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。     

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。     

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。     

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。     

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。     

自动化起搏器在病窦综合征中的应用分析

目的通过对病窦综合征患者植入自动化起搏器的随访,分析其心房自动阈值管理、心室自动阈值管理、自动房室间期搜索等功能的安全性和有效性。方法选取病窦综合征26例,其中植入Enpluse E2D01起搏器13例、Adapta ADDR01起搏器6例、Kappa 701起搏器7例;植入时Adapta ADDR01起搏器关闭最小心室起搏功能;分别于起搏器植入后1,3,6个月时复查起搏器参数。结果随访的Enpluse、Adapta起搏器病例均完成了心房起搏阈值自动管理;于1,3,6个月随访时,手动与自动测量的心房阈值无差异。所有随访的病例均完成心室起搏阈值自动管理;于1,3,6个月随访时,手动与自动测量心室阈值无差异。术后随访患者大部分心室事件为感知事件。结论 Enpluse、Adapta、Kappa起搏器的自动化功能安全、有效。     

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.     

自动阈值夺获型起搏器心室除极波值与QRS波振幅的相关性研究

目的探讨具有自动阈值夺获功能的起搏器患者起搏的心室除极波值(evoked response,ER)与自主QRS波振幅及有关因素的相关性。方法对161例置入ST.JUDE公司生产的、具有自动阈值夺获功能起搏器患者术中分别测定的自主QRS波R波振幅值、阻抗、起搏阈值及起搏ER值并对ER值的有关因素进行相关分析。结果R波振幅值13.08±4.82mV,ER值99%可信区间11.90~15.01mV,二者相关系数r值为0.05(P>0.05)。结论置入自动阈值夺获功能起搏器时,自主QRS波振幅的高度与ER值之间无相关性,术中应单独进行ER值的测试,以策安全。     

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。     

起搏器心室阈值自动管理功能相关的心电学特点

起搏器阈值自动管理使起搏心电图的表现越来越复杂化,心房通道的起搏、感知功能障碍会影响心室通道的起搏、感知功能,导致假性心室起搏、感知功能不良。由于心室刺激除极(ER)波检测窗存在初始空白期,自身QRS波落入ER波检测窗感知空白期内时不会被起搏器感知,可以引起与ER波感知空白期相关的特殊心电学特点。     

Automatic measurement of atrial pacing thresholds in dual-chamber pacemakers: Clinical experience with atrial capture management

BACKGROUND: The Medtronic EnPulse pacemaker incorporates the new atrial capture management (ACM) algorithm to automatically measure atrial capture thresholds and subsequently manage atrial pacing outputs. OBJECTIVES: The purpose of this study was to evaluate the clinical performance of ACM. METHODS: Two hundred patients with an indication for a dual-chamber pacemaker underwent implantation. ACM thresholds and manually measured atrial pacing thresholds were assessed at follow-up visits. Clinical equivalence was defined as the ACM-measured threshold being within -0.25 V to +0.5 V of the manually measured threshold. The clinician analyzed all ACM measurements performed in-office for evidence of proarrhythmia. RESULTS: All 200 implanted patients had a 1-month visit, and validated manual and in-office ACM threshold data were available for 123 patients. The ACM threshold was 0.595 +/- 0.252 V, and the manual threshold was 0.584 +/- 0.233 V. The mean difference was 0.010 V with a 95% confidence interval of (-0.001, 0.021). The mean difference over all visits was 0.011 V. For all patients, the individual threshold differences were within the range of clinical equivalence at all visits. No atrial arrhythmias were observed during 892 ACM tests in 193 patients. CONCLUSION: This study demonstrated that the ACM algorithm is safe, accurate, and reliable over time. ACM was demonstrated to be clinically equivalent to the manual atrial threshold test in all patients at 1 month and over the entire follow-up period of up to 6 months. ACM ensures atrial capture, may save time during follow-up, and can be used to manage atrial pacing outputs.     

起搏器植入晚期可逆性阈值升高原因分析及对策

目的 分析起搏器植入患者中,出现晚期可逆性阈值升高的原因,探求解决方法。方法 回顾性分析在2003 -2012年本院植入起搏器的1 143例患者,对出现晚期可逆性阈值升高的7例患者的疾病特点进行总结 。结果 7例患者中,4例出现黑矇或短暂意识丧失,心电图存在失夺获表现;1例心房起搏失夺获,但心室起搏功能良好,无临床症状;2例因安装有具有阈值自动管理功能起搏器,无临床症状。7例的心房基线阈值为0.5 - 0.75 V,心室基线阈值为0. 5 -0.75 V,并发急性病情时,6例心室阈值均超过2.5 V,1例心房阈值超过2.5V。7例患者都有不同的急症,包括大面积烧伤、慢性肾功能不全急性加重、心功能衰竭并呼吸衰竭,导致了酸中毒、高钾血症、心肌缺血缺氧。在急症缓解后,7例心房、心室阈值出现下降,心房阈值降为0. 5 -1. 0 V,心室阈值降为0. 5 - 1. 5 V,起搏器在原有参数设置下工作恢复了正常。 结论 心功能不全、呼吸衰竭、肾功能不全等疾病可引起心肌外环境异常,导致晚期起搏阈值突然升高,具有阈值自动管理功能的起搏器可适时调节起搏阈值。     

Threshold Tracking Pacing Based on Beat by Beat Evoked Response Detection: Clinical Benefits and Potential Problems

Continuous monitoring of pacemaker stimulation thresholds and automatic adjustment of pacemaker outputs were among the longstanding goals of the pacing community. The first clinically successful implementation of threshold tracking pacing was the Autocapture feature which has accomplished automatic ventricular capture verification for every single stimulus by monitoring the Evoked Response (ER) signal resulting from myocardial depolarization. The Autocapture feature not only decreases energy consumption by keeping the stimulation output slightly above the actual threshold, but also increases patient safety by access to high-output back-up pulses if there is loss of capture. Furthermore, it provides valuable documentation of stimulation thresholds over time and serves as a valuable research tool. Current limitations for its widespread use include the requirements for implantation of bipolar low polarization leads and unipolar pacing in the ventricle. Fusion/pseudofusion beats with resultant insufficient or even non-existent ER signal amplitudes followed by unnecessary delivery of back-up pulses and a possible increase in pacemaker output is not an uncommon observation unique to the Autocapture feature. The recent incorporation of the Autocapture algorithm in dual chamber pacemakers has been challenging because of more frequent occurrence of fusion/pseudofusion beats in the presence of normal AV conduction. Along with a review of the previously published studies and our clinical experience, this article discusses the clinical advantages and potential problems of Autocapture.     

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.     

Atrial pacing and sensing characteristics in heart failure patients undergoing cardiac resynchronization therapy.

Patients with heart failure and sinus rhythm undergoing cardiac resynchronization therapy (CRT) require the proper detection of atrial signals and reliable atrial pacing for AV-synchronous ventricular pacing. The study aim was to compare atrial pacing and sensing characteristics in patients with transvenous CRT and patients with standard pacing indications. METHODS: The study group consisted of 31 heart failure patients with depressed left ventricular function and bundle branch block, and the control group of 124 patients with dual-chamber pacemakers because of standard pacing indications. The bipolar steroid-eluting atrial screw-in lead Tendril DX 1388 T (St. Jude Medical) was implanted and connected to pulse generators that provide similar diagnostic features. The unipolar pacing threshold at 0.4 ms duration, bipolar sensing threshold, and unipolar pacing impedance were determined at implantation and after 1, 3, and 6 months. RESULTS: At implantation, the atrial pacing threshold was significantly higher in the CRT group than in the control group, 1.07+/-0.99 V versus 0.74+/-0.36 V (P<0.01). Similar pacing thresholds were recorded after 1 month. The pacing threshold in the CRT group was significantly higher at 1.46+/-0.92 V after 3 and 1.50+/-0.94 V after 6 months (control group: 0.96+/-0.25 V at month 3; 0.98+/-0.32 V at month 6; P<0.05). Sensing threshold was similar at implantation with 2.36+/-1.87 mV in the CRT and 2.54+/-0.78 mV in the control group. The sensing threshold in the CRT group decreased to 1.64+/-0.8 6mV after 3 and to 1.71+/-0.71 mV after 6 months and was significantly lower compared with the control group (2.16+/-0.57 mV at month 3; 2.27+/-0.9 8mV at month 6; P<0.05). At implant, the atrial pacing impedance was not different between the two groups with 443+/-156 ohms in the CRT and 416+/-116 ohms in the control group. During follow-up, the impedance became significantly lower in the CRT group compared with the control group (404+/-84 ohms versus 452+/-101 ohms at month 3; P<0.05). CONCLUSIONS: Compared with patients with standard pacing indications, CRT recipients have less good electrical characteristics in the atrium. Atrial pacing and sensing function should be closely monitored in CRT patients.