Alt E, Kriegler C, Fotuhi P, Willhaus R, Combs W, Heinz M, Hayes D
I. Medical Clinic, Technical University of Munich, Germany.
Pacing Clin Electrophysiol. 1992 Nov;15(11 Pt 2):1873-9. doi: 10.1111/j.1540-8159.1992.tb02985.x.
Energy consumption and longevity of modern pacemakers are determined by the controlling electronic circuitry and by the stimulation energy. While with technological progress the electronics' energy consumption has been reduced significantly, clinical practice shows that many cardiac pacemakers are programmed to suboptimal settings with regard to minimization of pacing energy consumption. Several methods for optimizing pacemaker output settings have been proposed in the past. The most promising concept is an output parameter optimizing pacemaker with automatic capture detection. We examined whether it is possible to distinguish between effective and ineffective pacemaker stimulus capture by analyzing high pass filtered intracardiac impedance signals that are derived from standard bipolar pacing leads. In one series of 11 patients undergoing replacement or implantation of chronic bipolar pacemakers, four patients during electrophysiology studies, and eight volunteers undergoing invasive electrophysiology trials, we examined intracardiac impedance signals obtained with various stimulation rates and output parameter settings. Additionally we analyzed a series of five patients with implanted pacemakers that can measure and telemeter intracardiac impedance signals. Several evaluation concepts have been analyzed regarding their ability to discriminate between effective and ineffective stimuli. We developed an adequate algorithm that detects capture or loss of capture at different output parameter settings based on intracardiac impedance analysis. The sensitivity is 98.5% and specificity is 91% to loss of capture for the currently investigated algorithm and this can be used to determine the optimal setting of pulse width and amplitude with regard to energy consumption. This concept is currently under realization in the external programmer and in the future an implementation of these algorithms within the pacemaker itself is intended.
现代起搏器的能量消耗和使用寿命取决于控制电子电路和刺激能量。随着技术进步，电子设备的能量消耗已大幅降低，但临床实践表明，许多心脏起搏器在起搏能量消耗最小化方面的设置并非最优。过去已提出几种优化起搏器输出设置的方法。最有前景的概念是具有自动捕捉检测功能的输出参数优化起搏器。我们研究了通过分析从标准双极起搏导线获得的高通滤波心内阻抗信号，是否能够区分有效的和无效的起搏器刺激捕捉。在一组11例接受慢性双极起搏器置换或植入的患者、4例在电生理研究期间的患者以及8例接受侵入性电生理试验的志愿者中，我们检查了在各种刺激率和输出参数设置下获得的心内阻抗信号。此外，我们分析了一组5例植入了能够测量和遥测心内阻抗信号的起搏器的患者。已对几种评估概念区分有效和无效刺激的能力进行了分析。我们开发了一种合适的算法，该算法基于心内阻抗分析，在不同输出参数设置下检测捕捉或捕捉丧失。对于目前所研究的算法，捕捉丧失的敏感性为98.5%，特异性为91%，这可用于确定关于能量消耗的脉宽和幅度的最佳设置。这一概念目前正在外部编程器中实现，并且未来打算在起搏器本身内实现这些算法。
