Small bowel capsule endoscopy in patients with cardiac pacemakers and implantable cardioverter defibrillators:Outcome analysis using telemetry review

AIM:To determine if there were any interactions between cardiac devices and small bowel capsules secondary to electromagnetic interference (EMI) in patients who have undergone small bowel capsule endoscopy (SBCE).METHODS:Authors conducted a chart review of 20 patients with a cardiac pacemaker (CP) or implantable cardioverter defibrillator (ICD) who underwent continuous electrocardiographic monitoring during their SBCE from 2003-2008.authors searched for unexplained electrocardiogram (ECG) findings,changes in CP andICD set parameters,any abnormality in transmitted capsule data,and adverse clinical events.RESULTS:There were no adverse events or hemodynamically significant arrhythmias reported.CP and ICD set parameters were preserved.The majority of ECG abnormalities were also found in pre-or post-SBCE ECG tracings and the CP behavior during arrhythmias appeared appropriate.Two patients seemed to have episodes of undersensing by the CP.However,similar findings were documented in ECGs taken outside the time frame of the SBCE.One patient was observed to have a low signal encountered from the capsule resulting in lack of localization,but no images were lost.CONCLUSION:Capsule-induced EMI remains a possibility but is unlikely to be clinically important.CPinduced interference of SBCE is also possible,but is infrequent and does not result in loss of images transmitted by the capsule.

Therapeutic effect of a dualchamber pacemaker with the optimized program-control mode on long-qt syndrome

Objectives To explore the optimized program-control mode of a dual-chamber pacemaker combined withβ-blocker to treat congenital long QT syndrome(LQTS). Methods 12 LQTS patients in our hospital that still have symptoms despite use of regular drug therapies or that can not endure the therapies were implanted with DDD cardiac pacemaker.The QT/QTc intervals of those patients were measured at different pacing rates respectively.Their cardiac pacemakers were all programmed to selectively turn on and turn off some related functions at the pacing rate of 80 beats/min.The dosage ofβ-blockers was adjusted according to the patients’ PR intervals and blood pressures.The MACE and the cardiac function of the patients were recorded after operation.Results The measured QT / QTc interval decreased with the pacing rate increasing.The pacing rate of 80 beats/min can make QT/QTc interval basically normal. The MACE of the patients were statistically declined(P = 0.003) and no negative effect on cardiac function was found during the follow-up.Conclusions The optimized program-control mode of a dual-chamber pacemaker combined withβ-blocker to treat congenital LQTS are:to pace at the rate of 80 beats/min and program to turn off lag,sleep,automatic preventing PMT and automatic threshold-capture feature and turn on the PVC,rate adaptation and atrioventricular node priority function.

Interference between pacemakers/implantable cardioverter defibrillators and video capsule endoscopy

Our Letter to the Editor, related to the article "Small bowel capsule endoscopy in patients with cardiac pacemakers and implantable cardioverter defibrillators: Outcome analysis using telemetry" by Cuschieri et al , comments on some small errors, that slipped into the authors discussions. The given informations concerning the pacemakerand implantable cardioverter defibrillators modes were inaccurate and differ between the text and the table. Moreover, as 8 of 20 patient's pacemakers were programmed to VOO or DOO ("interference mode") and one patient was not monitored by telemetry during capsule endoscopy, 9 of 20 patients (45%) lack the informations of possible interference between capsule endoscopy their implanted device. Another objection refers to the interpretation of an electrocardiogram (figure 1, trace B) presented: in contrast to the author's opinion the marked spike should be interpreted as an artefact and not as "undersensing of a fibrillatory wave". Finally, three comments to cited reviews were not complete respectively not quoted correctly.

微处理器控制的植入式心脏起搏器专用电路研制

介绍了一种基于微处理器的植入式心脏起搏器专用电路设计。该设计采用的技术路线和国外现有技术方案不同,它采用通用微处理器设计,降低了投资风险,缩短了开发周期,特别适合于我国这样的发展中国家。

用于心脏起搏器的程控遥测新技术

讨论一新型的起搏器程控遥测技术。该技术采用数字逻辑电路设计,程控部分采用单片机控制,并同PC机连接,可方便地调试和显示。提出的脉宽调制、反射遥测,可提高信号传输的正确率和纠错能力,降低起搏器功耗,延长其使用寿命。

基于LPC2103的植入式心脏起搏器程控仪设计

本文介绍了一种植入式心脏起搏器程控仪的工作原理与系统构成,该程控仪以LPC2103为核心搭建系统电路,并进行系统软件的编写,通过无线耦合的数据传输方式,实现程控仪对植入式心脏起搏器的程控与遥测。

遥测技术对预测和延长起搏器寿命的临床意义

目的:为选择长期有效和适宜的低起搏器输出。方法:23例心动过缓患者植入起搏器Minix 2台,Prevail 2台及 Premier19台,激素电极4023型4条和4003型19条。用9710 E 程控器(Medtronic)以手控测阈值法和遥测技术(RTT)随访慢性起搏阈值,平均电池耗电(μA)和脉冲能量输出(μJ)等参数3～27个月以上。结果:1.6 V 和0.8 V 的慢性起搏脉宽阈值分别为0.11±0.04(0.06～0.18)ms 和0.20±0.08(0.12～0.42)ms,并发现1.6 V 和2倍于其脉宽阈值起搏的电池耗电量(5.45±0.59μA)比0.8 V和3倍于其脉宽阈值起搏的5.96±0.88μA更低(P<0.05)而1.6 V 起搏的脉冲能量输出(1.74±0.53μJ)则比0.8 V 起搏(0.92±0.40μJ)更大(P<0.001)。设置1.6 V 和其脉宽阈值的2倍(脉宽阈值0.06 ms 时置于0.18 ms)的平均安全范围(能量输出/能量阈值)为5.6倍,随访16～40个月证明起搏良好,预期平均寿命为21.2±2.13年,均明显优于设置输出为0.8 V 和3倍于其脉宽阈值的工作寿命(19.5±2.65年)及其安全范围(3倍)。结论:本结果提示起搏器输出1.6 V 比0.8V 的预期起搏器寿命更长(21.2比19.5年),且其平均安全范围更大(5.6比3.0)。