Purpose: This study assessed the frequency and character of ictal cardiac rhythm and conduction abnormalities in intractable epilepsy. Sudden unexpected death in epilepsy (SUDEP) is a major cause of excess mortality in people with refractory epilepsy, and cardiac arrhythmias during seizures may be responsible. The frequency of cardiac abnormalities during seizures in patients with refractory epilepsy must be determined.
Methods: Fifty-one seizures in 43 patients with intractable partial epilepsy were analyzed prospectively from CCTV-EEG monitoring with one ECG channel. Arrhythmias, repolarization abnormalities, and PR and QTc intervals were determined for preictal (3 min), ictal, and postictal (3 min) periods for one or more seizures per patient. Parametric statistics were used for continuous variables, and nonparametric statistics were used for categoric variables.
Results: Of the patients, 39% had one or more abnormalities of rhythm and/or repolarization during or immediately after seizures. Abnormalities included asystole (one), atrial fibrillation (one), marked or moderate sinus arrhythmia (six), supraventricular tachycardia (one), atrial premature depolarizations (APDs; eight), ventricular premature depolarizations (VPDs; two), and bundle-branch block (three). Mean seizure duration was longer in patients with abnormalities than in those without (204 vs. 71 s; p < 0.001). Generalized tonic-clonic seizures were also associated with increased occurrence of ictal ECG abnormalities (p = 0.006) as compared with complex partial seizures. There were no clinically significant differences in mean preictal and ictal/postictal PR and QTc intervals.
Conclusions: Cardiac rhythm and conduction abnormalities are common during seizures, particularly if they are prolonged or generalized, in intractable epilepsy. These abnormalities may contribute to SUDEP.