Haennel R G, Logan T, Dunne C, Burgess J, Busse E
Institute for Health Studies, University of Regina, Saskatchewan, Canada.
Pacing Clin Electrophysiol. 1998 Sep;21(9):1700-8. doi: 10.1111/j.1540-8159.1998.tb00267.x.
The effects of sensor selection and sensor blending on the cardiovascular response to graded exercise was evaluated in 10 patients (age 74 +/- 2 yrs; 7 men and 3 women) implanted with a dual sensor rate adaptive VVIR pacemaker (Vitatron Topaz model 515). Patients underwent three graded exercise tests (GXT) with sensor programming randomly assigned. For a given graded exercise text the pacemaker was programmed into activity sensing (ACT), QT sensing, or dual sensing (ACT = QT). Data were recorded at rest and during each stage of the graded exercise text. Oxygen uptake (VO2) was measured continuously using a Q Plex I system. Heart rate (HR), stroke volume (SV), and cardiac output (Qc) were measured by impedance cardiography. Systolic time intervals were calculated from simultaneous recordings of the ECG, phonocardiogram, and the impedance cardiogram. In response to the GXT no differences in peak VO2 were observed across the three sensor settings. Regardless of the sensor setting Qc increased linearly with each increment in VO2. The HR response to ACT only pacing was significantly higher than in the other two pacing conditions. During ACT only pacing SV failed to rise in response to exercise. The increased exercise Qc during QT and ACT = QT pacing were mediated by significant increases in both HR and SV. The QT and dual pacing conditions were also associated with longer diastolic filling times. The data indicate that the mechanisms responsible for the increase Qc during exercise were different for ACT versus ACT = QT or QT sensor-driven pacing.
在10例植入双传感器频率适应性VVIR起搏器（Vitatron Topaz 515型）的患者（年龄74±2岁；7名男性和3名女性）中，评估了传感器选择和传感器融合对分级运动中心血管反应的影响。患者进行了三次分级运动试验（GXT），传感器编程随机分配。对于给定的分级运动试验，起搏器被编程为活动感知（ACT）、QT感知或双重感知（ACT = QT）。在休息时以及分级运动试验的每个阶段记录数据。使用Q Plex I系统连续测量摄氧量（VO2）。通过阻抗心动图测量心率（HR）、每搏输出量（SV）和心输出量（Qc）。从心电图、心音图和阻抗心动图的同步记录中计算收缩期时间间隔。对GXT的反应中，在三种传感器设置下未观察到峰值VO2有差异。无论传感器设置如何，Qc均随VO2的每次增加而线性增加。仅ACT起搏时的HR反应显著高于其他两种起搏条件。在仅ACT起搏期间，SV未能随着运动而升高。QT和ACT = QT起搏期间运动时Qc的增加是由HR和SV的显著增加介导的。QT和双重起搏条件也与更长的舒张期充盈时间相关。数据表明，运动期间导致Qc增加的机制在ACT与ACT = QT或QT传感器驱动起搏方面有所不同。
