Gula Lorne J, Trim Geoffrey M, Krahn Andrew D, Skanes Allan C, Yee Raymond, Klein George J
Division of Cardiology, University of Western Ontario, London, Ontario, Canada.
J Interv Card Electrophysiol. 2005 Jan;12(1):69-73. doi: 10.1007/s10840-005-5843-0.
Direct pacing of the His bundle has been proposed for permanent pacing to maintain physiological synchrony of ventricular activation. Measurement of His bundle refractoriness may be useful in predicting suitability of this technique in an individual. We sought to determine whether this could be measured consistently in patients, defining a normal range.
His bundle pacing was performed in 20 consecutive patients (mean age 44.6 +/- 19.5, 5 male) undergoing electrophysiology study. Incremental and extrastimulus testing were performed from the His region to determine effective and functional refractory periods of the His bundle.
Consistent His capture was possible in 18 of 20 (90%) patients studied. Extrastimulus testing from the His region at a drive cycle length of 600 msec was successful in all of these patients. With loss of His capture, QRS duration prolonged 32%, and stimulus to atrial electrogram interval prolonged 49.6 +/-16.3 msec. The effective refractory periods at drive cycle lengths 600, 500, and 400 msec were 407 +/- 70 msec, 320 +/- 39 msec, and 336 +/- 54 msec, respectively. Corresponding functional refractory periods were 414 +/- 62, 371 +/- 52, and 329 +/- 32. Consistent capture with incremental His pacing was possible in 50% of patients, and 1:1 His capture was lost at mean cycle length 408 +/-93 msec.
His refractory periods can be determined consistently in unselected individuals undergoing electrophysiological studies. Measurement of HERP and HFRP may prove useful in assessing the suitability of the His bundle for permanent pacing.
已提出通过直接起搏希氏束进行永久性起搏，以维持心室激动的生理同步性。测量希氏束不应期可能有助于预测该技术在个体中的适用性。我们试图确定在患者中能否一致地测量希氏束不应期，并确定正常范围。
对20例连续接受电生理检查的患者（平均年龄44.6±19.5岁，男性5例）进行希氏束起搏。从希氏束区域进行递增和额外刺激测试，以确定希氏束的有效和功能不应期。
在20例研究患者中的18例（90%）能够持续夺获希氏束。在所有这些患者中，驱动周期长度为600毫秒时从希氏束区域进行额外刺激测试均成功。当失去希氏束夺获时，QRS波时限延长32%，刺激至心房电图间期延长49.6±16.3毫秒。驱动周期长度为600、500和400毫秒时的有效不应期分别为407±70毫秒、320±39毫秒和336±54毫秒。相应的功能不应期分别为414±62、371±52和329±32。50%的患者通过递增希氏束起搏能够持续夺获，在平均周期长度408±93毫秒时失去1:1希氏束夺获。
在未选择的接受电生理检查的个体中可以一致地确定希氏束不应期。测量希氏束有效不应期和功能不应期可能有助于评估希氏束进行永久性起搏的适用性。
