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。     

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。     

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。     

双腔起搏器自动房室间期搜索功能的临床应用观察

目的观察双腔起搏器自动AV间期搜索功能(auto AV search)减少心室起搏的有效性及对心功能和快速房性心律失常的影响。方法43例植入具有自动AV间期搜索功能的双腔DDD(R)起搏器的患者,术后6个月内随机交叉关闭或打开AV search功能各3个月,分别在第一阶段(3个月末)、第二阶段(6个月末)程控获取心室起搏百分比(Vp)、高频心房事件及测试血浆BNP值。结果43例患者按计划完成随访,AV search关闭组心室起搏(VP)比例为78.0±10.3%,心房高频事件为58±15次,血浆脑钠肽(BNP)水平为333±30pg/ml;AVsearch打开组Vp比例为15.9±4.8%,心房高频事件为29±13次,BNP65±21 pg/ml,两者相比具有显著统计学差异(P<0.01)。结论双腔起搏器的auto AV search功能可有效减少非必须的心室起搏,促进自身心室激动。     

房室间期自动搜索功能对心室起搏及心功能的影响

目的 观察自动AV间期搜索功能双腔起搏器减少心室起搏和高频心房事件的效果及对心功能的影响.方法 60例置入DDD/R起搏器的患者（有AV搜索功能30例,无AV搜索功能30例）,术后1年内程控获取右室起搏百分比、高频心房事件,检查超声心动图,测试血浆利钠肽（BNP）值.结果 有AV搜索功能组术后6个月和12个月右室起搏百分比明显小于无AV搜索功能组[（21.2±6.0）％比（78.3±7.5）％,（19.1±6.5）％比（73.4±7.9）％,P均＜0.05）.AV搜索功能组左室射血分数、左室Tei指数均明显改善（0.57±0.03比0.53±0.05,0.48±0.15比0.68±0.20,P均＜0.05）;BNP水平明显降低[（75.2±34.5）pg/ml）比（37.0±16.4）pg/ml,P＜0.05];高频心房事件也显著减少[（42±10）次比（19±11）次,P＜0.05].结论 AV自动搜索功能起搏器可有效减少不必要的右室起搏及高频心房事件,改善血流动力学效应.     

Zephyr5826起搏器心房自动阈值管理的临床观察

目的动态观察Zephyr5826起搏器心房自动阈值管理(ACM)功能的开启情况、准确性及安全性。方法选取置入Zephyr5826起搏器患者68例,于置入术后第1,7天及1,2,3,6个月时随访程控,观察ACM功能的开启情况,手工测试心房起搏阈值并与ACM功能测定的值进行比较。结果 68例均完成随访。随访期内35例(51.50%)成功开启ACM功能,其中术后第1,7天及1,2,3个月时开启例数分别为14例(20.6%)、21例(30.9%)、26例(38.2%)、28例(41.2%)和32例(47.1%)。手工测试与ACM测试的心房阈值无差异。33例因起搏器自动测定心房刺激除极波(ER)过小不推荐开启ACM功能。随访期间心电图及动态心电图(Holter)均未见心房失夺获及感知不良。与普通电压和高电压起搏相比,自动阈值管理功能在心房输出方面分别节省50%,88%的能量消耗。结论 Zephyr5826起搏器ACM功能可以安全有效的应用低能量起搏心脏。部分患者术后因起搏器测定心房ER过小未能开启ACM功能,但在随访过程中ACM的开启比例逐渐升高。     

对心室起搏管理的再认识

心室起搏管理(MVP)这一功能为美敦力公司开发,MVP模式下,双腔起搏器的基本起搏模式为AAI(R),但起搏器的心室通道具有感知功能和备用起搏功能,起搏模式可以在AAI(R)和DDD(R)之间转换。在AAI(R)起搏模式下,单个心房激动未下传激动心室并不触发起搏器发生模式转换,也不触发起搏器发放心室脉冲(VP),心室备用脉冲的发放时间为心房逸搏间期计时结束后的80 ms处;如果连续4个P波中有2个不能下传激动心室,则AAI(R)起搏模式将自动转换为DDD(R)起搏模式。MVP功能进行自身房室传导搜索时的心室漏搏会增加患者的不适,心室漏搏造成的长短周期序列可能会诱发心律失常,即使起搏器能搜索到自身房室传导,但如果自身房室传导间期过长,则失去了房室顺序收缩对心输出量的改善。如存在心房起搏功能或心房感知功能不良会造成房室不同步。病窦综合征患者植入有MVP功能的起搏器后,AAI(R)起搏模式下如果心房通道发生超感知,会导致心室漏搏。MVP功能打开时会抑制心室安全起搏功能发挥作用。如室性早搏或交界区早搏的QRS波位于心房起搏后80 ms内,不会被起搏器感知,使起搏器判断错误,起搏器误认为心室发生了漏搏,触发心室备用脉冲在心房逸搏间期结束后80 ms处发放。上述缺点限制了MVP功能在临床上的使用,如能对MVP功能做一改进,进行自身房室传导搜索时如果在两个心房事件间期的50%处或心房事件后一定时间处(如350 ms时)仍未搜索到自身房室传导时,起搏器发放心室备用脉冲,可能会减少MVP的不良影响,这一改进和AV Search的区别在于房室搜索是逐渐延长还是突然延长。     

如何分析起搏心电图的房室间期

起搏心电图的起搏的房室间期(PAV)和感知的房室间期(SAV)间期并不是固定不变的,在心房感知功能不良、频率适应性AV延迟、AV滞后、心室安全起搏、非竞争性心房起搏、心室自动测阈值、起搏器特殊的程控模式、心室起搏管理等情况下,实际的PAV和SAV间期可能和程控值不同。随着起搏器现代功能的日益增多,多数情况下PAV和SAV间期和程控值不同并不是起搏器功能障碍,而是起搏器的特殊功能在发挥作用。     

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。     

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。     

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。     

Circadian pattern of atrial pacing threshold in the young.

AIM: The aim of this study was to evaluate the circadian variation of atrial pacing threshold in young patients. METHODS AND RESULTS: Atrial Capture Management (ACM) algorithm is a Medtronic EnPulse pacemaker (PM) feature that uses two algorithms: atrioventricular conduction (AVC) (atrial pacing and spontaneous AVC) and atrial chamber reset (ACR) [intrinsic atrial activity with atrioventricular block (AVB)]. For this prospective, non-randomized study, ACM automatically measured and recorded thresholds every 4 h. Data are reported as median (range) or mean +/- SD. In 2004-05, 14 consecutive patients (11 males, 79%), aged 12 years (1 day-24 years) received an EnPulse DDD/R PM for AVB (eight patients, 57%) or sinus node dysfunction. A new pacing system was implanted in eight patients (57%) and a replaced PM in six patients. Epicardial leads were implanted in 10 patients (71%). The follow-up duration is 11 (1-18) months: 9742 threshold measurements were attempted (6328 AVC, 3414 ACR), of which 3797 (39%) were successful (1807 AVC, 29%, 1990 ACR, 58%) in 11 (79%) patients. Three infants had no successful measurements. Measurement success was 42 +/- 34% (AVC 27 +/- 39%, ACR 41 +/- 29%). Higher thresholds were found between 00.00 and 12.00 a.m. and lower between 12.00 and 20.00. CONCLUSION: Young patients show a circadian variability of atrial threshold with higher thresholds between 00.00 and 12.00.     

Acute performance evaluation of a new ventricular automatic capture algorithm.

AIMS: This study evaluated the acute clinical performance of a new ventricular automatic capture algorithm developed to work with all lead types and pacing vectors. METHODS AND RESULTS: During regular pacemaker implant or replacement, AutoThreshold and manual threshold tests were performed in ventricular unipolar (UP) and bipolar (BP, if applicable) pacing using a customized external prototype INSIGNIA pacemaker. The success rate and accuracy of two different modes (commanded and ambulatory) of the automatic capture algorithm were used to evaluate the performance. Loss-of-capture events (two consecutive non-captured beats without backup pacing) were used to assess safety. Data of 53 patients (33 DDD/20 VVI) from four medical centres were analysed. Tested leads included 43 BP and 10 UP from nine manufacturers, and seven had electrodes with low polarization. The rate of successful commanded and ambulatory AutoThreshold tests was 96 and 94%, respectively, with an average absolute threshold difference compared with manual threshold of < 0.1 V at 0.4 ms (commanded 0.07 +/- 0.07 V and ambulatory 0.08 +/- 0.07 V). There was no significant difference in performance between UP/BP pacing, polarization, and lead type. No loss-of-capture event was observed. CONCLUSION: When successful, the ventricular automatic capture algorithm accurately determined pacing thresholds in either a UP or BP pacing configuration among all leads tested.     

Selective increase of ventricular pacing threshold with complete exit block following DC cardioversion in a patient with a dual chamber pacemaker

We report the case of a 78-year old patient with a dual chamber pacemaker, who was admitted for cardioversion of atrial tachycardia. Transthoracic DC shock of 160 J was followed by transient loss of ventricular capture with complete exit-block and severe nodal bradycardia. Subsequent analysis of stimulation thresholds revealed a marked rise in the ventricular threshold only, whereas atrial threshold was unchanged. The selective dysfunction of ventricular capture is most likely caused by current-induced tissue damage at the electrode-endomyocardial interface by preferential shunting of high electrical energy into the ventricular lead as compared to the atrial lead. High output pacing prior to elective DC cardioversion is recommended to ensure consistent capture, particularly in pacemaker-dependent patients, and careful evaluation of pacemaker function after shock delivery should performed.