Proctor E E, Leman R B, Mann D L, Kaiser J, Kratz J, Gillette P
Department of Medicine, Medical University of South Carolina, Charleston 29425.
Am Heart J. 1991 Sep;122(3 Pt 1):728-32. doi: 10.1016/0002-8703(91)90518-m.
Previous studies have shown that single-chamber sensor-driven pacing improves exercise tolerance for patients with chronotropic incompetence. However, long-term single-chamber pacing has a number of inherent problems that limit its usefulness. Although sensor-driven dual-chamber pacing largely obviates the problems inherent with single-chamber sensor-driven pacing, the physiologic benefit of dual-chamber sensor-driven pacing has not yet been demonstrated. Accordingly, the purpose of this study was to compare exercise-induced cardiac output for patients with chronotropic incompetence, after programming their pacemakers to either a simulated sensor-driven single or simulated dual-chamber mode. Cardiac output was measured noninvasively at rest and peak exercise using standard Doppler-derived measurements, obtained in a blinded fashion. At rest the Doppler-derived resting VVI and DDD cardiac outputs were 4.49 +/- 0.3 L/min and 4.68 +/- 0.3 L/min, respectively. At peak exercise, the DDD cardiac output was 5.07 +/- 0.5 L/min, whereas the simulated activity VVI and DDD cardiac outputs were 6.33 +/- 0.6 L/min and 7.41 +/- 0.70 L/min, respectively. Analysis of variance showed that there was an overall significant difference in cardiac output from rest to peak exercise (p less than 0.001). However, only the simulated activity DDD cardiac output was significantly different from its respective control value (p less than 0.05). Thus this study shows for the first time that the addition of rate responsiveness to dual-chamber pacing results in a significant improvement in cardiac output for patients with chronotropic incompetence.
先前的研究表明，单腔传感器驱动起搏可提高变时性功能不全患者的运动耐量。然而，长期单腔起搏存在许多固有问题，限制了其效用。尽管传感器驱动双腔起搏在很大程度上消除了单腔传感器驱动起搏固有的问题，但双腔传感器驱动起搏的生理益处尚未得到证实。因此，本研究的目的是比较变时性功能不全患者在将起搏器编程为模拟传感器驱动单腔或模拟双腔模式后的运动诱导心输出量。使用标准多普勒衍生测量方法，以盲法在静息和运动峰值时无创测量心输出量。静息时，多普勒衍生的静息VVI和DDD心输出量分别为4.49±0.3L/分钟和4.68±0.3L/分钟。运动峰值时，DDD心输出量为5.07±0.5L/分钟，而模拟活动VVI和DDD心输出量分别为6.33±0.6L/分钟和7.41±0.70L/分钟。方差分析表明，从静息到运动峰值，心输出量存在总体显著差异（p<0.001）。然而，只有模拟活动DDD心输出量与其各自的对照值有显著差异（p<0.05）。因此，本研究首次表明，双腔起搏增加频率反应性可使变时性功能不全患者的心输出量显著改善。
