Young M L
Department of Pediatrics, National Taiwan University, Taipei.
Pacing Clin Electrophysiol. 1990 Dec;13(12 Pt 1):1666-73. doi: 10.1111/j.1540-8159.1990.tb06869.x.
By using extrastimulation technique the effective refractory period (ERP) of the atrioventricular (AV) node is conventionally defined as the longest A1A2 interval at which conduction of A2 is blocked within the node. With the prolongation of the AV nodal transit time that is associated with this technique, the delayed AV nodal arrival of the A1 impulse will cause an overestimation of the true interval if the A1A2 interval is used as the gauge. Under this condition, the conventional approach will not accurately delineate the ERP of the AV node. However, this prolongation of the nodal transit time can be calculated by subtracting the basal conduction time from the conducted A-H interval. By subtracting out the prolongation from the longest A1A2 at which A2 impulse is blocked, not only an interval more indicative of the true AV nodal ERP can be obtained, but also the apparent discrepancies between the in vitro and human AV nodal recovery curves disappear.
通过使用额外刺激技术，房室（AV）结的有效不应期（ERP）传统上被定义为A2在结内传导被阻滞时的最长A1A2间期。随着与该技术相关的房室结传导时间延长，如果将A1A2间期用作衡量标准，A1冲动延迟到达房室结会导致对真实间期的高估。在这种情况下，传统方法无法准确描绘房室结的ERP。然而，房室结传导时间的这种延长可以通过从传导的A-H间期减去基础传导时间来计算。通过从A2冲动被阻滞的最长A1A2间期中减去这种延长，不仅可以获得更能指示真实房室结ERP的间期，而且体外和人体房室结恢复曲线之间的明显差异也会消失。
