmias included torsades de pointes (four patients), atrioventricular nodal reentrant supraventricular tachycard ia (one patient), and sinus arrest (two patients). The remaining five patients had neurally mediated syncope with hypotension and bradycardi a, including asystole in two patients. Treatment for the documented ca rdiovascular abnormalities resulted in the alleviation of syncopal sym ptoms. CONCLUSIONS: Because the observed cardiovascular abnormalities are potentially fatal, this series suggests that undiagnosed cardiac s yncope may contribute to the documented increased sudden death rate in patients with presumed epilepsy. Cardiac causes of loss of consciousn ess should be considered in patients with presumed epilepsy, atypical premonitory symptoms (such as nausea, lightheadedness, or palpitations ), nondiagnostic electroencephalograms, and failure to respond to anti convulsant therapy.