起搏器自动化功能对右室起搏比率及心功能的远期影响

目的观察具备起搏模式策略和AV间期延长的策略功能的起搏器(Adapta)的远期临床效果。方法 39例患者随机分组,置入具有自动化功能的Adapta起搏器(实验组,n=20)和其它类型双腔起搏器(对照组,n=19)。并分别在置入前及置入后1,2年进行随访。随访中观察两组的右室起搏比例、心功能(纽约心功能分级、血脑钠肽)、左房内径(LAD)、左室舒张末内径(LVEDD)、左室射血分数、持续性心房颤动发生率及生活质量等的变化。结果置入双腔起搏器术后1年及2年,与对照组比较,实验组心室起搏比例均明显降低(38.21%±46.01%vs 92.52%±2.70%;36.22%±73.09%vs 91.78%±7.63%,P均<0.05)。置入术后2年,对照组与实验组及与自身术前比较,LAD,LVEDD增大(LAD:43.11±7.08 mm vs 39.01±3.72 mm,40.02±4.70 mm;LVEDD:53.60±6.91 mm vs 47.71±4.79 mm,46.57±3.99 mm,P均<0.05)。其他指标两组无明显差异。结论起搏器自动化功能可以有效降低心室起搏比例、保护心功能。     

双腔起搏器自动房室间期搜索功能对心房颤动发生的影响

60例置入双腔起搏器患者,分为房室间期搜索（Search AV）组（n=27）和非Search AV组（n=33）。术后6个月Search AV组较非Search AV组心房颤动（简称房颤）发生减少,房颤负荷降低。术后1年Search AV组房颤负荷仍低于非Search AV组。术后6个月及1年非Search AV组心室起搏比例高于Search AV组。心室起搏比例与房颤负荷正相关（P〈0. 05）。结论：双腔起搏器Search AV功能可明显减少心室起搏比例,降低房颤负荷,减少房颤发生。     

心脏起搏器自动化功能对老年患者心功能的影响

目的观察具有自动AV间期搜索和起搏模式策略自动化功能的双腔心脏起搏器对老年患者减少心室起搏的有效性。方法选择置入DDD/R型双腔心脏起搏器的老年病态窦房结综合征(SSS)患者123例,分为实验组66例,平均年龄(76.5±6.8)岁,置入具备自动AV间期搜索和模式策略功能的美敦力公司Adapta系列起搏器;对照组57例,平均年龄(73.1±7.4)岁,置入不具备上述2种功能的美敦力公司Sigma AED、MED系列起搏器。术后1年内随访,观察心功能(NYHA)、程控获取右心室起搏(VP)百分比、心脏彩色超声心动科进行左心房内径(LAD)、左心室舒张末内径(LVEDD)的测量,计算LVEF,抽血检测N末端前体钠尿肽(NT-proBNP)水平,并进行对比。结果与对照组比较,实验组术后1年VP百分比降低[(39.7±35.2)%vs(91.7±2.6)%,P=0.02],LVEDD、LAD、LVEF均明显改善,差异有统计学意义[(51.5±3.9)mmvs(53.9±3.6)mm,(38.2±2.6)mmvs(42.0±4.5)mm,(54.8±7.7)%vs(50.1±12.3)%,P<0.05,P<0.01),实验组术后1年NT-proBNP水平较对照组明显降低[(180.2±19.4)ng/Lvs(269.2±23.6)ng/L,P<0.01]。结论具有起搏自动AV间期搜索和模式策略自动化功能的双腔起搏器可减少老年SSS患者VP百分比,改善心功能。     

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。     

不同心室起搏策略对病窦综合征患者心室起搏百分比及心功能的潜在影响

目的观察不同心室起搏策略减少病窦综合征心室起搏百分比(Cum%VP)的效果以及潜在的心功能影响。方法将90例因病窦综合征植入美敦力Adapta系列起搏器的患者分为3组,分别程控为心室起搏管理(MVP)组、固定延长房室间期(LAVD)组和增强的房室间期自动搜索(Search AV+)组。随访12个月后,观察1不同起搏策略Cum%VP的差异;2血清脑利钠肽前体(NT-pro BNP)变化;3彩色超声心动图参数如左室射血分数(LVEF)、左室舒张末期内径(LVDd)及舒张早期的E峰/舒张晚期的A峰的E/A比值的变化。结果 MVP组Cum%VP为0.95%±0.44%,明显低于LAVD组的5.46%±0.23%及Search AV+组的6.74%±3.95%,P0.05。与MVP组比较,LAVD组及Search AV+组的血清NT-pro BNP、LVDd明显增加,LVEF较术前明显下降(P均0.05)。结论 MVP策略优于LAVD策略和Search AV+策略,能够显著减少病窦综合征患者Cum%VP,保护心功能。     

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。     

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.     

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.     

具有自动房室间期搜索功能的双腔起搏器的临床随访

目的: 观察具有自动房室(AV)间期搜索功能的双腔起搏器减少心室起搏的有效性及起搏器长期的参数变化及安全性。方法: 对两种DDD/R起搏器86例(有搜索功能40例,无搜索功能46例)患者术后半年内随访观察。结果: 有搜索功能组术后1、3、6个月右室起搏率明显小于无搜索功能组［(20±6)% vs. (78±12)%,(18±7)% vs. (73±9)%,(19±5)% vs. (76±9),均P<0.05］。两组起搏参数及患者心功能分级均无明显差异。随访期间未出现AV搜索功能障碍等情况。结论: 有AV搜索功能DDD/R起搏器可减少非必须的心室起搏,安全可靠。     

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.     

双腔起搏器自动房室间期搜索功能的临床随访观察

目的 观察双腔起搏器自动房室间期搜索功能(AV Search)减少心室起搏的有效性及对血流动力学和快速房性心律失常的影响.方法 对两种DDD/R起搏器97例(有AV Search功能47例,无AV Search功能50例)患者术后半年内随访观察.结果 有AV Search功能组术后1、3、6个月右心室起搏百分比明显小于无AV Search功能组[(19.2±5.6)%vs(80.4±10.2)%,(17.8±6.6)%vs(75.3±9.5)%,(17.4±7.3)%VS[76.2±8.6]%,P<0.05].有AV Search功能组心脏指数、每搏量、左心室舒张末内径、左心房内径及患者心功能分级均无明显改善(P>0.05);而左心窒射血分数则高于无AV Search功能组(P<0.05).高频心房事件也显著减少((31±9)vs(49±11),P<0.05].结论 有AV Search功能DDD/R双腔起搏器在减少非必须的心室起搏,改善血流动力学,减少高频心房事件方面优于与无AV Search功能DDD/R起搏器.     

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。     

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.     

Effect of continuous enhanced vagal tone on atrioventricular nodal and sinoatrial nodal function in humans

A constant intravenous infusion of phenylephrine (0.74 +/- 0.41 micrograms/kg/min) was given to 10 patients to cause a continuous augmentation in reflex vagal tone. After the infusion, the diastolic blood pressure increased from 76 +/- 7 to 89 +/- 11 mm Hg (p less than 0.01). The sinus cycle length and atrial-His (AH) interval were measured, and incremental atrial pacing was performed before and during phenylephrine infusion until atrioventricular (AV) nodal block was achieved. For each patient, the AV nodal function curve (i.e., the AH interval plotted as a function of the atrial pacing cycle length) was compared during both the control state and phenylephrine infusion; the AH intervals during each condition at chosen short (AHS) and long (AHL) cycle lengths were compared. The sinus cycle length increased during phenylephrine infusion from 941 +/- 294 to 1,115 +/- 347 msec (p = 0.013). The AH interval during sinus rhythm was not significantly prolonged (77 versus 82 msec, p = NS). The shortest atrial pacing cycle length yielding 1:1 AV nodal conduction increased during phenylephrine infusion from 412 +/- 120 to 575 +/- 211 msec (p less than 0.01). Of note, the degree of sinus cycle length prolongation did not correlate with the degree of prolongation in the shortest atrial pacing cycle length yielding 1:1 AV nodal conduction. The AV nodal function curve was shifted markedly to the right and only slightly upward.(ABSTRACT TRUNCATED AT 250 WORDS)     

Randomized pilot study of a new atrial-based minimal ventricular pacing mode in dual-chamber implantable cardioverter-defibrillators

OBJECTIVE: We hypothesized that a new minimal ventricular pacing mode (MVP) that provides AAI/R pacing with ventricular monitoring and back-up DDD/R pacing as needed during AV block (AVB) would significantly reduce cumulative percent ventricular pacing compared to DDD/R. BACKGROUND: Conventional DDD/R mode often results in high cumulative percent ventricular pacing that may adversely affect ventricular function and increase risk of heart failure and atrial fibrillation. METHODS: MVP was made operational in 30 patients with DDD/R implantable cardioverter-defibrillators (ICDs) and no history of AVB. Patients were randomized to one week each in DDD/R and MVP. Holter monitor recordings (ECG, intracardiac electrograms, and event markers) and device diagnostics were analyzed for cumulative % atrial paced (Cum%AP), cumulative percent ventricular pacing, and frequency and duration of DDD/R pacing back-up. Diaries were used to report symptoms. RESULTS: Age of the study population was 61 years +/- 12 years and 83% were male. Baseline PR interval was 204 ms +/- 32 ms and programmed AV intervals (DDD/R) were 200 ms +/- 50 ms (paced)/167 ms +/- 54 ms (sensed). Cum%AP was similar between MVP and DDD/R (47.9 +/- 37 vs 46.3 +/- 36). Cumulative percent ventricular pacing was significantly lower in MVP vs DDD/R (3.79 +/- 16.3 vs 80.6 +/- 33.8, P < .0001). Back-up DDD/R pacing during MVP operation due to transient AVB occurred in 10% of patients (9.3 +/- 7.4 [range 1-15] episodes/patient-day, duration 39.7 minutes +/- 156 minutes). Fifteen percent of AV intervals during MVP operation exceeded 300 ms. No significant symptoms were reported during MVP operation. CONCLUSIONS: MVP dramatically reduced cumulative percent ventricular pacing compared to DDD/R while maintaining AV synchrony and providing sensor-modulated atrial pacing support. Intermittent oscillations between MVP and DDD/R during transient AV block appeared safe and well tolerated.     

Unterstützung der spontanen atrioventrukulären Überleitung bei Patienten mit DDD(R)-Schrittmachern Effektivität und Sicherheit

AIM: In a prospective and randomized multicenter study using a cross-over protocol we compared the efficacy and the safety of the ELA medical mode-switch algorithm (DDD/AMC = DDD to AAI) to conventional DDD stimulation in patients with spontaneous AV conduction. PATIENTS AND METHOD: Forty-eight patients with a mean age of 67 +/- 13 years were included. Underlying heart disease was present in 54%. Pacemaker indications were paroxysmal AV block (21%), sick-sinus syndrome (46%), paroxysmal AV block + sick-sinus syndrome (31%) and tachycardia-bradycardia syndrome (8%). Patients were excluded from the study in case of a permanent 1st to 3rd degree AV block, a right bundle-branch block with QRS > 120 ms, severe coronary heart disease or idiopathic cardiomyopathy. The programming of the pacemaker was randomized to either DDD/AMC or DDD and was crossed over after 1 month. The AV interval (AVI) which was programmed in conventional DDD pacing was calculated as AVI = PR (or AR) + 30 ms at rest or as AVI = PR (or AR) - 50 ms during exercise. When the DDD/AMC mode was programmed, the AV interval was calculated automatically. We analyzed the AV interval, the frequency of ventricular pacing, the number of pacemaker-induced tachycardias, the number of atrial tachyarrhythmias, and the final programming which was left to the physician's choice. RESULTS: The AV interval after conventional DDD stimulation was 201 +/- 38 ms vs 195 +/- 28 ms with DDD/AMC (p = ns). Ventricular stimulation was significantly less often in the DDD/AMC mode than in the DDD mode (15 +/- 17% vs 48 +/- 37%, p < 0.001). Thereby the DDD/AMC algorithm led to a 69% reduction of ventricular pacing which means an approximately 5.5 months prolongation of the battery lifetime. There was no significant difference in the incidence of pacemaker-induced tachycardias. At the end of the study 77% of the physicians programmed the DDD/AMC mode. CONCLUSION: The analyzed DDD/AMC mode-switch algorithm leads to a significant reduction of ventricular pacing in patients with spontaneous AV conduction or with only paroxysmal AV block. Thereby the battery lifetime is prolonged and the incidence of complications due to ventricular pacing can be reduced.     

右室起搏部位与比例对心室事件及心功能影响

目的观察不同起搏比例的右室间隔部（RVS）和心尖部（RVA）起搏对心室事件和心功能影响。方法纳入置入双腔起搏器术满1年的患者96例,按照起搏部位不同分为RVS起搏组（n=48）和RVA起搏组（n=48）,利用程控房室间期自动搜索功能的打开与关闭,结合患者自身反应,按照心室起搏（VP）比例分为VP≤10%组（16例）、VP11%～89%组（16例）、VP≥90%组（16例）。通过心脏彩超记录左室舒张末期内径（LVEDD）、左室射血分数（LVEF）;由起搏器程控仪询问心室高频事件（VHR）和室性早搏（PVC）。结果 RVA起搏比RVS起搏PVC增多,VHR发生率无差异;随VP比例增加,两组VHR和PVC减少,RVA起搏组LVEF下降、LVEDD增大。结论 RVS起搏较RVA起搏可减少PVC、延缓心功能减退;降低VP虽可延缓新功能减退但会造成PVC增加。     

Comparison of VVIR, DDD, and DDDR Pacing

In the past several years there has been continued improvement in pacemaker technology, resulting in the availability of a large variety of pacemaker generators and pacing modes. The introduction of single-chamber rate modulated pacemakers provided a further improvement in pacing therapy. With the recent introduction of dual-chamber rate responsive pacemakers, it is now possible to more closely restore physiological function with pacing in a large number of patients. In deciding which pacing mode is most beneficial to a given patient, it is essential to understand the various characteristics of the different pacing modes that are available. It is essential to have knowledge of the underlying electrophysiological characteristics of the patient and how they would be affected by the different modes available. The VVIR mode will control bradycardia and provide rate adaptation but at the expense of AV synchrony. The DDD mode will control bradycardia and provide AV synchrony, but will not provide rate adaptation in patients with chronotropic incompetence. The DDDR mode will control bradycardia, maintain AV synchrony, and provide far rate adaptation in the presence of chronotropic incompetence. The chronotropic response to physiological stress and/or pacemaker syndrome are major determining factors in the choice of the best pacing mode. The primary goal of pacing therapy is to restore the heart function as close as possible to normal. When at all possible, this should include provision of both AV synchrony and rate modulation. The DDDR mode is preferable in most patients since it is capable of providing both AV synchrony and rate response (except those with chronic supraventricular arrhythmias). The VVIR mode is as effective in patients who have chronic atrial fibrillation or frequent episodes of supraventricitar arrhythmias.     

Atrial Sensing and AV Synchrony in Single Lead VDD Pacemakers: A Prospective Comparison to DDD Devices with Bipolar Atrial Leads

INTRODUCTION: Single lead VDD pacing has offered an alternative to DDD systems in patients with isolated AV block. Up to now, however, the relative performance of these pacemaker systems was not systematically compared. METHODS AND RESULTS: Three hundred sixty patients who received either a VDD pacemaker (n = 180) or a DDD device (n = 180) with a bipolar atrial lead were investigated prospectively for a mean period of 30 +/- 13 months. Pacemaker function was analyzed by telemetry, Holter monitoring, and exercise ECG. Time of implantation and fluoroscopy was significantly lower with VDD devices (44.3 +/- 5.1 min vs 74.4 +/- 13.5 min and 4.6 +/- 2.5 min vs 10.3 +/- 5.6 min in DDD pacemakers, respectively). Intermittent atrial undersensing occurred in 23.3% of patients with a VDD pacemaker and in 9.4% with DDD devices (NS). The incidence of atrial tachyarrhythmias did not differ between the VDD (6.7%) and the DDD group (6.1%). Sinus node dysfunction developed in 1.9% of patients, but the vast majority (85.7%) of patients were asymptomatic. There was a tendency for a higher rate of operative revisions in the DDD group (6.1% vs 3.3% in VDD pacemakers, P = 0.15). Cumulative maintenance of AV-synchronized pacing mode was 94.9% in patients with VDD pacemakers and 92.1% with DDD devices (NS). CONCLUSION: With the benefit of a simpler implant procedure, long-term outcome of single lead VDD pacing is equivalent to DDD pacing in patients with AV block and preoperative normal sinus node function.