Lau C P, Tai Y T, Fong P C, Li J P, Leung S K, Chung F L, Song S
Department of Medicine, University of Hong Kong, Queen Mary Hospital.
Pacing Clin Electrophysiol. 1992 Mar;15(3):334-43. doi: 10.1111/j.1540-8159.1992.tb06503.x.
The rate adaptive characteristics and pacemaker mediated tachycardia protection algorithm of an accelerometer based DDDR pacemaker were evaluated in 11 patients with bradycardia (seven atrioventricular block, four sick sinus syndrome). Rate adaptive programming was effected by collecting the acceleration level during a 3-minute moderate exercise ("tailoring" of sensor). In comparison with an externally attached piezoelectric sensor, the accelerometer sensor showed lower rate changes during external tapping of the pacemaker (16 +/- 3 vs 29 +/- 4 ppm, P less than 0.02) and applied direct pressure (1 +/- 1 vs 40 +/- 3 beats/min, P less than 0.001) on the pacemaker. At nominal setting, the accelerometer sensor showed improved rate stability and higher rate response to jogging and standing, although responses to other daily activities and treadmill exercise were similar. Apart from changing the rate responsive slope, rate response could be improved by repeat "tailoring" of the sensor at a lower exercise level, resulting in better overall rate response characteristics. The ability of the rate monitoring software to collect acceleration levels for an activity and profile the projected rate response at different rate responsive settings allowed programming to be effected with the minimum amount of exercise testing. The pacemaker also discriminated atrial tachyarrhythmias from normal sinus response using the sensor to judge the appropriateness of the atrial rate, which correctly identified and prevented rapid ventricular tracking in two patients during atrial flutter/fibrillation.
对11例心动过缓患者（7例房室传导阻滞，4例病态窦房结综合征）评估了基于加速度计的DDDR起搏器的频率适应性特征和起搏器介导的心动过速保护算法。通过在3分钟适度运动期间收集加速度水平来实现频率适应性编程（传感器“定制”）。与外部连接的压电传感器相比，加速度计传感器在起搏器外部轻敲时频率变化较小（16±3对29±4 ppm，P<0.02），对起搏器施加直接压力时频率变化也较小（1±1对40±3次/分钟，P<0.001）。在标称设置下，加速度计传感器显示出更好的频率稳定性，对慢跑和站立的频率反应更高，尽管对其他日常活动和跑步机运动的反应相似。除了改变频率响应斜率外，通过在较低运动水平重复“定制”传感器可改善频率反应，从而产生更好的总体频率反应特征。频率监测软件能够收集活动的加速度水平并描绘不同频率响应设置下的预计频率反应，从而允许在最少运动测试的情况下进行编程。该起搏器还利用传感器判断心房率的适当性，将房性快速性心律失常与正常窦性反应区分开来，在两名患者发生心房扑动/颤动期间正确识别并防止了快速心室跟踪。
