Darbin O, Casebeer D, Naritoku D K
Department of Neurology, Southern Illinois University School of Medicine, P.O. Box 19637, Springfield, USA.
Exp Neurol. 2003 Jun;181(2):327-31. doi: 10.1016/s0014-4886(03)00112-2.
Convulsive seizures triggered by maximal electroshock (MES) induce profound abnormalities in neural regulation of cardiac rhythm that are manifested by a period of marked cardiac arrhythmia in the immediate postictal state. It is not known whether seizure severity or seizure experience may influence the duration of cardiac arrhythmia in the postictal state. We varied the duration of MES administered to rats to vary seizure severity, as measured by the extensor to flexion (E/F) ratio. In separate experiments, rats were subjected to daily MES. Finally, we pretreated rats with ketamine prior to MES to block seizures hindlimb extension. In all animals, the R-R interval was plotted on the tachogram, and the duration of the arrhythmia was measured. Increases in MES duration increased significantly the E/F ratio and prolonged significantly the postictal cardiac arrhythmia. Repetition of MES caused a kindling effect with respect to seizure severity resulting in a significant increase of the E/F ratio and significant increases in the duration of postictal arrhythmia. Blocking of the hindlimb extension by ketamine abolished arrhythmia suggesting that the arrhythmia is not caused directly by MES. Severity of tonic convulsive seizures is a determinant of disordered cardiac autonomic regulation and directly influences the duration of cardiac arrhythmia during the immediate postictal state following MES. Seizure repetition also increases abnormalities of postictal neural regulation of the heart, but further studies are needed to determine whether this effect is independent of seizure severity increases.
最大电休克（MES）引发的惊厥性癫痫发作会在心律的神经调节方面诱发严重异常，这表现为发作后即刻出现一段明显的心律失常期。目前尚不清楚癫痫发作的严重程度或发作经历是否会影响发作后心律失常的持续时间。我们改变给予大鼠的MES持续时间以改变癫痫发作的严重程度，通过伸肌与屈肌（E/F）比值来衡量。在单独的实验中，让大鼠每日接受MES。最后，我们在MES之前用氯胺酮预处理大鼠以阻断癫痫发作时后肢的伸展。在所有动物中，将R-R间期绘制在心动图上，并测量心律失常的持续时间。MES持续时间的增加显著提高了E/F比值，并显著延长了发作后心律失常的时间。重复进行MES会在癫痫发作严重程度方面产生点燃效应，导致E/F比值显著增加以及发作后心律失常持续时间显著延长。氯胺酮对后肢伸展的阻断消除了心律失常，这表明心律失常并非由MES直接引起。强直性惊厥发作的严重程度是心脏自主神经调节紊乱的一个决定因素，并直接影响MES后即刻发作后心律失常的持续时间。癫痫发作的重复也会增加发作后心脏神经调节的异常，但需要进一步研究来确定这种效应是否独立于癫痫发作严重程度的增加。
