心室起搏管理减少心室起搏比例的临床随访

目的探讨心室起搏管理(Managed Ventricular Pacing,MVP)对永久起搏器植入患者累计心室起搏比例(cumulative ventricular pacing proportion,Cum VP%)的影响。方法 (1)42例患者植入具有MVP功能的起搏器后,分别在常规DDDR和MVP两种工作状态下进行随访研究。其中先以常规DDDR状态工作1个月后,再以MVP状态工作1个月、6个月和12个月,分别计算累计心房起搏百分比(Cumulative atrial pacing proportion,Cum AP%)和Cum VP%;(2)计算在两种不同工作状态下Cum VP%小于40%的人数比例;(3)了解相关不良事件发生情况。结果 (1)传统DDDR模式工作1个月后,42例患者Cum VP%为(95.12±26.32)%。MVP模式工作下第1、6和12个月Cum VP%分别为:(19.63±44.80)%;(17.11±39.63)%;(15.62±46.80)%,(P0.05);(2)常规DDDR工作状态下Cum VP%小于40%的人数为0;而MVP模式下随访期间分别为(95.21±7.81)%;(96.73±3.20)%;(97.70±2.80)%(P0.05);(3)随访期间无相关不良事件发生。结论与传统DDDR模式相比,MVP模式可显著减少Cum VP%。     

一例心室起搏管理患者的心电图分析

1例因房室传导阻滞(AVB)植入具有心室起搏管理(MVP)功能起搏器患者的心电图,当房室传导功能正常时,以AAIR模式工作。出现间歇或短暂AVB,提供心室备用起搏。出现持续性AVB,转换为DDDR模式工作。具有MVP功能的起搏器可降低累计心室起搏百分比。     

心室起搏管理

心室起搏管理(MVP)是以心房为基础的双腔起搏模式,是最小化心室起搏策略的一种算法,可以克服不同起搏模式内在的限制。它以AAIR模式为基础进行心室事件的监测,当心室事件脱漏时,自动转换为DDDR模式;在DDDR模式下,定期进行自身房室传导功能的评估,如房室传导功能恢复,则再恢复AAIR模式。MVP可引起过长的房室间期、造成短长短联律间期引发恶性室性心律失常,一些特殊功能也会导致不良事件,但总的不良事件发生率较低。MVP是否能预防心房颤动或收缩功能不全、卒中的发生以及降低死亡率,还需进一步研究。     

心室起搏管理与精确心室起搏功能减少心室起搏的对照研究

目的比较心室起搏管理（management ventricular pacing,MVP）功能与精确心室起搏（refined ventricular pacing,RVP）功能减少右心室起搏的百分比的差异。方法 50例患者按照随机表1：1分成两组,每组25例,分别为MVP组和RVP组。MVP组为植入美敦力Adapt ADDR01起搏器,术后关闭MVP功能1个月;RVP功能组为植入Vitatron双腔起搏器TA1系列或CA3系列,术后关闭RVP功能1个月。1个月后开启MVP功能或RVP功能,术后1、3、6个月采用起搏器程控仪测试各项起搏参数,比较不同起搏功能下的心室起搏百分比。结果两组3个月后、6个月后心室起搏百分比中位数显著低于同组1个月后,差异均有统计学意义（MVP组：0.20vs.75.30,P〈0.01;0.10vs.75.30,P〈0.01。RVP组：6.00vs.88.40,P〈0.01;26.00vs.88.40,P〈0.01）。术后3个月、6个月MVP组的心室起搏百分比中位数低于RVP组,差异有统计学意义[0.20vs.6.00,P=0.02;0.10vs.26.00,P〈0.01]。结论 MVP功能在减少心室起搏百分比方面优于RVP功能,能够更有效的减少右心室起搏累计百分比。     

心室起搏管理功能降低病窦综合征患者高比例的右室起搏

目的评估具有心室起搏管理(MVP)功能的双腔起搏器对高比例右室起搏的病窦综合征(SSS)患者的疗效。方法 35例SSS患者,房室传导正常或合并间歇性房室传导阻滞(AVB),至少植入了两年双腔起搏器(DDD/R),并计划更换,入组前1个月以上的心室起搏比例超过40%。均植入具有MVP功能的双腔起搏器,随机程控MVP启动(MVP on组,n=17)或者关闭(MVP off组,n=18)。术前、术后6个月行血浆脑钠肽(BNP)测定;心脏超声测定左室收缩末期内径(LVESD),左室舒张末期内径(LVEDD),左室射血分数(LVEF);并于术后6个月程控起搏器了解右室起搏比例、心房高频事件。结果术前两组血浆BNP及LVESD、LVEDD、LVEF比较无显著差异(P>0.05);术后两组有关心脏超声指标无明显变化(P>0.05)。MVP on组术后较术前血浆BNP有明显下降(P﹤0.05),与MVP off组比较,MVP on组术后右室起搏百分比、心房高频事件发生率均有显著下降(2.6%±0.6%vs 48.4%±10.5%,15.7%±2.3%vs 62.0%±7.8%;P﹤0.01)。结论具有MVP功能的DDD/R起搏器能降低高比例右室起搏的SSS的右室起搏比例及心房高频事件的发生率。     

最小化心室起搏策略在病态窦房结综合征合并心衰患者中的临床应用

目的:比较心室起搏管理(managed ventricular pacing,MVP)和固定长房室间期(fixed long AV)两种最小化心室起搏策略,对双腔起搏器植入的病态窦房结综合征合并心衰患者中远期心脏结构和功能的影响. 方法:入选70例因病态窦房结综合征植入双腔起搏器的心衰患者,随机分为MVP组和固定长AV间期组,采用右室心尖部起搏方式,植入双腔起搏器后分别启用MVP模式和固定长AV间期模式.规范随访12个月后,比较两组患者心室起搏比例差异以及相应的心超参数变化和6 min步行试验结果. 结果:MVP组心室起搏比例较固定长AV间期组心室起搏比例明显减少(1.0％对11.3％,P＜0.01);固定长AV间期组左室射血分数术后12个月明显下降、E/A比值降低,而MVP组心功能指标则没有明显变化.术后12个月固定长AV组患者6 min步行距离明显缩短,而MVP组无明显缩短. 结论:因病态窦房结综合征植入双腔起搏器的心衰患者,在右心室心尖部起搏状态下,MVP模式较固定长AV间期模式对患者长期的心脏收缩和舒张功能负性影响较小.     

最小化心室起搏功能在病态窦综合征与房室传导阻滞患者中的应用分析

目的 比较分析最小化心室起搏中的心室起搏管理(MVP)功能在病态窦综合征(SND)与房室传导阻滞(AVB)患者中应用的差别.方法 入选接受双腔起搏治疗的症状性窦性心动过缓患者52例,并将患者分为SND组32例(62％)和AVB组20例(38％).首先关闭MVP模式,将起搏器程控调为生理型起博(DDD/R)模式,于3个月随访时将MVP模式打开.通过程控仪随访观察患者心房和心室的起搏比例、高频心房事件和房性心律失常(AA)负荷.结果 SND组患者MVP模式与DDD/R模式相比,心室起搏百分比(VP％)及心房起搏百分比(AP％),AA负荷百分比显著下降(P＜0.05),心房高频事件(AHR)两组比较差异无统计学意义.AVB组患者MVP模式与DDD/R模式相比,VP％显著下降,两组AA负荷百分比比较差异有统计学意义(P＜0.05),而两组AP％、AHR比较差异无统计学意义.结论 对于植入心脏起搏器的心动过缓的患者,MVP模式相较DDD/R模式可以显著地减少不必要的右心室起搏,无论是病窦综合征的患者还是房室传导阻滞的患者均可以从中获益.     

减少不良右室起搏的临床研究

目的观察心室起搏管理(Managing Ventricular Pacing,MVP)功能减少心室起搏百分比的效果。方法选择因病态窦房结综合征或房室阻滞而植入具有MVP功能的美敦力Adapta系列起搏器的患者共50例,分别程控为DDD模式和MVP模式,3个月后交叉程控为MVP模式和DDD模式,再随访3个月。结果两组患者DDD模式期间心室起搏百分比分别为40.5%(1.3%～90.1%)和39.9%(1.0～91.6%),两组患者MVP模式期间心室起搏百分比分别为5.8%(0～40.2%)和6.4%(0～32.4%)。MVP模式期间的心室起搏百分比明显低于DDD模式期间(p<0.05)。结论 MVP起搏模式能够降低因病态窦房结综合征或房室阻滞行永久性双腔人工心脏起搏器治疗患者的心室起搏百分比。     

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。     

双腔起搏器最小心室化起搏与房室间期优化起搏对心功能影响的比较

目的观察双腔起搏器最小心室化起搏功能与最佳房室间期优化对减少心室起搏和心功能的影响。方法30例符合标准患者入选。随机分为最小心室化起搏组(RVP,n=16)和超声优化下最佳房室间期组(OAV,n=14)。首先,分别在术后1周和术后6个月进行随访,术后6个月两组交叉(RVP转OAV,OAV转RVP),并于术后1年再次随访。随访中评估右室起搏比例、6 min步行试验、纽约心功能分级、明尼苏达州心力衰竭患者生活质量问卷和左室射血分数等指标。结果术后6个月随访,RVP较OAV组的右室起搏比例明显降低(P0.05)。至术后1年随访时,OAV转RVP组的右室起搏比例较RVP转OAV组明显降低(P0.05)。交叉前后的自身比较显示起搏器RVP功能打开后能显著降低右室起搏比例(P0.05)。其他各项指标在两组间都无显著差异(P0.05)。结论两种优化方式对于患者短期心功能无明显影响,但RVP较OAV能明显减少右室起搏比例。     

Percent ventricular pacing with managed ventricular pacing mode in standard pacemaker population

Aims: Unnecessary right ventricular pacing has deleterious effectsand becomes more significant when cumulative percent ventricularpacing (Cum%VP) exceeds 40% of time. The Managed VentricularPacing (MVP) mode has been shown to significantly reduce thepercent ventricular pacing compared to the DDD/R mode. Thisstudy assessed the percent of ventricular pacing in a standardpacemaker population programmed to MVP and for which patientsit is possible to achieve a Cum%VP 40%. Methods and results: Unselected, consecutive patients were implanted with a dualchamber pacemaker with a mean follow-up period of 76 days. TheCum%VP was calculated from device diagnostics between pre-hospitaldischarge (PHD) and the 1-month post implant visit. The medianCum%VP of 107 patients (age 67.2 ± 14 years; 53% male)who were programmed to MVP was 3.9%. The median Cum%VP was 1.4%in patients with sinus node disease (SND) and 28.8% in patientswith AV block (AVB). Cum%VP 40% was observed in 72% of allpatients, in 50% of AVB patients, and in 86% of SND patients. Conclusion: The MVP mode is capable of achieving a low percent of ventricularpacing in a standard pacemaker population with SND and AVB.In addition, 72% of patients in MVP mode demonstrated Cum%VP 40%.     

Eliminating right ventricular pacing may not be best for patients requiring implantable cardioverter-defibrillators

BACKGROUND: Excessive right ventricular (RV) pacing has been associated with adverse clinical outcomes in patients receiving pacemakers or implantable cardioverter-defibrillators (ICDs). It remains uncertain how much RV pacing is clinically deleterious. OBJECTIVE: This retrospective analysis assessed the relationship between the amount of RV pacing and the composite of all-cause mortality and heart failure hospitalization in all patients programmed DDDR in the Inhibition of Unnecessary RV Pacing with AV Search Hysteresis in ICDs (INTRINSIC RV) study. METHODS: Seven hundred fifteen patients consistently programmed to DDDR mode throughout follow-up (mean 11.6 months) were examined. The relationship between RV pacing tier and death and heart failure hospitalization was determined and compared with patient characteristics. RESULTS: Across the six RV pacing tiers, patients differed significantly with respect to age, clinical history of ventricular tachycardia, atrial fibrillation, and atrial flutter, and amiodarone use. When controlling for these baseline differences, the best outcome was seen in the group with RV pacing between 10% and 19% (2.8% event rate; n = 106). Increasing levels of RV pacing were generally predictive of higher event rates (death or heart failure hospitalization; P = 0.003), except for the group (n = 344) with the least amount of RV pacing (0-9%). This group exhibited poorer outcomes than otherwise expected (P = 0.016), with 8.1% of these patients experiencing an event. CONCLUSIONS: High levels of RV pacing are associated with heart failure hospitalization and mortality in a large ICD population. However, ICD patients with some RV pacing (10%-19%) exhibit lower event rates compared with those with very low levels (0-9%), possibly due to the physiologically appropriate nature of that RV pacing.     

Improved cardiac function and quality of life following upgrade to dual chamber pacing after long-term ventricular stimulation.

AIMS: Many patients with sinus node disease or atrioventricular block have previously received pacemakers with only ventricular stimulation (VVI or VVIR). This study aimed to investigate whether quality of life and cardiac function were affected by an upgrade to dual chamber pacing (DDDR or DDIR) following long-term ventricular stimulation. METHODS: After implantation of an atrial lead and a DDDR pulse generator, a randomized, double-blind crossover study was performed in 19 patients, previously treated with ventricular pacing for a median time of 6 X 8 years. Patients were randomized to 8 weeks with either VVIR or DDDR/DDIR pacing; after this time, the other mode was programmed for 8 weeks. At the end of each period, the patients' quality of life was evaluated and echocardiography was performed together with Holter monitoring and blood samples for brain natriuretic peptide. RESULTS: Sixteen of the patients preferred DDDR and two VVIR pacing (P=0 X 001); one was undecided. Seven patients demanded an early crossover while paced in the VVIR mode, vs none in the DDDR mode (P=0 X 008). Quality of life was higher in the DDDR mode in 11 of 17 modalities, reaching statistical significance for dyspnoea (P<0 X 05) and general activity (P<0 X 05). Echocardiography showed significantly larger left ventricular end-diastolic dimensions in the DDDR mode (P=0 X 01), whereas end-systolic dimensions did not differ. Left ventricular systolic function was significantly superior in the DDDR mode (mean aortic velocity-time integral: P<0 X 001) and left atrial diameter was significantly smaller in the DDDR mode (P=0 X 01). The plasma level of brain natriuretic peptide was significantly lower in DDDR mode (P=0 X 002). CONCLUSION: An upgrade to dual chamber rate adaptive pacing results in significantly improved quality of life and cardiac function as compared to continued VVIR stimulation and should thus be considered in patients with ventricular pacemakers who have not developed permanent atrial fibrillation or flutter.     

Multicenter, prospective, randomized safety and efficacy study of a new atrial-based managed ventricular pacing mode (MVP) in dual chamber ICDs

BACKGROUND: Ventricular desynchronization caused by right ventricular pacing may impair ventricular function and increase risk of heart failure (CHF), atrial fibrillation (AF), and death. Conventional DDD/R mode often results in high cumulative percentage ventricular pacing (Cum%VP). We hypothesized that a new managed ventricular pacing mode (MVP) would safely provide AAI/R pacing with ventricular monitoring and DDD/R during AV block (AVB) and reduce Cum%VP compared to DDD/R. METHODS: MVP RAMware was downloaded in 181 patients with Marquis DR ICDs. Patients were initially randomized to either MVP or DDD/R for 1 month, then crossed over to the opposite mode for 1 month. ICD diagnostics were analyzed for cumulative percentage atrial pacing (Cum%AP), Cum%VP, and duration of DDD/R pacing for spontaneous AVB. RESULTS: Baseline characteristics included age 66 +/- 12 years, EF 36 +/- 14%, and NYHA Class II-III 36%. Baseline PR interval was 190 +/- 53 msec and programmed AV intervals (DDD/R) were 216 +/- 50 (paced)/189 +/- 53 (sensed) msec. Mean Cum%VP was significantly lower in MVP versus DDD/R (4.1 +/- 16.3 vs 73.8 +/- 32.5, P < 0.0001). The median absolute and relative reductions in Cum%VP during MVP were 85.0 and 99.9, respectively. Mean Cum%AP was not different between MVP versus DDD/R (48.7 +/- 38.5 vs 47.3 +/- 38.4, P = 0.83). During MVP overall time spent in AAI/R was 89.6% (intrinsic conduction), DDD/R 6.7% (intermittent AVB), and DDI/R 3.7% (AF). No adverse events were attributed to MVP. CONCLUSIONS: MVP safely achieves functional atrial pacing by limiting ventricular pacing to periods of intermittent AVB and AF in ICD patients, significantly reducing Cum%VP compared to DDD/R. MVP is a universal pacing mode that adapts to AVB and AF, providing both atrial pacing and ventricular pacing support when needed.     

Managed ventricular pacing vs. conventional dual-chamber pacing for elective replacements: the PreFER MVP study: clinical background, rationale, and design

Aims: Several clinical studies have shown that, in patients with intactatrioventricular (AV) conduction, unnecessary chronic rightventricular (RV) pacing can be detrimental. The managed ventricularpacing (MVP) algorithm is designed to give preference to spontaneousAV conduction, thus minimizing RV pacing. The clinical outcomesof MVP are being studied in several ongoing trials in patientsundergoing a first device implantation, but it is unknown towhat extent MVP is beneficial in patients with a history ofventricular pacing. The purpose of the Prefer for Elective ReplacementMVP (PreFER MVP) study is to assess the superiority of the MVPalgorithm to conventional pacemaker and implantable cardioverter-defibrillatorprogramming in terms of freedom from hospitalization for cardiovascularcauses in a population of patients exposed to long periods ofventricular pacing. Methods and results: PreFER MVP is a prospective, 1:1 parallel, randomized (MVP ON/MVPOFF), single-blinded multi-centre trial. The study populationconsists of patients with more than 40% ventricular pacing documentedwith their previous device. Approximately, 600 patients willbe randomized and followed for at least 24 months. The primaryendpoint comprises cardiovascular hospitalization. Conclusion: The PreFER MVP trial is the first large prospective randomizedclinical trial evaluating the effect of MVP in patients witha history of RV pacing.     

Rate adaptive pacing in sick sinus syndrome: effects of pacing modes and intrinsic conduction on physiological responses, arrhythmias, symptomatology and quality of life

An atrial-based pacing mode is superior to ventricular constantrate demand pacing (VVI) mode in patients with sick sinus syndrome(SSS) by providing both rate adaptation and atrioventricular(AV) synchrony. The use of a non-atrial sensor to overcome chronotropicincompetence and preserve normal intrinsic AV conduction inpacemaker therapy for SSS was investigated in 15 consecutivepatients (mean age 66±2 years). All had intact AV conduction(antegrade conduction capacity >100 beats. min^–1 andan atrialpaced to intrinsic R interval of 220 ms). DDDR pacemakerscapable of being programmed into atrial rate adaptive (AAIR),dual chamber rate adaptive (DDDR) and ventricular rate adaptive( VVIR) modes were used Beginning with an acute study, arterialpressure was invasively assessed in each pacing mode duringphysiological stresses and low level exercise. In the ambulatoryphase, the incidence of ventricular pacing and arrhythmias (Holierrecording), diurnal blood pressure changes (ambulatory bloodpressure recording), and symptom and quality of life level (questionnairesand interviews) were compared. Despite similar heart rate changes during acute physiologicalstresses, a higher blood pressure was recorded during AAIR orDDDR pacing compared with VVIR pacing. Systolic blood pressureover 24 h was lower in the VVIR mode (122 ± 5 mmHg) thanAAIR/DDDR pacing (129 ± 61128 ± 6 mmHg, P<0.05).VVIR pacing was associated with a higher frequency of atrialand ventricular ectopics, with two patients developing paroxysmalatrial fibrillation. Ventricular pacing was used in a higherpercentage in the DDDR compared with the VVIR mode (64 ±11 and 39 ± 7%, P<0.03). VVIR pacing was associatedwith more palpitations, a lower level of general well beingand depression. Despite the use of a sensor to overcome chronotropic incompetence,VVIR pacing is a less satisfactory pacing mode for SSS. AlthoughAAIRIDDDR pacing may achieve similar haemodynamic and clinicalstatus, in patients with intact A V conduction, AAIR pacingmay be preferable by avoiding an abnormal ventricular activationpattern     

A randomized comparison of permanent septal versus apical right ventricular pacing: short-term results

OBJECTIVES: This study compared chronic right ventricular (RV) pacing at the septum versus apex. BACKGROUND: Chronic RV apical pacing may be detrimental to ventricular function. This randomized, pilot study examined whether, compared with apical, permanent septal pacing preserves cardiac function. METHODS: Ablation of the atrioventricular junction for permanent AF, followed by implantation of a DDDR pacemaker connected to two ventricular leads was performed in 28 patients. One lead screwed into the septum and another placed at the apex were connected to the atrial and ventricular port, respectively. Septum or apex was paced by programming AAIR or VVIR modes, respectively. Patients were randomly assigned, 4 months later, to pacing at one site for 3 months, and crossed over to the other for 3 months. New York Heart Association class, QRS width and axis, left ventricular ejection fraction (LVEF), exercise duration, and peak oxygen uptake were measured. Results in patients with LVEF > 45% and < or = 45% were compared. RESULTS: Septal pacing was associated with shorter QRS (145 +/- 4 msec vs 170 +/- 4 msec, P < 0.01) and normal axis (40 degrees +/- 10 degrees vs -71 +/- 4 degrees , P < 0.01). At 3 months, among patients with baseline LVEF < or = 45%, LVEF was 42 +/- 5% after septal pacing versus 37 +/- 4% after apical pacing (P < 0.001). CONCLUSION: In contrast to RV apical pacing, chronic RV septal pacing preserved LVEF in patients with baseline LVEF < or = 45%.     

Efficacy and tolerability of continuous overdrive atrial pacing in atrial fibrillation.

Overdrive right atrial pacing has been used to prevent atrial fibrillation, but its efficacy in atrial fibrillation prevention and the patient tolerability and quality of life during high rate pacing remain uncertain. The objective of this study was to test the effects of a consistent atrial pacing algorithm that automatically paced the atrium at 30 ms shorter than the sinus P-P interval for atrial fibrillation prevention. Fifteen patients with sick sinus syndrome implanted with a Thera DR (model 7940 or 7960, Medtronic Inc.) were randomly programmed to rate adaptive dual chamber pacing (DDDR) or DDDR + consistent atrial pacing mode, each for an 8-week study period. The efficacy of consistent atrial pacing was assessed by the number of automatic mode switching and the number of premature atrial complexes. Symptoms and quality of life were assessed by the SF-36 quality of life questionnaire and an atrial fibrillation symptom checklist. The percentage of atrial pacing increased from 57 +/- 32% to 86 +/- 28%. Overall, there was no significant difference in the number of automatic mode switching episodes between DDDR and DDDR + consistent atrial pacing (47 +/- 90 vs 42 +/- 87, P > 0.05), but a significant reduction in premature atrial complexes by 74.7% (P < 0.001). There was no undue increase in atrial rate by the DDDR + consistent atrial pacing mode versus DDDR (63 +/- 13 vs 70 +/- 7 bpm). There was no significant difference in quality of life scores and symptom severity on frequency between the two modes of pacing, but a trend towards a lower frequency of symptoms in the DDDR + consistent atrial pacing mode compared with baseline (29.5 +/- 10.2 vs 25.1 +/- 9.7, P = 0.07). An algorithm that provides consistent atrial overdrive pacing can suppress atrial fibrillation triggering premature atrial complexes without the need to increase the overall atrial rate compared with conventional pacing. The algorithm appears to be well-tolerated, but further studies are needed to address the clinical impact of this atrial fibrillation prevention algorithm.     

右室流入道间隔部螺旋电极导线与心尖部翼状电极导线起搏阈值随访分析

目的 :对比植入右室流入道间隔部螺旋电极导线与右室心尖部翼状电极导线 2组患者的起搏阈值。方法 :于植入时、植入后 2周、1个月、3个月、6个月、12个月、18个月、2 4个月测试起搏阈值 ,平均随访 12个月 (3～ 2 4个月 )。结果 :随访期间阈值无明显差别。结论 :应用螺旋电极导线固定于右室流入道间隔部永久起搏是可行的。