EnPulse起搏器自动化功能的临床研究

目的:通过对EnPulse起搏器安置患者的随访,了解心房及心室自动阈值管理、自动AV间期搜索等功能的安全性和有效性.方法:选取置入Enpluse E2D01起搏器患者15例,分别于起搏器置入后1个月及6个月时复查起搏器参数,包括起搏器最近1次自动测量的心房及心室起搏阈值,手动测量心房及心室起搏阈值,记录患者心室感知占心室总事件的比例,并记录由Search AV+所设定AV间期基础上的心室感知事件所占心室总事件的比例.结果:1个月及6个月随访时,手动测量心房及心室阈值与自动测量心房及心室阈值差异无统计学意义.术后病态窦房结综合征患者大部分心室事件为感知事件,其中绝大多数由search AV+功能参与.结论:EnPulse起搏器的自动AV搜索功能、心房及心室自动阈值管理是安全有效的.     

Zephyr DR型起搏器自动夺获功能的临床随访

目的:通过对植入Zephyr DR型起搏器患者的随访,了解心房及心室自动阈值管理的安全性和有效性。方法:对植入Zephyr DR型起搏器7例患者,分别于起搏器植入后1、3、6个月复查起搏参数,包括自动测量心房、心室起搏阈值,手动测量心房、心室起搏阈值。结果:1、3、6个月随访时心房、心室自动测试和手动测试测得的阈值差异无统计学意义(P>0.05)。结论:Zephyr DR型起搏器自动阈值夺获功能耗能低而且安全有效。     

具有心房自动阈值管理功能起搏器在病窦综合征患者中的临床应用

目的观察具有心房自动阈值管理功能起搏器在病窦综合征患者中的临床应用情况。方法18例病窦综合征患者置人具有心房自动阈值管理功能起搏器（Enpulse系列7例,Sensial系列5例,Adapta系列6例）,于置入时,置入后1周、1个月、6个月采用起搏分析仪及体外起搏器程控仪测定心房起搏阈值和阻抗,利用ACM进行术后阈值和阻抗的动态观察。结果测定的心房阈值与ACM测定值差异无统计学意义;心房起搏阈值均〈1．0V,心房起搏阈值于置入1个月后有下降趋势,阻抗未见明显变化。预期使用寿命6个月时测定为（8．7±2．4）年。结论病窦综合征患者置入具有心房自动阈值管理功能的起搏器心房起搏安全有效,起搏器预期使用寿命延长。     

具有自动阈值管理和房室搜索功能起搏器Enpulse的临床应用

目的动态观察具有自动阈值管理和房室搜索功能起搏器Enpulse的临床应用。方法76例患者植入了Enpulse系列起搏器,于植入时,植入后1,6个月采用手工测试心房、心室起搏阈值和阻抗并与心房、心室自动阈值管理(ACM、VCM)测定的值进行比较,并利用ACM、VCM进行术后阈值和阻抗的动态观察。计算术后心室起搏百分比,并与传统起搏器相比较。结果72例完成随访。手工测试的心房、心室阈值与ACM、VCM测定的无显著性差异。心房、心室起搏阈值均小于1 V,心房起搏阈值于植入1个月后有下降趋势,而阻抗未见有明显变化;心室起搏阈值无明显变化,但阻抗于植入2～6个月时有下降趋势。Enpulse起搏器的心室起搏比例为4.895%±9.0589%,明显小于传统起搏器(79.479%±16.159 3%,n=60)。结论Enpulse的自动阈值管理能自动测定阈值,并以较小的能量输出安全起搏,AV搜寻功能明显减少心室起搏比例。     

新型心房自动阈值管理功能ACap~(TM)confirm的临床探索

目的:观察起搏器新型心房自动阈值管理功能ACapTMconfirm的开启情况,通过比较该功能打开后的心房手动及自动测试阈值,评价该功能的准确性、安全性和临床等效性。方法:选取33例置入Zephyr5826型双腔起搏器且资料完整的患者,至观察期植入时间平均20.5个月。记录打开ACapTMconfirm功能的患者数,并收集ACapTMconfirm功能打开后的自动及手动阈值。通过比较自动、手动测量心房起搏阈值,评估心房自动阈值管理功能ACapTMconfirm的临床等效性。结果:33例患者中有14例打开了ACapTMconfirm功能,19例未打开。未打开ACapTMconfirm的原因包括基础心率过快(1例,5.3%)及心房刺激除极波感知不足(18例,94.7%)。随访过程中总共获得22组自动、手动心房阈值,其中自动阈值平均0.375~1.375V,平均(0.528±0.270)V;手动阈值平均0.500~1.250V,平均(0.580±0.223)V;自动、手动阈值之间差异有统计学意义(P0.05);打开ACapTMconfirm后1、2、4个月测得的自动、手动阈值均比较差异均无统计学意义(P0.05)。随访的33例患者中,ACapTMconfirm的总打开率为42.4%。结论:心房自动阈值管理功能ACapTMconfirm通过准确判断心房起搏阈值,调整心房输出,可起到减少起搏器耗电,延长起搏器使用时间的作用,具有临床使用的安全性和有效性。     

Adapta起搏器防治心房颤动的临床研究

心房颤动(房颤)是临床上最常见的心律失常之一。植入有心室起搏管理(MVP)功能的Adapta起搏器的病态窦房结综合征患者能够最大程度鼓励自身传导,减少右室心脏起搏,降低持续性房颤的发生风险[1]。目前带有MVP功能的起搏器在国内应用尚不多,本文评价Adapta起搏器生理性起搏的安全性和有效性。     

起搏器心房自动阈值管理功能的临床研究

目的:通过对植入起搏器患者的随访,了解心房自动阈值管理功能的可靠性和安全性。方法:选择植入Medtronic Enpulse双腔起搏器的患者43例,于植入起搏器后的1、3、6个月分别程控随访,用人工测定法和自动测定法测定起搏器的心房输出阈值、感知和导线阻抗。结果:植入起搏器1、3、6个月后,随访时人工测定和自动测定的心房输出阈值分别为(0.60±0.26)V与(0.60±0.23)V、(0.55±0.19)V与(0.56±0.18)V、(0.58±0.20)V与(0.59±0.21)V,差异无统计学意义;且心房感知度和导线阻抗的人工测定与自动测定间无差异。在心房自动起搏阈值测定过程中未诱发任何心律失常。结论:起搏器的心房自动阈值管理功能的临床应用是可靠和安全的。     

心房起搏自动阈值管理功能的临床应用

起搏器起搏阈值是指起搏器起搏心脏需要的最小电能,即起搏器的最低输出.其大小受生理、病理、药物等诸多因素影响常处于波动状态,会增加起搏器能量消耗,减少起搏器使用寿命,可能造成起搏器阈值升高时的失夺获[1].1972年,Funke首先提出通过起搏器自动检测心脏起搏阈值,并以高于起搏阈值较少的能量起搏心脏,可增加起搏器应用安全性,延长起搏器电池寿命.大量研究证实,心室起搏阈值的自动测定和自动调整功能成为评价心室起搏功能的金标准[2-4].与心室除极波相比,心房除极波很小,很难通过测量心房电脉冲刺激后心房除极波判断刺激脉冲是否真正夺获心房,因此,心房自动阈值管理一直是临床一大难题.本文就起搏器心房阈值管理功能的相关研究及临床应用作一综述.     

以起搏除极积分刺激除极波检测法确认夺获与否的心室自动阈值管理的临床观察

目的:通过对植入Zephyr5826起搏器患者的随访,观察以起搏除极积分刺激除极波检测法(PDI)测算刺激除极波下面积方式确认夺获与否的心室自动阈值管理(VCM)的临床观察。方法:选取植入Zephyr5826起搏器患者102例,术后即刻将心室电极设置为双极感知、双极起搏以满足PDI测算刺激除极波下面积的设置需要,观察患者术后第1 d、7 d及1、3、6、12个月时VCM功能的开启情况及工作情况,并将VCM阈值与手动测定阈值进行比较。观察随访患者有无胸大肌刺激、膈肌刺激及心悸感。结果:1例术后1个月时因急性心肌梗死去世,余101例均随访12个月。随访期内102例均于术后即刻成功开启VCM功能。101例患者随访期内均无胸大肌刺激、膈肌刺激等症状出现,6例(5.9%)因不能耐受每日阈值自动测试过程引起的心悸感于术后7 d时关闭VCM功能,之后随访时临时测试并记录VCM阈值。VCM阈值与手动测定阈值临床符合率100%(临床符合定义为VCM阈值与手动测定阈值相差-0.125~+0.125 V)。VCM功能对其中1例患者术后第1d时阈值升高至2.125 V的情况亦能准确识别并自动调整输出为2.375 V。VCM功能开启时的心室起搏输出电压为(0.99±0.48)V(n=608),依焦耳定律算得,与普通电压起搏(2.5 V,0.4 ms)相比,VCM功能在心室起搏输出方面可节省84%的能量消耗,与高电压起搏(3.5 V,0.4 ms)相比,可节省92%的心室起搏能量消耗。随访期间心电图及24小时动态心电图均未见心室失夺获及感知不良。结论:Zephyr5826双腔起搏器通过新测算方法实现双极起搏模式下的VCM功能,可以安全有效的应用低能量起搏心脏,少数患者因无法耐受自动测试过程中的心悸感无法开启VCM功能。     

具有自动夺获功能心室起搏器的临床观察

我科1998年1月至10月共植入具有自动夺获功能心室起搏器6例,男4例、女2例,年龄64.3±10.5岁。植入起搏器的适应证为病窦综合征2例、度房室阻滞2例、度型房室阻滞2例。其中合并阵发性心房扑动1例、合并阵发性心房颤动2例。植入起搏器均为Pacesetter公司的RegencySC (VVI型),电极亦为该公司提供的带有激素释放功能的低极化1470T双极电极。起搏器植入手术与普通VVI起搏器相同。术中除常规测定起搏阈值、阻抗、R波振幅外,尚需加测刺激除极波(ER)的振幅。术后当天,用APSu3250型程控仪将起搏器自动夺获功能打开。术后1周及1,3,6,9个月进行…     

Realisierbarkeit und Sicherheit einer alleinigen AAI(R)-Schrittmacherbehandlung beim isolierten symptomatischen Sinusknotensyndrom

Recent investigations prove that AAI(R) pacing is the "ideal" stimulation mode in isolated sick sinus syndrome. Nevertheless, in Germany this bradycardia is treated by AAI(R) pacemakers in less than 4% of cases compared to 25% in other countries. In our institution treatment of patients with isolated sick sinus syndrome is uniform and corresponds to the actual guidelines since the early 1990s; therefore the aim of our study was to analyze feasibility and safety of AAI(R) pacing in a retrospective study.Between 1998 and 2000, 52 of 165 patients (31.5%) with isolated sick sinus syndrome were treated by an AAI(R) pacemaker. The median follow-up duration was 51.5 months (minimal: 36 months). 6 patients died, in all cases unrelated to the stimulation mode. Three patients required reoperations, however, in only one case due to second degree AV block with the need for upgrading to DDD stimulation. Thus, the yearly incidence of this specific complication in the AAI(R) cohort is 0.64%.In conclusion, permanent atrial stimulation in isolated sick sinus syndrome is feasible in a quarter of all cases. It is safe if performed corresponding to actual guidelines. Additionally, single lead AAI(R) pacing is a cost-effective therapy and the only stimulation mode which, today, reliably prevents unnecessary right ventricular stimulation. If, on the other hand, algorithms providing automatic mode switching from AAI to DDD and vice versa are implemented reliably into all dual chamber pacemakers, single chamber atrial pacing will no longer be a subject for discussion.     

Uni- and bipolar pacing threshold measurements with capturecontrol, a new automatic pacemaker function for capture verification. Comparison of the automatic and the manual pacing threshold measurement

It is mandatory in pacemaker patients to determine the pacing threshold at each follow-up visit. To facilitate the pacing threshold measurements, complete automatic pacemaker tests are being developed. A new pacemaker algorithm for automatic capture verification (Capturecontrol) detects the presence of the evoked response signal 70-100 ms after the pacing pulse. The aim of this study was to determine the uni- and bipolar pacing thresholds using this automatic pacemaker function and compare them with the manually determined threshold. The study included 14 patients with the DDD pacemaker Logos (Biotronik) connected to the high-ohmic ventricular pacing lead Synox SX 60-BP (Biotronik). At predischarge and 8, 14, 20 and 26 weeks after implantation the uni- and bipolar pacing thresholds were assessed manually and with the automatic pacemaker function at 0.4 ms duration. Mean pacing thresholds determined with the automatic pacemaker function were not different from the manually measured values. This applied to uni- and bipolar pacing. Seventy percent of all unipolar and 67% of all bipolar measurements had no deviation. A deviation of 0.1 V between manual and automatic threshold measurement was observed in 25% (unipolar) and 28% (bipolar), respectively. A 0.2-volt difference occurred in 3% in the unipolar measurements. Deviations >/=0.3 V were found in 2% of all unipolar and in 5% of all bipolar measurements. In conclusion, automatic pacing threshold measurements using the Capturecontrol algorithm were similar compared to the manually determined thresholds. The excellent agreement between the two methods was observed for bipolar as well as unipolar pacing and on condition that all patients had a high-ohmic ventricular pacing lead. Therefore, fewer requirements are necessary for Capturecontrol than for presently available systems. Such pacemaker functions can help to speed up the measurements during follow-up visits.     

Adverse effects of direct current cardioversion on cardiac pacemakers and electrodes Is external cardioversion contraindicated in patients with permanent pacing systems?

Use of pacing in sick sinus syndrome and recent developments in pacemaker therapy for intermittent atrial fibrillation raise the question of whether external electrical cardioversion should be used for termination of atrial fibrillation. This paper analyzes three cases of pacemaker and/or electrode dysfunction appearing after direct current (DC) cardioversion for termination of atrial fibrillation. Despite similar conditions during cardioversion in all cases, different dysfunctions reflecting damage to the pulse generator and/or a rise of the stimulation threshold in both, atrial and ventricular leads, have been observed. The possible mechanisms for these effects are discussed and recommendations for the management of cardioversion in patients with permanent pacemaker systems are given.     

Blind atrial pacing for patients with sinus node disease who develop atrial fibrillation during permanent pacemaker implantation

During a 6-year period, six of 110 patients implanted with AAI pacemakers for sick sinus syndrome developed atrial fibrillation at the time of pacemaker implantation (5.5%). In all cases a passive fixation lead was sited in the right atrial appendage, its stability being ensured by rotation of the lead and phrenic nerve stimulation excluded by pacing at 10 V. One patient remained in chronic atrial fibrillation. In the other five, who subsequently reverted to sinus rhythm, atrial P-wave sensing and lead threshold values were satisfactory, allowing programming of the pacemaker output down to 2.5 V to conserve the battery. One out of these five patients continued to have intermittent atrial fibrillation. We conclude that in sick sinus syndrome, atrial fibrillation complicates AAI pacemaker implantation procedure in 5.5% of cases. As an alternative to an unplanned general anaesthetic to cardiovert the patient, it is reasonable to implant an atrial lead in the right atrial appendage in the expectation of a spontaneous reversion to sinus rhythm with a good lead threshold and P-wave sensing. In contrast to inappropriate pacing of the right ventricle in VVI mode, this strategy avoids pacemaker syndrome and reduces the risk of subsequent attacks of atrial fibrillation.     

Our experience using continuous atrial stimulation in sick sinus syndrome

Temporary atrial pacing (AAI) was applied in 31 patients with sick sinus syndrome (S.S.S.), including 20 with tachycardia-bradycardia syndrome (t.b.s.). In all patients before pacemaker implantation atrioventricular conduction was estimated using rapid left atrial, transoseophegeal stimulation assuming Wenckebach's point over 120 imp./min to be a physiological one. In all cases, but one ventricular electrodes were implanted and connected with multiprogrammable pacemakers (MP). Follow-up time ranged from 3 to 38 months (mean 18,4). Electrode dislodgment was not observed. In 9 persons sensing disorders were observed but thanks to programming the pacemaker sensitivity they could be resolved almost in all of them. Second degree Mobitz type I a-v block occurred in 3 patients during a long-term follow-up. In one of them changing the pacing mode to VVI was necessary. In persons with tachycardia-bradycardia syndrome cardiac pacing together with pharmacologic therapy allowed to almost eliminate tachycardia attacks. Authors positively estimated AAI pacing mode.