Middlekauff H R, Stevenson W G, Klitzner T S
Department of Medicine, UCLA School of Medicine 90024-1679.
Pacing Clin Electrophysiol. 1990 Dec;13(12 Pt 1):1629-36. doi: 10.1111/j.1540-8159.1990.tb06865.x.
Intermittent preexcitation in the Wolff-Parkinson-White syndrome has been equated with a long accessory pathway refractory period and long R-R interval between preexcited beats in atrial fibrillation and therefore a low risk for sudden death. A case of Wolff-Parkinson-White syndrome in which preexcitation became intermittent following procainamide infusion, with only moderate prolongation of the accessory pathway refractory period but marked prolongation of the shortest preexcited R-R interval in atrial fibrillation, is described. Programmed ventricular and atrial stimulation demonstrated that intermittent preexcitation was caused by concealed conduction producing a linking phenomenon, facilitated by the antiarrhythmic drug. Linking due to concealed retrograde penetration of a propagated impulse into the accessory pathway may contribute to the disparity between accessory pathway refractory period and shortest preexcited R-R interval in atrial fibrillation in some patients and may be a confounding factor in the interpretation of noninvasive tests of accessory pathway conduction.
预激综合征中的间歇性预激被认为与旁路不应期长以及房颤时预激搏动之间的R-R间期长有关，因此猝死风险较低。本文描述了1例预激综合征患者，静脉输注普鲁卡因胺后预激变为间歇性，旁路不应期仅中度延长，但房颤时最短预激R-R间期显著延长。程控心室和心房刺激显示，间歇性预激是由隐匿性传导产生的连接现象所致，抗心律失常药物促进了这种现象。在某些患者中，由于前传冲动隐匿性逆行穿入旁路导致的连接可能导致房颤时旁路不应期与最短预激R-R间期之间的差异，并且可能是解释旁路传导无创检查结果时的一个混杂因素。
