HR and QTc increase with ictal activity, whereupon modulation of QTc, but not of HR, is asymmetrically lateralized.

<p>(A) Absolute HR at different timepoints from all patients was averaged (based on a mean HR per timepoint and side of seizure-onset per patient). Paired data for right- (white bars) and left-hippocampal onset (grey bars) were available from all 15 patients at all timepoints. (B) Relative HR changes from all patients were averaged with no significant difference of ictal modulation of HR between left- and right-onset seizures. (C) QT intervals corrected with all four formulas (grey bars, left-hippocampal seizures; white bars, right-hippocampal seizures) were plotted versus three timepoints (1, preictal; 2, unilateral ictal activity; 3, postictal). (D) The absolute ictal changes of QT intervals using all four correction formulas (Ba, Bazett; Fri, Fridericia; Ho, Hodges; Fra, Framingham) were separately plotted for left- (grey bars) and right-hippocampal seizures (white bars). QT lengthening was significantly greater during left-hippocampal activity as assessed with all 4 correction formulas, suggesting an asymmetric ictal modulation of cardiac repolarization. All data expressed as mean±S.E.M.