起搏器自动夺获功能失活的观察分析

观察分析自动夺获(AC)功能无法正常工作的原因。41例患者置入具有AC功能的起搏器,术后1周、1个月、3个月随访体表心电图、动态心电图,应用程控仪进行遥测和程控,测定刺激除极波(ER)振幅、极化电位(PS)等参数,观察AC功能的工作情况。结果:41例经术后随访起搏器功能正常。5例(12.2%)在术中虽经多次调整电极位置,也无法术中使用AC功能。4例ER值始终低,极化电位较高(ER/PS<1.5);1例因噪声干扰太大,术中无法测试ER振幅。5例术中未能打开AC功能者,其中4例于1个月后随访时,ER/PS≥2,将AC功能打开。1例术中起搏电极位置在右室基底部者,R波感知>10mV,ER始终小于2.4mV,多次随访均无法安全使用AC功能。术中打开AC功能的36例中,术后随访时5例需关闭AC功能,其原因:①起搏阈值超高≥4.5V(1例),②大量室性融合波导致频繁后备脉冲释放(2例),③后备脉冲(4.5V/0.5ms)工作时的不适感觉(1例,伴室性融合波导致频繁后备脉冲释放),④局部肌肉抽动引起噪声干扰无法进行ER振幅测试(2例)。结论:多种因素都能影响起搏器AC功能。为保障起搏器可靠安全,低耗能状态,近期的随访观察尤为重要。

Analysis of Pacemaker With Inactived Autocapture Pacing System

To investigate the impact of the patients in whom autocapture algorithm could be inactived and evaluate the performance of the autocapture pacing system,forty-one patients who had undergone pacemaker implantation using an autocapture algorithm with leads 1470T were involved in the study.Ventricular stimulation threshold test, sensing of intrinsic R wave, lead impedance,evoked responses (ER) and polarization signals (PS) were measured by a standard pacing system analysis during predischarge and 1 week,1 month,3 month after discharge.The performance of autocapture pacing system was analysed from 24-hour Holter ,ECG ,intracardiac electrogram(IECG) and diagniostic data. Result:The pacing system function was normal in all patients in this study. In 5 patients(12.2%) including 4 patients with inappropriate ER and PS vales,1 patient with noise sampling,autocapture algorithm was inactivated after trying change several lead position in their ventricular at discharge. The system was recommended activating autocapture in 4 of 5 patient from at 1 month. 5 patients from 36 patients whose autocapture algorithm had to turn off autocapture pacing system after discharge follow-up were activated.The main reasons were: ①high pace threshold≥4.5V. ②frenquent fusion beat. ③uncomfortable and mental stress from high voltage backup pulse(4.5V/0.5ms)discharging.④failure in ER test because of noise caused by muscular tremor. Conclusions:Some parameters and facts affect the continuation of autocapture function. It is important for follow-up to enhance safty and low output by autocapture.