Gunderson Bruce D, Gillberg Jeffrey M, Wood Mark A, Vijayaraman Pugazhendhi, Shepard Richard K, Ellenbogen Kenneth A
Medtronic, Inc., Minneapolis, Minnesota, USA.
Heart Rhythm. 2006 Feb;3(2):155-62. doi: 10.1016/j.hrthm.2005.11.009.
Implantable cardioverter-defibrillator (ICD) lead failures often present as inappropriate shock therapy. An algorithm that can reliably discriminate between ventricular tachyarrhythmias and noise due to lead failure may prevent patient discomfort and anxiety and avoid device-induced proarrhythmia by preventing inappropriate ICD shocks.
The goal of this analysis was to test an ICD tachycardia detection algorithm that differentiates noise due to lead failure from ventricular tachyarrhythmias.
We tested an algorithm that uses a measure of the ventricular intracardiac electrogram baseline to discriminate the sinus rhythm isoelectric line from the right ventricular coil-can (i.e., far-field) electrogram during oversensing of noise caused by a lead failure. The baseline measure was defined as the product of the sum (mV) and standard deviation (mV) of the voltage samples for a 188-ms window centered on each sensed electrogram. If the minimum baseline measure of the last 12 beats was <0.35 mV-mV, then the detected rhythm was considered noise due to a lead failure. The first ICD-detected episode of lead failure and inappropriate detection from 24 ICD patients with a pace/sense lead failure and all ventricular arrhythmias from 56 ICD patients without a lead failure were selected. The stored data were analyzed to determine the sensitivity and specificity of the algorithm to detect lead failures.
The minimum baseline measure for the 24 lead failure episodes (0.28 +/- 0.34 mV-mV) was smaller than the 135 ventricular tachycardia (40.8 +/- 43.0 mV-mV, P <.0001) and 55 ventricular fibrillation episodes (19.1 +/- 22.8 mV-mV, P <.05). A minimum baseline <0.35 mV-mV threshold had a sensitivity of 83% (20/24) with a 100% (190/190) specificity.
A baseline measure of the far-field electrogram had a high sensitivity and specificity to detect lead failure noise compared with ventricular tachycardia or fibrillation.
植入式心脏复律除颤器（ICD）导线故障常表现为不适当的电击治疗。一种能够可靠地区分室性快速心律失常和导线故障所致噪声的算法，可预防患者不适和焦虑，并通过防止不适当的ICD电击来避免装置诱发的心律失常。
本分析的目的是测试一种ICD心动过速检测算法，该算法可区分导线故障所致噪声与室性快速心律失常。
我们测试了一种算法，该算法在感知到导线故障引起的噪声时，使用心室心内电图基线的测量值来区分窦性心律等电位线与右心室线圈-罐（即远场）电图。基线测量值定义为以每个感知到的电图为中心的188毫秒窗口内电压样本的总和（mV）与标准差（mV）的乘积。如果最后12次心跳的最小基线测量值<0.35 mV-mV，则检测到的节律被认为是导线故障所致噪声。选取24例有起搏/感知导线故障的ICD患者中首次被ICD检测到的导线故障和不适当检测情况，以及56例无导线故障的ICD患者的所有室性心律失常情况。对存储的数据进行分析，以确定该算法检测导线故障的敏感性和特异性。
24次导线故障事件的最小基线测量值（0.28±0.34 mV-mV）小于135次室性心动过速事件（40.8±43.0 mV-mV，P<.0001）和55次心室颤动事件（19.1±22.8 mV-mV，P<.05）。最小基线<0.35 mV-mV阈值的敏感性为83%（20/24），特异性为100%（190/190）。
与室性心动过速或心室颤动相比，远场电图的基线测量值对检测导线故障噪声具有较高的敏感性和特异性。
