Lehmann M H, Mahmud R, Denker S, Soni J, Akhtar M
Circulation. 1984 Sep;70(3):392-401. doi: 10.1161/01.cir.70.3.392.
Although concealed conduction in the atrioventricular node (AVN) has been the focus of numerous experimental and clinical studies, little is known about the differential effects on AVN functional behavior of prior concealed retrograde impulse penetration alone vs prior anterograde or dual AVN activation. This study was undertaken specifically to investigate this aspect of human AVN physiology in patients without intact ventriculoatrial conduction to provide a model with which to analyze concealed retrograde AVN conduction. In 13 such patients AVN behavior during a subsequent anterograde input was characterized for each of three different manners of prior AVN activation: anterograde alone (method I), simultaneous anterograde and retrograde excitation (method II), or equivalently timed retrograde concealed AVN penetration alone (method III). In all patients evidence for retrograde AVN concealment was documented by longer anterograde conduction in the AVN during method III than that observed when the retrograde impulse was omitted (method IV). Furthermore, in these patients lacking intact ventriculoatrial conduction, anterograde conduction in the AVN was facilitated and refractoriness was decreased during dual excitation vs anterograde activation alone (method II vs method I). However, when each of methods I and II were compared with concealed retrograde AVN penetration alone (method III), two patterns of AVN responses were observed: In 11 of 13 patients (group A) conduction in the AVN was "worse" and refractoriness was greater both in methods I and II compared with method III; in the remaining two patients (group B) the opposite relationships were observed. The results suggest that among patients with no ventriculoatrial AVN conduction there exist at least two subpopulations whose AVN functional characteristics differ markedly when the effects of anterograde and dual excitation are compared with equivalently timed concealed retrograde activation alone. These findings may be related to differences in level of retrograde AVN concealment in groups A and B, which can be unmasked by the outlined pacing techniques.
尽管房室结（AVN）的隐匿性传导一直是众多实验和临床研究的焦点，但对于单纯先前隐匿性逆行冲动穿透与先前顺行或双房室结激活对房室结功能行为的差异影响却知之甚少。本研究专门针对无完整室房传导的患者，研究人体房室结生理学的这一方面，以提供一个分析隐匿性逆行房室结传导的模型。在13例此类患者中，针对三种不同的先前房室结激活方式，分别对随后顺行输入时的房室结行为进行了特征描述：单纯顺行（方法I）、顺行和逆行同时激动（方法II）或等效定时的单纯逆行隐匿性房室结穿透（方法III）。在所有患者中，通过方法III期间房室结中较长的顺行传导记录到逆行房室结隐匿的证据，该传导时间长于省略逆行冲动时观察到的传导时间（方法IV）。此外，在这些缺乏完整室房传导的患者中，与单纯顺行激活相比，双激动期间房室结的顺行传导得到促进，不应期缩短（方法II与方法I）。然而，当将方法I和II分别与单纯逆行隐匿性房室结穿透（方法III）进行比较时，观察到两种房室结反应模式：13例患者中的11例（A组），与方法III相比，方法I和II中的房室结传导“更差”，不应期更长；在其余2例患者（B组）中，观察到相反的关系。结果表明，在无室房房室结传导的患者中，至少存在两个亚组，当将顺行和双激动的影响与等效定时的单纯逆行隐匿性激活进行比较时，其房室结功能特征存在明显差异。这些发现可能与A组和B组中逆行房室结隐匿程度的差异有关，这些差异可通过所述的起搏技术揭示出来。
