长期心房与心室起搏对心房颤动发生率的影响

目的 为比较长期心房与心室起博心房颤动(Af)发生率的影响.方法 选择国内较大的三家医院1992年至1994年期间内安装人工心脏起搏器的病人,随访观察心房起搏(安装了AAI、AAIR、DDD及DDDR起博器)和心室起搏(植入了VVI或VVIR起搏器)Af的发生情况.结果 发现心室搏Af发生有逐年增加的趋势,Af4年发生率为33%,5年为41%,6年为52%.单纯心房起搏或房室顺序起搏Af发生率3%,而单纯心室起搏的病人中约40%出现Af,明显高于心房起搏组,P<0.01.结论 研究证明心房起搏可以减少Af的发生,为起搏方式的选择提供了一个客观根据,提示在临床实践中应该尽量选择AAI和DDD等生理性起搏方式.     

心房颤动的起搏治疗进展

心房颤动是室性早博后第二位的心律失常,起搏治疗心房颤动目前已成为难治性心房颤动的有效治疗途径。本文结合文献对心房颤动起搏治疗的方法、研究状况、适应证、优缺点作一综述。     

他汀类药物预防起搏器术后阵发性心房颤动的作用

目的观察他汀类药物预防病态窦房结综合征患者起搏器术后阵发性心房颤动（房颤）的作用。方法选择因病态窦房结综合征植入起搏器的患者68例,随机分为他汀治疗组和对照组。术后仅他汀组服用阿托伐他汀20rng,每晚1次,两组其他基本情况相似。于术后3、9、15、21个月程控起搏器,调出起搏器存储的有关阵发性房颤信息,进行统计分析。结果与对照组比较,起搏器术后服用他汀类药物9个月,阵发性房颤发生率降低;继续服用他汀类药物至15个月,阵发性房颤发生率及房颤负荷均明显降低;持续服用他汀类药物21个月,阵发性房颤发生率和房颤负荷显著低于对照组患者。结论病态窦房结综合征患者植入起搏器术后,长期服用他汀类药物能够减少阵发性房颤发作。     

Selective activation of the “b” splice variant of phospholipase Cβ1 in chronically dilated human and mouse atria

Atrial fibrillation (AF) is commonly associated with chronic dilatation of the left atrium, both in human disease and animal models. The immediate signaling enzyme phospholipase C (PLC) is activated by mechanical stretch to generate the Ca²⁺-releasing messenger inositol(1,4,5)trisphosphate (Ins(1,4,5)P₃) and sn-1,2-diacylglycerol (DAG), an activator of protein kinase C subtypes. There is also evidence that heightened activity of PLC, caused by the receptor coupling protein Gq, can contribute to atrial remodelling. We examined PLC activation in right and left atrial appendage from patients with mitral valve disease (VHD) and in a mouse model of dilated cardiomyopathy caused by transgenic overexpression of the stress-activated protein kinase, mammalian sterile 20 like kinase 1 (Mst1) (Mst1-TG). PLC activation was heightened 6- to 10-fold in atria from VHD patients compared with right atrial tissue from patients undergoing coronary artery bypass surgery (CABG) and was also heightened in the dilated atria from Mst1-TG. PLC activation in human left atrial appendage and in mouse left atria correlated with left atrial size, implying a relationship between PLC activation and chronic dilatation. Dilated atria from human and mouse showed heightened expression of PLCβ1b, but not of other PLC subtypes. PLCβ1b, but not PLCβ1a, caused apoptosis when overexpressed in neonatal rat cardiomyocytes, suggesting that PLCβ1b may contribute to chamber dilatation. The activation of PLCβ1b is a possible therapeutic target to limit atrial remodelling in VHD patients.     

The effect of VVI pacing on P-wave dispersion in patients with dual-chamber pacemakers

The incidence of atrial fibrillation is higher in patients with VVI pacing mode than DDD pacing mode, but the likely mechanism is not clearly understood. We aimed to evaluate whether short-term VVI pacing increases inhomogeneous atrial conduction by using P-wave dispersion. Forty-seven patients (32 men, 15 women, mean age 54 ± 13 years) with DDD pacemakers were enrolled in this study. Twelve-lead surface ECGs were obtained in all patients during VDD pacing after an observation period of 1 week. The mode was then changed to VVI and 12 lead surface ECGs were obtained after another 1-week observation period. P-wave durations were calculated in all 12 leads in both VDD and VVI pacing modes. The difference between the maximum and the minimum P-wave duration was defined as the P-wave dispersion (PWD = P_max − P_min). P-wave maximum duration (P_max) calculated in VVI pacing mode was significantly longer than in VDD pacing mode (128 ± 19 vs 113 ± 16 ms, P < 0.001). There was no significant difference in the P-wave minimum durations (80 ± 13 ms vs 79 ± 12 ms, P = 0.7) between VVI pacing and VDD pacing. The P-wave dispersion value was higher in the VVI pacing mode than in the VDD pacing mode (48 ± 8 ms vs 34 ± 7 ms, P < 0.001). Short-term VVI pacing induces prolongation of P_max and results in increased P-wave dispersion, which might be responsible for the development of atrial fibrillation more frequently in these patients than in those with the VDD pacing mode.     

递进式个体化心房基质消融治疗心房颤动

目的 以肺静脉电学隔离为终点的心房颤动（房颤）消融术式的疗效难以令人满意。本研究旨在探索规范化的递进式个体化心房基质改良消融术治疗房颤的方法。方法 124例患者（男性96例,女性28例）,年龄27-76（53．6±8．7）岁。其中92例为阵发性房颤,32例为持续性／永久性房颤。若无自发房颤则在心房进行持续递增的快速刺激（频率200—600次／min）诱发房颤。均在非接触式标测观察房颤时心房激动情况,将最常激动部位做为房颤基质进行改良消融,并根据消融后重复等电位标测的结果作出递进式调整,直至房颤被终止不再被诱发。结果 在既不隔离肺静脉也不寻求碎裂电位的情况下,87．1％（108／124）的房颤消融转复为窦性心律,其余被转为非典型心房扑动（房扑）或房性心动过速（房速）。可将消融灶分为3种类型,其中以7字形的A型线性消融最关键,71．6％的阵发性房颤可被A型消融终止且不再被诱发,而68．8％的持续性／永久性房颤则需通过B型消融终止。随访（21．6±5．3）个月,90．3％（112／124）的患者不服药亦无房颤发生。其余9．7％（12／124）的患者有顽固性非典型房扑／房速,其中仅1．6％（2／124）的患者伴有阵发性房颤。结论 递进式的心房基质消融术可以将房颤有效地转复为窦性心律,并有满意的远期疗效。此种术式简单易行有望在NavX和Carto标测下复制。     

Mortality in patients with atrial fibrillation has significantly decreased during the last three decades: 35 years of follow-up in 1627 pacemaker patients

Aim: The impact of atrial fibrillation (AF) on mortality is not fullyunderstood. We therefore sought to investigate long-term effectsof AF on mortality in patients with the need for pacemaker (PM)therapy. Methods and results: A total of 1627 PM recipients with AF at implantation were followedin a single-centre, longitudinal study for up to 35 years. Baselinefactors affecting survival and long-term follow-up were analysed.A total of 7362 patient-years of follow-up (PM implanted between1971 and 2000, followed until 31 December 31 2005) were analysed.Female PM recipients lived significantly longer than male (P= 0.025; mean survival 91.9 vs. 72.1 months) despite older ageat time of inclusion. Mean survival times almost doubled forpatients implanted in the last decade, with 139.8 months inthe nineties vs. 66.8 months in the seventies and 75.7 monthsin the eighties (P < 0.001). Male gender, age at implantation,non-syncopal bradycardia, and decade of implantation influencedsurvival. Conclusion: Life expectancy in AF patients after PM implantation has doubledwithin the last three decades, with a mean survival in the overallpopulation of 7.6 years for women and 6.0 years for men. Survivalis influenced by several simple baseline characteristics, whichmay help to identify patients with very long survival times.     

How Do Physicians Define “Light,”“Moderate,” and “Heavy” Drinking?

Although widely used, terms associated with consumption of alcohol–such as "light,""moderate," and "heavy"—are unstandardized. Physicians conveying health messages using these terms therefore may impart confusing information to their patients or to other physicians. As an initial attempt to assess if informal standardization exists for these terms, the present study surveyed physicians for their definitions of such terms. Physicians operationally defined "light" drinking as 1.2 drinks/day, "moderate" drinking as 2.2 drinks/ day, and "heavy" drinking as 3.5 drinks/day. Abusive drinking was defined as 5.4 drinks/day. There was considerable agreement for these operational definitions, indicating there is indeed an informal consensus among physicians as to what they mean by these terms. Gender and age did not influence these definitions, but self-reported drinking on the part of physicians was a factor. We also asked physicians for their opinions regarding the effects of "light,""moderate," and "heavy" drinking on health in general and specifically on health-related implications for pregnant women, and whether they felt their patients shared these beliefs.     

Cardiac resynchronization therapy: “Nonresponders” and “hyperresponders”

BACKGROUND: Cardiac resynchronization therapy (CRT) is a recognized treatment modality for patients with dilated cardiomyopathy (DCM), left bundle branch block, and severe cardiac failure. However, 30% of patients are "nonresponders." Intriguingly, the opposite case has not been reported until recently: Do some patients treated with CRT have a "complete" recovery and thus can be considered "hyperresponders"? OBJECTIVE: The purpose of this study was to investigate patients treated with CRT who have a "complete" functional recovery, with normalization of left ventricular function after therapy. METHODS: Eighty-four consecutive patients with DCM, sinus rhythm, and left bundle branch block in New York Heart Association functional class III and IV who were implanted with a CRT device were prospectively followed. Patients were considered to be "hyperresponders" if they concurrently fulfilled two criteria: functional recovery and left ventricular ejection fraction > or = 50%. RESULTS: Among the 84 patients with DCM, 11 (13%) were "hyperresponders" within 6 to 24 months after CRT (left ventricular ejection fraction increased from 25% +/- 8% to 60% +/- 6.5%, P = .001). Comparison of baseline parameters between "hyperresponders" and the remaining patients showed that only etiology of the DCM was statistically discriminative. All "hyperresponders" belonged to the group of patients with nonischemic DCM (18% vs 0%, P = .05). CONCLUSION: In a subset of patients successfully implanted with a CRT device, "complete" functional recovery associated with normalization of LV function was observed, giving rise to the concept of "hyperresponders." This finding is observed exclusively in the subgroup of patients with nonischemic DCM and suggests that left bundle branch block may be the causal factor of DCM in this subgroup of patients.     

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。     

What is the real atrial fibrillation burden after catheter ablation of atrial fibrillation? A prospective rhythm analysis in pacemaker patients with continuous atrial monitoring.

AIMS: Rhythm follow-up after catheter ablation of atrial fibrillation (AF ablation) is mainly based on Holter electrocardiogramm (ECG), tele-ECG or on patients symptoms. However, studies using 7-day Holter or tele-ECG follow-up revealed a significant number of asymptomatic recurrences. Thus, the aim of this study was to analyse continuous atrial recordings in pacemaker patients with an incorporated Holter function before and after AF ablation in order to determine all AF recurrences and thereby the 'real' success rates. METHODS AND RESULTS: The study comprised 37 patients (64.6 +/- 10 years) with prior pacemaker/implantable cardioverter defibrillator (ICD) implantation including an atrial Holter function referred for AF ablation. Holter data were obtained and correlated to patients' symptoms before and every 3-month after AF ablation. AF recurrence was defined as an atrial high frequency episode of less than 330 ms (180 b.p.m.) lasting longer than 30 s. The ablation procedure consisted of pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (PAF, n = 20) and additional substrate modification aiming arrhythmia termination in patients with persistent or inducible AF after PVI as well as in patients with a history of long-lasting persistent AF (PersAF, n = 17). The mean atrial Holter monitoring period was 7.4 +/- 3.3 months before and 13.5 +/- 4.2 months after ablation with an overall AF burden of 33.7% prior to ablation. During follow-up, AF burden decreased from 17.3-0.65% (P = 0.001) in PAF patients and from 57.4 to 13.9% (P = 0.024) in patients with PersAF. Complete AF freedom was observed in 85% (17 patients) of PAF patients and 59% (10 patients) in patients with PersAF. The absence of symptoms correlated well with documented freedom of AF. CONCLUSION: In the present study we could show, that freedom from AF can be achieved by catheter ablation in a high percentage of patients even with PersAF. Continuous atrial monitoring reveals AF ablation success rates comparable with those assessed by clinical evaluation. Symptomatic freedom of AF correlated well with the actual freedom of AF at least in this highly symptomatic patient cohort.     

射频消融并植入心脏起搏器对房颤患者生活质量及心功能的影响

目的:研究射频消融阻断房室传导同时植入永久性人工心脏起搏器对老年心房颤动(房颤)患者生活质量及心室结构和功能的影响。方法:2005年1月至2007年2月,7例老年房颤患者在长征医院接受射频消融阻断房室传导同时植入永久性人工心脏起搏器。术前及术后随访平均(7.7±4.9)月时进行生活质量问卷调查及心脏超声检查。结果:患者术后心悸、气短、头晕、胸痛评分较术前显著增加,分别提高120%、104%、94%和25%(P均0.01);总生活质量评分显著改善(P0.01)。与术前相比,7例患者术后室间隔舒张末期厚度(IVSTd)[(11.6±2.3)mm∶(9.1±1.4)mm]、室间隔收缩末期厚度(IVSTs)[(17.1±5.1)mm∶(11.8±1.2)mm]、左心室后壁舒张末期厚度(LVPWTd)[(11.0±2.1)mm∶(9.1±1.4)mm]、左心室后壁收缩末期厚度(LVPWTs)[(16.3±1.9)mm∶(12.2±0.8)mm]显著减小(P均0.05)。3例植入房室全能型起搏器(DDD)的患者,术前后左室射血分无明显变化。心室按需型起搏器。6名患者术后左室收缩末期内径(LVEDs)较术前显著增大[(30.0±6.4)mm∶(34.0±6.4)mm,P=0.01]。无起搏失灵、起搏电极脱位、囊袋感染及起搏综合征等并发症。结论:对于症状严重、药物疗效差或不能耐受药物治疗的老年心房颤动患者,射频消融阻断房室传导同时植入永久性人工心脏起搏器能显著减轻症状,提高生活质量。     

Simulator training: The bridge between “primum non nocere” and “learning by doing”

• Simulator training provides practice for trainees without exposing patients to potentially higher‐risk operators early in their training.
• This study suggests that simulator training shortens the learning curve for femoral access and reduces complications.
• Commercial availability of inexpensive, realistic simulators would aid medical education and reduce the risk posed to patients.

     

心房颤动起搏治疗的临床试验与研究现状

本文综述了起搏治疗和预防心房颤动(简称房颤)的主要临床试验和研究进展,包括生理性起搏、双房起搏、右心房多部位起搏、心房特殊位点起搏、起搏预防程序、心腔内电复律等。