Saoudi N, Bellefleur J P, Letac B, Castellanos A
Arch Mal Coeur Vaiss. 1987 Feb;80(2):220-4.
A recent review of the literature corroborated that several factors explained why supraventricular impulses falling gradually earlier in the cycle could traverse the His-Purkinje system while other impulses occurring later could fail to do so. The present report deals with the coexistence (in the same patient) of three distinct mechanisms whereby progressively more premature impulses could be "unexpectedly" conducted. Phase III left bundle branch block coexisted with the following conduction disturbances in the right bundle branch; late "pseudosupernormal" conduction sandwiched in between periods of phase III and phase IV block; intermediate "pseudosupernormal" conduction resulting from the so-called type 2 gap, during which propagation occurred, but with H-V intervals longer than later in the cycle; early "true" supernormal conduction (related temporarily to the end of the T wave) exposed when a premature ventricular beat reached the affected zone in a concealed retrograde fashion. These findings show how, with block late in the cycle, conduction in earlier part of the cycle was not always due to "true" supernormal conduction.
最近一项文献综述证实，有几个因素可以解释为何在心动周期中逐渐提前出现的室上性冲动能够通过希氏-浦肯野系统，而其他较晚出现的冲动却不能。本报告探讨了（同一患者体内）三种不同机制并存的情况，通过这三种机制，越来越提前的冲动能够“意外地”发生传导。III期左束支传导阻滞与右束支的以下传导障碍并存：在III期和IV期阻滞期间夹有晚期“假性超常”传导；由所谓的2型间隙导致的中间“假性超常”传导，在此期间发生传导，但H-V间期比心动周期后期更长；当室性早搏以隐匿性逆行方式到达受影响区域时暴露的早期“真正”超常传导（暂时与T波结束相关）。这些发现表明，在心动周期后期出现阻滞时，心动周期早期的传导并不总是由于“真正”的超常传导。
