心房颤动发作时心房电极的置入

目的:探讨心脏起搏器置入术中心房颤动(房颤)发作时置入心房电极的方法和可靠性。方法:对24例具有心脏起搏器安置指征的慢快综合征患者房颤发作时置入心房电极的方法、术中术后心房电极的参数进行分析。结果:所有病例全部成功置入心房电极。4例阵发性心房扑动(房扑)患者经超速刺激转复2例;普罗帕酮转复8例阵发性房颤、房扑患者4例成功,胺碘酮转复14例阵发性房颤患者6例成功,总转复率45%。12例术后复律后程控测得P波振幅、心房电极阻抗、起搏阈值与12例术中复律患者测得的参数差异无统计学意义(P>0.05);10例房颤患者术中测得心房波为(0.8±0.6)mV,明显小于术后复律后程控测得的P波(1.4±0.5)mV(P<0.05),但两者阻抗无明显差别(P>0.05)。结论:心脏起搏器置入术中房颤发作时置入心房电极安全可靠。     

起搏器置入术后并发房颤的危险因素研究进展

房颤(AF)是临床上最常见的心律失常之一。起搏器置入术后房颤的发生率高于普通人群,其中年龄、高血压、左心房扩大、窦房结综合征(SSS)、起搏模式、心房及心室起搏比例、起搏器置入方式等均是影响起搏器置入术后新发房颤的危险因素。本文针对上述因素影响房颤发生的机制作一综述,以期为临床提早预防房颤提供理论参考。     

有预防心房颤动程序的双腔频率应答型起搏器的抗心房颤动作用

目的：观察具有预防心房颤动程序的DDDR型起搏器（Vitatron 900E)预防阵发性心房颤动的机制及效果。方法：对10例阵发性心房颤动分3段（每段2周），第1段启动起搏器进入房性心律失常记录状态，DDD60次／min，探查心房颤动的诱发因素；第2段为起搏治疗段1，DDD85次／min，观察超速起搏的抗心房颤动作用；第3段为起搏治疗阶段Ⅱ，DDD70次／min，据第1阶段获悉的心房颤动的触发因素，启动4个预防心房颤动程序中相关的项目。结果：10例均可控制心房颤动，3例用心房超速起搏控制，7例仅通过启动“房性期前收缩后反应”及／或运动后心率控制程序，其中3例尚需用可达龙0．2g/天。结论：抗心房颤动起搏器有防治阵发性心房颤动作用，尤其适用于合并病态窦房结综合征的患者。     

Does treatment with ACE inhibitors or angiotensin II receptor antagonists prevent atrial fibrillation after dual chamber pacemaker implantation?

AIMS: A retrospective observational study was performed to test the hypothesis that a lower incidence of atrial fibrillation (AF) would be observed in patients treated with either angiotensin converting enzyme (ACE) inhibitors or angiotensin II receptor antagonists (AIIRAs) than those without these drugs, 1-year following implantation of a dual chamber pacemaker for all indications. METHODS: One hundred and sixty consecutive patients who underwent implantation of a dual chamber pacemaker between January and August 2002 were identified and their case notes were retrospectively analysed. The primary endpoint was the presence of persistent AF (confirmed by 12-lead ECG recorded from the visit to the pacemaker clinic) at 12-month follow-up. RESULTS: Overall, 8% patients developed new onset persistent AF at 1-year follow-up. The incidence of AF at 1-year was 4% in patients treated with ACE inhibitors, 8% in patients taking AIIRAs or 5% on either drug. Although a trend towards a higher incidence of AF was observed at 1-year (10%) in patients not receiving either of these drugs, this was not statistically significant (P = 0.21, drug vs. no drug). The incidence of AF in patients with a previous history of paroxysmal AF or cardioversion was significantly higher (23%) than those patients without (5%), P < 0.0001. An odds ratio (95% CI) of 7.9 (2.3-27.8) was obtained. CONCLUSION: To confirm these interesting initial results and to investigate this important relationship further, larger prospective randomised controlled studies are required.     

Newly detected atrial fibrillation following dual chamber pacemaker implantation

Introduction: Pacemaker (PPM)-detected atrial high-rate episodes (AHREs) of even 5-minute duration may identify patients at increased risk for stroke and death. In this study, we sought to determine the incidence of newly detected atrial fibrillation (AF defined as an AHRE ≥5 minutes) in patients following dual-chamber PPM implantation and to define the clinical predictors of developing AF.
Methods and Results: We evaluated 262 patients (142 male; age 74 ± 12 years) without documented AF who underwent PPM implantation for sinus node dysfunction (n = 122) or atrioventricular block (n = 140). Information regarding patient demographics, cardiovascular diseases, and medication history was obtained. The cumulative percentages of ventricular pacing as well as the frequency, duration, and time to first episode of an AHRE were also determined. During follow-up of 596 ± 344 days, an AHRE ≥5 minutes was detected in 77 (29%) patients. Of these, 47 (61%) patients had an AHRE ≥1 hour, 22 (29%) patients had an AHRE ≥1 day, and 12 (16%) patients had an AHRE ≥1 week. An AHRE ≥5 minutes was seen in 24% and 34% of patients at 1 year and 2 years, respectively. Among patients with sinus node dysfunction, ≥50% cumulative ventricular pacing was the only significant predictor of an AHRE ≥5 minutes (HR 2.2; CI 1.0–4.7; P = 0.04).
Conclusions: Within 1 year of PPM implantation, AF is detected in 24% of patients without history of AF. In patients with sinus node dysfunction, ≥50% cumulative right ventricular pacing is associated with a 2-fold increase in risk of developing AF.     

植入起搏器的阵发性心房颤动患者导管消融术后临床分析

目的 对导管消融治疗阵发性心房颤动(房颤)合并窦房结功能障碍植入永久起搏器治疗的患者进行分析,比较传统心电图记录判断房颤复发率与起搏器程控记录模式转换事件判断房颤复发率有无差别.方法 所有患者因阵发性房颤接受导管消融治疗,因合并病态窦房结综合征于导管消融前后植入双腔起搏器治疗.消融术后3个月随访开始记录房颤发作情况.分别通过传统记录方式(心电图、24 h动态心电图)和起搏器程控记录(模式转换事件)判断房颤复发情况.结果 共40例(男28例)患者纳入研究,平均年龄(46.00±9.37)岁,左心室射血分数0.52 ～0.73 (0.61±0.03),左心房内径31.00 ～38.00(34.00±6.56)mm,随访4.5～42.0(25.0±8.2)个月.随访结束时,38例患者维持窦性心律.根据临床症状、心电图、24 h动态心电图诊断房颤复发10例(25％);根据起搏器程控记录房颤复发16例(40％).结论 合并病态窦房结综合征的阵发性房颤患者,需要植入永久起搏器.导管消融术后根据心电图和起搏器腔内电图判断房颤的复发率有无差别.     

不同部位心房起搏对植入双腔起搏器患者术后发生心房颤动的影响

目的]研究高位房间隔起搏(HASP)和右心耳起搏(RAAP)对心房电活动及心房结构的影响,评估HASP的安全性及临床有效性。[方法]回顾分析2013年1月—2017年1月于哈尔滨医科大学附属第二医院心内科行双腔起搏器植入的病态窦房结综合征患者142例,根据患者心房起搏电极植入的部位分为两组:HASP组100例,RAAP组42例。分别记录术前和术后P波时限、P波离散度、左心房大小及心房电极起搏参数(起搏阈值、感知、阻抗),并进行回顾性分析和对比研究。[结果]入选的142例患者的性别、年龄、既往疾病、吸烟饮酒史等因素无明显差异。RAAP组术前P波时限为(128.03±17.11) ms,术后为(144.82±21.37) ms;HASP组术前P波时限为(125.48±13.20) ms,术后为(102.08±15.23) ms;两组术后P波时限相比有统计学差异(P＜0.001)。RAAP组术前P波离散度为(27.33±10.12) ms,术后为(18.64±6.59) ms;HASP组术前P波离散度为(27.12±8.58)ms,术后为(18.89±4.85)ms;两组间P波离散度虽无明显差异(P＝0.47),但两组P波离散度术后较术前均减小。RAAP组与HASP组左心房内径无明显差异(34.07±5.71比32.48±4.19,P＝0.10)。HASP组起搏参数稳定,无额外并发症。植入起搏器1年后程控随访时发现,RAAP组患者发生心房颤动的比例为16.7%,而HASP组仅为4.0%,两组间有统计学差异(P＝0.015)。程控随访2年,RAAP组患者发生心房颤动的比例为28.6%,HASP组为17.0%,两组间无统计学差异。[结论]HASP是一种安全可行的起搏方式,可以明显缩短P波时限,有机会减少患者发生心房颤动的风险。     

Paradoxical atrial undersensing due to inappropriate atrial noise reversion of atrial fibrillation in dual-chamber pacemakers

Paradoxical atrial undersensing. BACKGROUND: Paradoxical atrial undersensing at high atrial sensing levels was described as false atrial noise reversion of dual-chamber pacemakers during atrial fibrillation in a sheep model. It is unknown whether this phenomenon occurs in humans. METHODS: In total, 71 patients with implanted dual-chamber pacemakers and atrial fibrillation were tested for the occurrence of paradoxical atrial undersensing. After determination of the sensing threshold of atrial fibrillation (30 seconds of continuous mode switch), the atrial sensing level was stepwise increased. If, after correct mode switch behavior at insensitive levels, loss of mode switch occurred at higher sensing levels and if the pacing mode was consistent with atrial noise reversion, paradoxical atrial undersensing was assumed. RESULTS: Paradoxical atrial undersensing could be provoked in 9 of 71 (13%) patients at a median sensing level of 0.4 (range 0.15-2.0) mV. Six different pacemaker models of five different manufacturers were affected. The occurrence of paradoxical atrial undersensing was significantly associated with the sensing threshold of atrial fibrillation (2.7+/-1.5 mV for patients with paradoxical undersensing compared to 1.6+/-1.3 mV for those without, P=0.02). Decreasing the atrial sensing level avoided paradoxical undersensing in 8 of 9 patients while maintaining an adequate safety margin for the detection of atrial fibrillation. CONCLUSION: Paradoxical atrial undersensing is inherent to all current dual-chamber pacemakers. The incidence is about 13% when using very high atrial sensing levels. Inappropriate atrial noise reversion can be resolved in most of the cases by decreasing atrial sensing levels and knowledge of this phenomenon is important to avoid unwarranted atrial lead revisions.     

Effect of Atrial Tachyarrhythmia Duration on Percentage of Time with Atrial Pacing in Pacemaker Patients with Paroxysmal Atrial Fibrillation

Atrial pacing can prevent the recurrence of paroxysmal atrial tachyarrhythmia (AT) in pacemaker patients. The aim of the study was to determine in pacemaker patients the effect of AT duration on the percentage of time with atrial pacing by programming the same setting twice. METHODS: In 14 pacemaker patients with paroxysmal AT the dual-chamber pacemaker was programmed to identical parameters for two consecutive follow-up periods. The pacemakers were interrogated after three months to determine the percentage of time with atrial pacing relative to the total time of follow-up periods and the AT duration (atrial rates >150 bpm). The two three-month follow-up periods were compared to each other. The differences between the two follow-up periods were determined for the percentage of time with atrial pacing as well as for the AT duration. To assess the relationship between atrial pacing and AT duration, the differences between the two follow-up periods for atrial pacing and AT duration were correlated to each other. In addition, the percentage of atrial pacing was corrected for AT duration. RESULTS: Median percentage of atrial pacing relative to the complete follow-up period was 73% after the first and 76% after the second period and median AT duration 21% and 18%, respectively (not significantly different). The differences between the first and second study period were 1% for atrial pacing and -2% for AT duration. The percentage of atrial pacing and AT duration were inversely related together with a significant correlation coefficient of r = 0.95 ( p = 0.0001). After atrial pacing was corrected for AT duration, the percentage of atrial pacing relative to the time in sinus rhythm was significantly higher with a median of 93% for the first and second period ( p = 0.005). The correlation coefficient between the percentage of atrial pacing relative to the time in sinus rhythm and AT duration was r = 0.08 (not significant). CONCLUSIONS: The percentage of time with atrial pacing can be underestimated in patients with paroxysmal atrial fibrillation and should be carefully interpreted in relation to AT duration.     

Temporal patterns of paroxysmal atrial fibrillation following DDDR pacemaker implantation

Paroxysmal atrial fibrillation (AF) episodes have been reported to be randomly distributed. However, because patients are not always symptomatic, it has been difficult to study temporal patterns of AF. Newer implantable pulse generators have data-logging capabilities that permit the detection and analysis of temporal patterns of AF. This study tested the hypothesis that AF episodes occur in clusters over time and that these episodes are not randomly distributed in individual patients. The date and time of 582 episodes of AF were recorded from the data logs of 16 patients with a Medtronic Thera DR followed 6 weeks and 6 and 12 months after pulse generator implant. The probability of AF recurrence and the interevent intervals between successive episodes of AF were fitted to monoexponential and Weibull distributions. A Weibull distribution best described the nonrandom distribution of AF for 67% of follow-up visits. Temporal clustering of AF (interevent intervals <24 hours) declined during follow-up (95 ± 10%, 90 ± 11%, and 74 ± 28% at the 6-week and 6- and 12-month visits, respectively; p <0.05). The average duration of an episode of AF tended to increase over time (0.31 hour, 95% confidence intervals [CI] 0.17 to 0.58 hours; 0.36 hours, 95% CI 0.17 to 0.78 hours; 0.65 hours, 95% CI 0.29 to 1.45 hours [p = 0.07] at the 6-week and 6- and 12-month visits, respectively). Paroxysmal AF recurrence is nonrandomly distributed over the long term in many patients. The temporal patterns of AF change over time after pacemaker implantation. This has implications for the selection of study end points in AF clinical trials.     

Ventricular fibrillation complicating pacemaker insertion in acute myocardial infarction

Temporary transvenous pacing catheters were placed in 101 patients with acute myocardial infarction (Ml) for the management of bradyarrhythmias or conduction disturbances. Fourteen (14%) patients (group A) developed ventricular fibrillation (VF) at the time of pacing catheter manipulation in the right ventricle. Compared to the remaining 87 (86%) patients (group B), the patients in group A were younger (56.1 vs 65.8 yrs, P = 0.007). Thirteen (92.8%) of 14 patients in group A had inferior MI compared to 58 (66.6%) of 87 patients in group B (P = 0.04). All but one patient in group A had pacemaker insertion within 24 h of the onset of symptoms of Ml compared to 55 (63%) of 87 in group B (P = 0.02). In 12 of the 14 patients in group A, following defibrillation and intravenous bolus administration of lidocaine, the pacing catheter was positioned in the right ventricle without further episodes of VF. It is concluded that (1) in patients with acute MI temporary transvenous pacemaker insertion may be complicated by VF; (2) VF is most likely to occur in younger patients with inferior MI infarction when the pacing catheter is inserted within 24 h of the onset of symptoms of infarction; and (3) administration of an intravenous bolus of lidocaine may be effective in preventing the induction of VF by catheter manipulation.     

Atrial fibrillation after cardiac surgery: Prevention and management: The Australasian experience

Background

Atrial fibrillation (AF) after cardiac surgery is a major health problem that is associated with a significant financial burden. This paper aims to highlight this problem and review the current guidelines in the prevention and management of AF after cardiac surgery, providing our experience in the Australasian centers.

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。     

Incidence of arrhythmias after atrial or dual-chamber pacemaker implantation

The incidence of sustained atrial, pacemaker-mediated and ventricularrhythm disturbances was studied retrospectively in a consecutiveseries of112 patients without a history of preexisting atrialtachy arrhythmias, receiving an atrial or dual-chamber pacemaker. Early atrial fibrillation (during the first week) was recordedtwice. Late atrial fibrillation was seen in seven patients,flutter in one, yielding a total incidence of 8.9% for 22 months.There were no significant differences with respect to age, aetiology,electrocardiographic diagnosis, pacing history, or the measuredintracardiac P wave between the group with and the group withoutatrial fibrillation. Treatment with digoxin reverted three patientsto sinus rhythm, association of digoxin and amiodarone, sixpatients. One patient with congestive heart failure remainedin atrial fibrillation. Pacemaker-mediated tachycardia was not a major problem. Onepatient of a subgroup with known ventricular arrhythmia hada non-sustained ventricular tachycardia during programming atfollow-up; sustained ventricular tachycardia was not recorded.Reprogramming to VDD, DVI or VVI was done in 6/100patients. The incidence of atrial fibrillation or flutter in highly selectedpatients with dual-chamber or atrial pacing is moderately low.It is not possible to identify patients with a high risk fordevelopment of atrial fibrillation; when it occurs, it is easilycontrolled with drugs. DDD pacing seems to be safe in patients with a history of seriousventricular arrhythmias, treated with appropriate drugs.     

Atrial natriuretic peptide in atrial fibrillation before and after electrical cardioversion therapy

In eight patients with atrial fibrillation of less than 3 monthsduration and without congestive heart failure the plasma concentrationof atrial natriuretic peptide was determined one day before,the day after and again 30 days after electrical cardioversiontherapy. The pretreatment plasma concentration of the peptidewas 99 pg mg^–1 (23–480, median and range). The dayafter cardioversion to sinus rhythm the peptide concentrationhad normalized to 36 pg ml^–1 (18–151). The plasmaconcentration of atrial natriuretic peptide remained stablein all but one patient for a period of 30 days (46 pg ml^–1,16–695) (P = 0·03). In conclusion, the plasma concentration of atrial natriureticpeptide in patients with atrial fibrillation was significantlyreduced after electrical cardioversion to sinus rhythm and remainedstable for a period of 30 days.     

Left atrial pacemaker dominance after catheter ablation of atrial fibrillation

We report a case of left atrial dominant rhythm demonstrated by electroanatomic mapping. The rhythm occurred after radiofrequency catheter ablation in a patient with persistent atrial fibrillation and structural heart disease.     

起搏器安置术后心房颤动发生情况的远期随访

目的研究首次接受起搏治疗的患者心房颤动(简称房颤)发生情况及预后影响因素。方法回顾性分析本院2003年至2008年初次安置永久起搏装置窦性心律患者的临床和随访资料,统计术后房颤的发生情况,单因素分析筛选出房颤发生的危险因素,以Cox风险比例模型筛选房颤发生的独立预后因素。结果共入选1 344例,经过(75.7±24.5)个月的随访患者房颤发生率21.1%,其中持续房颤发生率10.8%。经Cox风险模型筛选出与房颤发作关系最为密切的5个因素:既往有阵发房颤病史、病因为病窦综合征、肺动脉压力高于正常、年龄≥65岁、VVI起搏模式,其风险比分别为3.43、1.86、1.65、1.4、1.3,经Kaplan-Meier方法分析,前述因素在随访中位数77个月时分别增加房颤风险31%、15.9%、6.1%、4.8%、5.5%。结论房颤在老年、VVI起搏、病窦综合征、阵发房颤病史、肺动脉压力增高的患者中发生比例高。