Mann D E, Reiter M J
Division of Cardiology, University of Colorado Health Sciences Center, Denver 80262.
Am J Cardiol. 1988 Sep 1;62(7):408-12. doi: 10.1016/0002-9149(88)90968-x.
The electrophysiologic effects of upright posture (45 degrees upright tilt) were studied in 17 patients with dual atrioventricular (AV) nodal pathways, AV nodal reentry or both. Discontinuous AV nodal conduction curves were observed in 16 patients while supine, but in only 11 patients while upright. Fast pathway refractoriness was shortened: the anterograde fast pathway effective refractory period decreased from 360 +/- 22 to 275 +/- 14 ms (mean +/- standard error of the mean), the anterograde fast pathway block cycle length shortened from 448 +/- 28 to 348 +/- 20 ms and the retrograde fast pathway block cycle length shortened from 425 +/- 29 to 338 +/- 24 ms (all p less than 0.01). The anterograde slow pathway block cycle length shortened from 378 +/- 29 to 316 +/- 17 ms (p less than 0.05). AV nodal reentrant tachycardia was induced in 5 patients while supine (2 sustained, 3 nonsustained) and in 6 patients while upright (4 sustained, 2 nonsustained). Tachycardia cycle length shortened during upright posture, from 413 +/- 30 to 345 +/- 22 ms (p less than 0.01), primarily due to shortened anterograde slow pathway conduction time, from 322 +/- 23 to 268 +/- 20 ms (p less than 0.05). Upright posture thus enhances conduction in patients with dual AV nodal pathways, facilitating AV nodal reentry. Electrophysiologic testing in the upright position may yield additional clinical important information in patients with dual AV nodal pathways.
对17例存在双房室（AV）结径路、房室结折返或两者兼有的患者，研究了直立姿势（45度直立倾斜）的电生理效应。仰卧位时，16例患者观察到不连续的房室结传导曲线，而直立位时仅11例患者观察到。快径路不应期缩短：前向快径路有效不应期从360±22毫秒降至275±14毫秒（均值±均值标准误），前向快径路阻滞周长从448±28毫秒缩短至348±20毫秒，逆向快径路阻滞周长从425±29毫秒缩短至338±24毫秒（均p<0.01）。前向慢径路阻滞周长从378±29毫秒缩短至316±17毫秒（p<0.05）。仰卧位时5例患者诱发了房室结折返性心动过速（2例持续性，3例非持续性），直立位时6例患者诱发了该心动过速（4例持续性，2例非持续性）。直立姿势时心动过速周长缩短，从413±30毫秒降至345±22毫秒（p<0.01），主要是由于前向慢径路传导时间缩短，从322±23毫秒降至268±20毫秒（p<0.05）。因此，直立姿势可增强双房室结径路患者的传导，促进房室结折返。对双房室结径路患者进行直立位电生理检查可能会得出更多具有临床重要性的信息。
