频率适应性起搏

生理性起搏旨在重建心脏的节律和激动顺序。较多需要植入起搏器的患者存在窦房结功能不良，对运动和情绪不能作出正常的心率反应，即变时功能不良；而有些患者[例如心房颤动（房颤）患者]的心房信号不适于房室跟踪起搏。这些问题使得人们去寻找心房以外的信号来改善起搏频率，促进了人工传感器（sensor）的发展并应用于起搏技术中。频率适应性起搏（rate adaptive pacing）是指起搏器通过传感器感知体内生理、生化及物理参数的变化随时自动调整起搏频率。传感器模拟正常窦房结的反应，满足运动和非运动的需要。[第一段]     

频率适应性起搏器的研究进展

频率适应性起搏器是起搏器发展史上的重大进展。现对频率适应性起搏器作简要介绍,并对近年来频率适应性起搏器传感器(特别是双感受器传感器)、算式和适应证的研究进展进行简要综述。     

频率适应性起搏器治疗冠心病患者运动耐量评价

频率适应性起搏器（rate adaptive pacemaker）具有运动时起搏频率相应加快，以适应机体代谢需求的特点，有良好的血流动力学效应。理论上讲，由于频率适应性心率的增加可导致心肌耗氧增加，诱发或加重冠心病心肌缺血的发生，对合并有冠心病心绞痛的患者植入频率适应性起搏器的处理是不适合的。为进一步了解频率适应性起搏器的临床可行性及疗效，     

心电图起搏频率异常增快的诊断思路

起搏频率是指1min内起搏器发放脉冲的次数,又称为基础起搏频率(Base Rate)。根据需要可通过程控仪调整、设定起搏频率。非频率适应型起搏器基础起搏频率恒定,频率适应型起搏器随着患者运动量的增加,起搏频率相应增快。单腔起搏器(AAI/VVI)如无自主心搏出现,依据程控的起搏频率发放脉冲。双腔起搏器随自主心房率的变化,可在多种起搏模式之间进行自动转换,与此同时,也增加了引发心室起搏频率过快的潜在因素。起搏器自动化功能的出现与发展,使起搏频率的变化也更加复杂。     

闭环刺激双腔频率适应性起搏器的临床应用

目的介绍感知体动和精神活动的闭环刺激双腔频率适应性起搏器的初步应用经验.方法植入第3d开启闭环刺激频率适应功能,患者进行坐卧位、散步、快走、上下楼、思考等活动,第7d动态心电图检查和起搏器程控.3个月后随访,重复上述活动和检查,对比分析结果.结果18例患者植入闭环刺激双腔频率适应性起搏器(Biotronik公司的Inos2CLSDDDR),心室起搏阈值0.3～0.7(0.4±0.3)V,R波振幅9.5～21.8(14.6±7.5)mV,阻抗520～870(610±78)Ω;心房起搏阈值0.3～0.8(0.5±0.3)V,A波振幅7.2～16.4(11.6±5.7)mV,阻抗510～872(697±92)mV.随访50～486(236±107)d,均为频率适应性双腔起搏,体力和脑力活动时起搏频率能按需增加.与植入时相比,频率适应功能增强且更加个体化.结论Inos2CLS除适应体动变化外,还能适应精神负荷变化,自动完成初始参数和昼夜频率调整,程控简单,随访方便.     

两种体动感知方式频率适应性起搏器的频率适应特点

通过运动试验和干扰试验，比较两种体动感知频率适应性起搏器（ＲＡＰＭ）的频率适应特点。结果显示：平板运动时，体动振动感知和体动加速度感知两种ＲＡＰＭ的起搏频率分别增加２３和２１ｐｐｍ（Ｐ均＜０．０５）；体动加速度感知ＲＡＰＭ的起搏频率随运动负荷增加而显著加快（例如踏车运动负荷为２５，５０和７５Ｗ时，起搏频率分别为８３±７，９７±２１，１１３±２３ｐｐｍ，与前一负荷相比Ｐ均＜０．０５），体动振动感知ＲＡＰＭ的起搏频率则因外界干扰误增２３～３２ｐｐｍ（Ｐ＜０．０５）。结果表明体动加速度感知ＲＡＰＭ的频率适应程度与运动负荷的相关性以及频率适应特异性均好于体动振动感知ＲＡＰＭ。     

可对情绪变化起反应的闭环频率适应性起搏器的临床应用

目的　目前应用以感知运动的传感器为基础的频率适应性起搏器,在患者发生情绪变化时不能够提高起搏频率,本组报道新近开发的可感知情绪变化的闭环频率适应性起搏器的临床应用。方法　７ 例患者,男性５ 例,女性２ 例,因窦房结变时功能障碍,植入双腔频率适应性起搏器,其传感器为感知心室电极周围血液及心肌阻抗的变化的闭环传感器,不仅在运动时,而且可在情绪激动时增加起搏频率。术后对患者在平卧体位进行紧张试验,以观察在患者情绪变化时起搏器的频率适应功能。测试以患者倒数数的方法使患者保持情绪紧张。结果　患者试验前,平均起搏频率为６４ｐｐｍ ,情绪紧张时起搏频率上升至平均８６ｐｐｍ 。结论　感知心肌阻抗变化的闭环频率适应性起搏器在患者情绪紧张时可有效地使起搏频率增加,满足生理需求     

一种以动脉血压为反馈信息的频率自适应起搏器

本文介绍一种新的以动脉舒张压的变化量为控制参量的频率自适应起搏器。在由卧位改变为立位的姿势变化过程中,当舒张压下降时,起搏频率增加,使得血压迅速回升,以此纠治直立性低血压。用舒张压的瞬时值与平均值之差表示舒张压的变化量,平均电路的时间常数为5秒。起搏器的基础频率设定为85次/分,最高动态频率为150次/分,最低动态频率为70次/分。该起搏器以体外起搏方式用于四条Ⅲ度房室传导阻滞的清醒狗,实验结果证明其效果良好。     

每分通气量感知频率适应性起搏器Meta Ⅱ－1204

目的：评价每分通气量感知频率适应性起搏器的生理性功能，简要介绍其工作原理。方法：５例患者埋植ＭｅｔａⅡ－１２０４型起搏器，术后程控为非频率适应性和频率适应性起搏方式，进行运动和干扰试验。结果：频率适应性起搏时运动起搏频率和心输出量分别较非频率适应性起搏增加５７％（１１０±１７比７０次／分）和４９％（１１．２±１．８比７．５±１．４Ｌ／ｍｉｎ），运动耐量则提高４０％（４５７±５５比３２４±４３秒）；频率适应启动时间为３６秒；摆动上肢加快起搏频率２３次／分（９３比７０次／分）。结论：ＭｅｔａⅡ－１２０４型起搏器可改善心动过缓者的运动耐量和心输出量，其起搏频率适应幅度与运动负荷相关性好，但频率适应速度较迟缓。     

闭环式情绪体动双项感知频率适应性起搏器的临床应用

目的频率适应性起搏器临床应用的主要类型是感知体动,但存在局限性。本组使用感知情绪、体动变化的闭环式频率适应性起搏器,可同时感知情绪及体动变化,相应增加或减少起搏心率,满足机体需求。 方法患者10例,全部为窦房结功能障碍者,置入双腔闭环式频率适应性起搏器(BiotronikINOS     

Benefits and limits of single chamber atrial pacing with adaptive rate

Twelve patients with isolated symptomatic sinus node dysfunction or bradycardia-tachycardia syndrome with atrial chronotropic incompetence during exercise testing were managed by single chamber rate responsive atrial pacing (AAIR) when AV conduction was normal, or by a dual chamber DDDR pacemaker programmed in the AAIR mode when AV conduction was abnormal, and followed up for 12.5 +/- 9.8 months. The patients were assessed clinically, by 3 monthly ECG and Holter recordings and comparative exercise tests in AAI and AAIR modes at the 6th month. One patient with an AAIR system was excluded at M21 because of symptomatic AV block requiring reimplantation of a DDD pacemaker. Ten of the 11 remaining patients are asymptomatic and have an excellent quality of life; one patient had invalidating symptoms on exercise attributed to the "AAIR pacemaker syndrome" which were corrected by reprogramming the pacemaker and modifying the medical therapy. The comparative exercise stress tests showed a significantly higher heart rate in the AAIR mode compared to AAI pacing at the initial and intermediate exercise levels (30 to 70 W); on the other hand, the heart rates were not significantly different at the highest exercise levels although in the AAI mode, the terminal acceleration sometimes occurred in junctional rhythm whereas it was usually an atrial paced rhythm in the AAIR mode. The total duration of exercise was longer in the AAIR mode (+22%; p less than 0.01) when the 8/11 patients with chronotropic incompetence during the baseline study were considered. The spike-R interval adapted normally to exercise in only one case: in the other patients, the interval remained constant or, in the worst of cases (N = 4), it increased paradoxically, to result in the "AAIR pacemaker syndrome": this phenomenon is observed mainly in patients treated by antiarrhythmics and/or betablockers. The AAIR mode would therefore seem to be a simple, effective and reliable method of treating patients with sinus node dysfunction and chronotropic incompetence; however, the failure of adaptation of the PR interval is a real limitation to its use and may constitute an argument in favour of the choice of a DDR pacemaker in these patients.     

Limitations of testing methods for evaluation of dual chamber versus single chamber adaptive rate pacing

As new modes of cardiac pacing are developed, it is important to determine if these modes offer additional benefits over already existing options. Comparisons between dual (DDDR) and single chamber ventricular (VVIR) rate-modulated pacing using standard exercise protocols have produced conflicting results.^1–4 Exercise duration alone does not appear to accurately reflect differences in cardiac efficiency and tissue perfusion. Similarly, maximal oxygen uptake tends to reflect exercise duration rather than cardiac performance. ⁵ This study was designed to compare the DDDR and VVIR pacing modes using measures of exercise duration and maximal oxygen uptake, as well as less frequently used parameters, including anaerobic threshold time, maximal carbon dioxide production, respiratory exchange ratio, cardiac output, and the ratio of cardiac output to oxygen uptake.     

频率自适应起搏器的临床应用和心电图特点

本文报告6例应用体动感知的(DDDR、VVIR)或呼吸感知的(AAIR、VVIR)频率自适应起搏器的临床经验和心电图特点。随访5～36月(平均19.7月)。结果症状皆消失,心功能改善,无合并症。     

单腔双感知和单腔单感知频率应答式起搏器临床应用分析(附62例随访报告)

目的　评价单腔双感知和单腔单感知频率应答式心脏起搏器的临床效应。方法　６２ 例（ 男２９ 例,女３３例） 病态窦房结综合征患者,年龄２０ ～７０ 岁,起搏器均为频率应答式起搏器,起搏电极１６ 例为单腔双感知（ 气动＋ 体动） ,４２ 例单腔单感知（ 体动式）,４ 例为单腔单感知（ 气动式） 。术后半年每月随访一次,半年后三个月随访一次,一年后３ ～６ 个月随访一次,随访内容包括ＨＯＬＴＥＲ。结果　６２ 例随访平均６ 年,无发生起搏综合征,临床症状明显改善,多数恢复生活自理能力和工作。动态心电图检查起搏功能良好。结论　单腔双感知和单腔单感知频率应答起搏器对比,当活动量或通气量增加时,起搏频率随之增加,其临床效果无明显差异。对于心动过缓合并房颤患者,建议采用单腔单感知频率应答起搏器已能达到目的。     

单左室起搏通过频率适应性房室延迟实现双心室再同步

目的探讨单左室起搏通过频率适应性房室延迟(RAAV)算法跟踪生理性房室延迟(AVD)实现双心室再同步的可行性及治疗慢性充血性心力衰竭(CHF)的效果。方法入选符合心脏再同步化治疗(CRT)Ⅰ类适应证并植入带RAAV功能的三腔或双腔起搏器的CHF患者64例,其中RAAV单左室起搏(LUVP)组(单左室组)32例,以标准双室起搏(BVP)组(标准双室组)32例为对照组。两组给予标准心脏超声优化,比较主动脉前向血流速度时间积分(AVI),左室射血分数(LVEF)、十二节段达峰时间标准差(TS-SD12)、主肺动脉射血前时间差(IVMD)、二尖瓣返流面积(MRA)、EA峰间距(E/A pd)、QRS波时限、年平均治疗费用、NYHA分级、6min步行试验(6MWT)等指标。结果与标准双室组比较,单左室组电池寿命更长[(7.8±0.3)年vs(4.5±0.2)年,P0.001],QRS波时限短[(136±10)ms vs(142±11)ms,P0.05],优化耗时较短[(20±4)min vs(52±8)min,P0.001],MRA更少[(3.1±1.1)cm~2 vs(3.7±1.2)cm2,P0.05],IVMD缩短[(64.2±12.8)ms vs(72.3±13.6)ms,P0.05],年均治疗费用低[(1.3±0.1)万元vs(2.2±0.2)万元,P0.001];AVI增加[(21.8±2.3)cm vs(20.6±2.1)cm,P0.05],余指标两组比较均无统计学意义(P0.05)。结论 RAAV单左室起搏可实现双室再同步,疗效不劣于标准BVP,且更符合生理性并降低治疗费用。     

Atrial adaptive rate pacing in sick sinus syndrome: effects on exercise capacity and arrhythmias.

OBJECTIVE--To test the hypotheses that adaptive rate atrial (AAIR) pacing: significantly increases maximal exercise capacity, and results in significant suppression of supraventricular and ventricular arrhythmia compared with fixed rate atrial (AAI) pacing. DESIGN--Prospective, randomised, single blind, crossover study with maximal treadmill exercise testing and 24 hour ambulatory electrocardiographic monitoring in AAIR and AAI modes. SETTING--Regional pacing centre. PATIENTS--30 consecutive patients (mean SD age 65 (12) years) with sick sinus syndrome who required permanent pacing, without evidence of conduction disturbance on 12 lead electrocardiograms or 24 hour ambulatory electrocardiographic monitoring and without other cardiovascular or systemic disease. INTERVENTIONS--Activity sensing or minute ventilation driven systems (AAI/AAIR) were implanted alternately. RESULTS--The mean (SD) peak heart rate in AAI mode was 122(28)v 130(22) in AAIR mode (p < 0.02) for the whole group and 104(17) v 120(5) (p < 0.003) for the patients with chronotropic incompetence. Exercise time was 12.3 (4.1) minutes in AAI and 12.3 (3.8) minutes in AAIR mode (NS) in the chronotropically incompetent patients. There were no significant differences in the Borg scores at peak exercise in AAI v AAIR mode in either group. The frequency per hour of atrial and ventricular arrhythmias showed no significant differences between the two modes in either the group as a whole or in the subgroups with chronotropic incompetence. CONCLUSION--AAIR pacing confers little benefit in sick sinus syndrome compared with AAI pacing.