连续夺获阈值监测与自动调节起搏器刺激输出——MICRONY SR+起搏器多中心研究

Automatic adjustment of pacemaker stimulation output correlated to continuously monitored capture thresholds.A muiticenter study of the MICRONY pulse generator

目的:本研究评价具有心室自动夺获功能的 Microny 起搏器的安全性及功效。方法:自1994年11月至1996年9月欧洲国家的16个医学中心,共有113例植入 Microny 起搏器的患者进入了研究。所有植入的起搏器采用了 Pacesetter 的低极化、双极电极导线(Membrane 1402 T)。患者在出院时及出院后1、3、6、12个月分别进行随访。结果:在植入后1个月的随访中,动态心电图显示所有未夺获的心搏均有后备起搏脉冲(4.5 V/0.49 ms)出现。植入时测试自身 R 波高度为14.7±7.4 mV,刺激除极波高度(ER)为10.2±4.8 mV。这些数值随时间推移保持稳定,但二者无相关性(r=0.29),植入时,由VARIO 功能测试的起搏阈值为0.5±0.2 V,由自动夺获功能测试的阈值为0.6±0.3 V。两种方法测试的起搏阈值在各次随访中相关性较好(r=0.79),平均差异为0.11 V。后备起搏脉冲占起搏刺激的1.1%。发放后备起搏脉冲的原因为未能夺获(7.1%);(伪)融合波(87.0%);ER 感知低下(0.5%)和QRS 感知低下(4.1%)。在自动夺获功能打开时,起搏电流总消耗为1.4 A。结论:本研究证明了自动夺获功能根据当时的起搏阈值安全和可靠地调节起搏器的输出,为患者提供最大的安全性并延长起搏器的使用寿命。

Objective:Pacing threshold is affected by many factors.A pacing system able to confirm capture at each beat and automatically adjust its output to just ahove the actual pacing threshold is highly desirable.This study is to evaluate the safety and efficacy of the Pacesetter Microny pulse generator fea- tured with autocapture in ventricle.Methods:In 16 centers in 7 European countries,113 patients were enrolled and received Microny pulse generator between November 1994 and September 1996.All pacemak- ers were implanted with Pacesetter's low polarization,bipolar leads(Membrane 1,402 T).Patients were fol- lowed up at discharge,1,3,6,12 months post implant.A Holter recording at one month follow-up showed that all losses of capture were followed by backup pulses(4.5 V/0.49 ms)Results:The spontaneous R amplitude(mean±s)was 14.7±7.4 mV and evoked response(ER)10.2±4.8 mV at the implantation. They were stable over time and not correlated to each other(r=0.29).The pacing threshold at implanta- tion was 0.5±0.2 V mesasured by VARIO and 0.6±0.3 V by Autocapture.Thresholds from both me thods were correlated at all follow-ups(r=0.79)with a mean difference of 0.11 V.The median backup pulses was 1.1% per paced stimuli.The causes of the backup pulses were identified to be 7.1% loss of cap- ture,87.0%(pseudo)fusion beats,0.5% ER undersensing and 4.1% QRS undersensing.The overall pac- ing current consumption was 1.4 μA with Autocapture ON.Conclusion:This study proved that the Autocapture safely and reliably regulates the pacemaker's output according to the prevailing threshold.This provides maximum patient safety and leads to prolonged service life.