Effects of atrial septal defects on the cardiac conduction system

The case report presented in this edition by Mu et al.The report presents a case of atrial septal defect(ASD)associated with electrocardiographic changes,noting that the crochetage sign resolved after Selective His Bundle Pacing(S-HBP)without requiring surgical closure.The mechanisms behind the appearance and resolution of the crochetage sign remain unclear.The authors observed the dis-appearance of the crochetage sign post-S-HBP,suggesting a possible correlation between these specific R waves and the cardiac conduction system.This editorial aims to explore various types of ASD and their relationship with the cardiac con-duction system,highlighting the diagnostic significance of the crochetage sign in ASD.

Left bundle branch pacing set to outshine biventricular pacing for cardiac resynchronization therapy?

The deleterious effects of long-term right ventricular pacing necessitated the search for alternative pacing sites which could prevent or alleviate pacinginduced cardiomyopathy.Until recently,biventricular pacing(BiVP)was the only modality which could mitigate or prevent pacing induced dysfunction.Further,BiVP could resynchronize the baseline electromechanical dssynchrony in heart failure and improve outcomes.However,the high non-response rate of around 20%-30%remains a major limitation.This non-response has been largely attributable to the direct non-physiological stimulation of the left ventricular myocardium bypassing the conduction system.To overcome this limitation,the concept of conduction system pacing(CSP)came up.Despite initial success of the first CSP via His bundle pacing(HBP),certain drawbacks including lead instability and dislodgements,steep learning curve and rapid battery depletion on many occasions prevented its widespread use for cardiac resynchronization therapy(CRT).Subsequently,CSP via left bundle branch-area pacing(LBBP)was developed in 2018,which over the last few years has shown efficacy comparable to BiVP-CRT in small observational studies.Further,its safety has also been well established and is largely free of the pitfalls of the HBP-CRT.In the recent metanalysis by Yasmin et al,comprising of 6 studies with 389 participants,LBBPCRT was superior to BiVP-CRT in terms of QRS duration,left ventricular ejection fraction,cardiac chamber dimensions,lead thresholds,and functional status amongst heart failure patients with left bundle branch block.However,there are important limitations of the study including the small overall numbers,inclusion of only a single small randomized controlled trial(RCT)and a small follow-up duration.Further,the entire study population analyzed was from China which makes generalizability a concern.Despite the concerns,the meta-analysis adds to the growing body of evidence demonstrating the efficacy of LBBP-CRT.At this stage,one must acknowledge that the fact that still our opinions on this technique are largely based on observational data and there is a dire need for larger RCTs to ascertain the position of LBBPCRT in management of heart failure patients with left bundle branch block.

Dual-chamber pacing confers better myocardial performance and improves clinical outcomes compared to single-chamber pacing

The deleterious effects of long term right ventricular pacing are increasingly being recognized today.Current clinical practice favors the implantation of dual-chamber permanent pacemaker which maintains atrioventricular synchrony and is associated with better quality of life.However,despite the popular belief and common sense surrounding the superiority of dual-chamber pacing over single chamber pacing,the same has never been conclusively verified in clinical trials.Some observational evidence however,does exists which supports the improved cardiac hemodynamics,lower the rate of atrial fibrillation,heart failure and stroke in dual-chamber pacing compared to single-chamber pacing.In the index study by Haque et al,right ventricular pacing,particularly in ventricular paced,ven-tricular sensed,inhibited response and rate responsive pacemaker adversely im-pacted the left ventricular functions over 9-months compared to dual pacing,dual sensing,dual responsive and rate responsive pacemaker.Although there are key limitations of this study,these findings does support a growing body of evidence reinstating the superiority of dual chamber pacing compared to single chamber pacing.

Comparison of His-purkinje bundle pacing and right ventricular inflow tract septal pacing in the elderly

Objective To compare the short-term clinical effect and electrical parameters of His-purkinje bundle pacing(HPBP) and right ventricular inflow tract septal pacing(RVIP) in the elderly. Methods Between April 2017 and September 2019, sixty patients with indications for permanent cardiac pacing and resynchronization therapy in Beijing Anzhen Hospital were divided into the HPBP and RVIP groups, and were analyzed. A ventricular pacing lead was implanted in left ventricular septal sites with left bundle potentials or His potentials in the HPBP group. The lead was placed in right ventricular inflow tract septal sites close to distal His-bundle regions without potentials from the His-purkinje conduction system in the RVIP group. Lead impedance, R wave amplitude, pacing thresholds, QRS duration, left ventricular ejection fraction(LVEF), and left ventricular end-diastolic diameter(LVEDD), mitral regurgitation area reflux, QTc, T wave directivity, Tp-e and Tp-e/QT ratio were compared between the HPBP and RVIP groups during the procedure and the short-month follow-up. Results No significant differences were found in lead impedance, R wave amplitude, QRS duration, LVEF, LVEDD, mitral regurgitation area reflux, QTc, T wave directivity, Tp-e and Tp-e/QT ratio between the HPBP and RVIP groups. However, the pacing threshold was significantly lower in the HPBP group than in the RVIP group(0.7 ± 0.2 vs. 0.9 ± 0.3 V, P = 0.02). Conclusions The efficacy and electrical parameters of HPBP is comparable with RVIP during the procedure and the short-term follow-up.

希浦系统起搏对老年起搏诱导性心肌病病人效果的Meta分析

目的评估右心室起搏后,患起搏诱导性心肌病的老年病人升级至希浦系统起搏的临床疗效和安全性。方法在PubMed、Cochrane Library、Web of Science、Embase、中国知网、万方数据库、维普数据库检索希浦系统起搏对起搏诱导性心肌病疗效的相关文献,提取研究中有关临床获益和安全性的数据,在RevMan 5.4软件上进行Meta分析。结果共纳入8篇文献,包括185例病人,升级希浦系统起搏的成功率为95%。Meta分析结果显示:升级希浦系统起搏后,随访期间病人的左心室射血分数(MD=-11.73,95%CI:-14.74~-8.72,P<0.01)较升级术前提高,QRS波时限(MD=59.84,95%CI:55.98~63.70,P<0.01)较升级术前缩短,NYHA心功能分级(MD=1.05,95%CI:0.70~1.41,P<0.01)较升级术前明显降低,差异均有统计学意义。起搏阈值(MD=-0.11,95%CI:-0.24~0.02,P=0.08)和R波振幅(MD=-0.35,95%CI:-1.94~1.24,P=0.66)升级术前后差异无统计学意义。同时研究中观察到2例病人死亡。结论对于老年起搏诱导性心肌病病人,可考虑升级起搏方式为希浦系统起搏,不仅可以纠正长期右心室起搏引起的心脏电不同步和心室重塑,同时也能改善病人的临床心功能并减少手术相关并发症。

双腔起搏器“A PACE ON PVC”功能的相关心电图改变

"PVC OPTIONS"功能是双腔起搏器对室性早搏反应的特殊功能。该功能设置有两种反应方式:"+PVARP ON PVC"和"A PACE ON PVC"。通常具有这项特殊功能的起搏器,其默认设置是两项功能同时开启。"A PACE ON PVC"功能的特点是心房提前起搏,可能会被误诊为起搏功能异常。本文将着重阐述该功能的相关心电图改变。

A case of recurrent PMT caused by poor atrial pacing

Pacemaker mediated tachycardia(PMT)can occur in patients with DDD pacemaker implantation,and PMT in narrow sense is a kind of circular motor tachycardia,which is often caused by ventricular atrial retrograde conduction.This paper reports a case of patients with high atrial pacing value in the early stage of pacemaker implantation,resulting in atrial retrograde conduction and recurrent PMT,Almost non-stop.Although the pacemaker has the PMT automatic termination procedure,PMT is still a short array of repeated attacks due to the presence of poor atrial pacing,resulting in the patients with shortness of breath,lower extremity edema and other heart failure symptoms.Finally,PMT was stopped by prolonging PVARP,and its lower starting frequency was slowed down to 50bpm,and AV interval was kept unchanged for 250ms,so as to reduce the release of atrial pulse and encourage the emergence of self selling down-propagation excitation.The proportion of atrial and ventricular pacing was significantly reduced,which not only saved the electric energy of pacemaker,but also conformed to the physiology.In a narrow sense,pacemaker mediated tachycardia(PMT)is a kind of circular motor tachycardia,which is often caused by reverse ventricular conduction.Repeated attacks for a long time may affect the patient's heart function.Although most modern pacemakers have PMT automatic termination procedures,they are still relatively passive in the presence of some induced factors.Finally,it is necessary to extend PVARP to truly terminate and prevent PM.A case of recurrent PMT due to poor atrial pacing is reported.

The pacing treatment of atrial fibrillation

The incidence of atrial fibrillation(Af)is on the first position in arThythmia and thetreatment is very difficuit The method of non-drug to prevent Af has been extensively paidattention to of late years.It is a relatively new idea to treat Af by means of pacing.In thispaper,we made a research to the Af’s pacing treatment in 3 different conditions.The resultshowed that this method of pacing treatment Afis feaslble.In a long follow-up survey,we divided the patients into 3 groups:(1) group VVI:76 casesin all,in which 40 cases of male and 36 cases of female.All the pacemakers are unicameralVVI.(2) group AAI:46 cases in all,in which 30 cases of male and 16 cases of female.Allthe pacemakers are unicameral AAI.(3) group DDD:25 cases in all.in which 15 cases ofnude and 10 cases of female.All the pacemakers are double cameral DDD.We made afollow-up survey every 3 or 6 months after the pacemaker implantation and examined theclectrocardiogram(ECG).tested and carried out program control to the pacemaker.Theresults showed that the recunence rate of Af in VVI group is 41%,in AAI group is 4%,inDDD group is 5% This result is similar to the reports concemed overseas.It means that thepacing position had remarkable influence to the Af.In addition,the pacing treatment of Af also has some relationship pacing frequency.Itwas found in the follow-up study that the higher the frequency is,the lower the Af’srecurrence rate be comes,The reason may be that the atrium’s vulncrable period is shortedwith the pacing frequency increasing and finally prevent Afs taking place.The primary factors that influence Af are as follows:(1)the size of atrium,(2) theexistence of structural conduction and the existence of dispersive refractory period.(3)thepulse’s wave length.In a word,we think that different pacing position can influence Af’s happening,and thepacing with high frequency also has a definite effect to prevent At’s recurrence.

心脏起搏导线植入位点的优化更新

心脏起搏是治疗有症状性心动过缓的有效方法。长期、高比例的右室心尖部起搏使患者发生心力衰竭、心房颤动的风险增加。传统双心室起搏通过右室心内膜和左室心外膜双心室同步起搏,并非是生理性的起搏,且无应答率较高。心脏传导系统起搏是一种利用心脏传导系统激动心室的生理性起搏,包括希氏束起搏和左束支区域起搏。与右心室起搏/双心室起搏相比,心脏传导系统起搏具有更好的心室电和机械同步性。同希氏束起搏相比,左束支区域起搏具有更佳的起搏参数(起搏阈值更低且平稳、较高的R波振幅)。通过阐述心脏起搏导线植入位点从右心室心尖部起搏到右心室间隔/流出道起搏,再到心脏传导系统起搏的优化更新,介绍各种起搏方式并比较不同起搏方式的优缺点,突显出生理性起搏的优势,并对生理性起搏的未来前景进行展望。

Recent approaches to His-Purkinje system pacing

Objective:Physiologic cardiac pacing is a novel technique which has been largely popularized in recent decades.His bundle pacing (HBP) has been long considered the most physiologic pacing method;however, with the widespread implementation of this method, its disadvantages have become apparent.In this context, left bundle branch pacing (LBBP)-directly engaged in the His-Purkinje system-has been foreseen as the best pacing method to mimic physiologic activation patterns.This review aimed to summarize recent approaches to physiologic cardiac pacing.Data sources:This review included fully peer reviewed publications up to July 2018, found in the PubMed database using the keywords "His bundle branch pacing," "right ventricular pacing," and "physiologic pacing." Study selection:All selected articles were in English, with no restriction on study design.Results:The HBP has been studied worldwide, and is currently considered the most physiologic pacing method.However, it has disadvantages, such as high pacing threshold, unsatisfactory sensing and long procedure times, among others.Although LBBP is theoretically superior to HBP, the clinical relevance of this difference remains under debate, as few large randomized clinical trials with LBBP have been published.Conclusions:Although HBP indeed appears to be the most physiologic pacing method, it has certain shortcomings, such as high pacing threshold, difficult implantation due to specific anatomic features, and others.Further studies are required to clarify the clinical significance of LBBP.

左束支区域起搏临床应用研究进展

传统的右心室起搏引起电-机械不同步导致或加重心房颤动、心力衰竭等的风险。双心室起搏可改善心室不同步,但也无法消除电不同步,同时有较高的无应答率。希氏束起搏是一种理想的生理性起搏模式,但其起搏阈值较高且手术难度较大等限制其在临床的应用。左束支区域起搏由于起搏阈值低且手术难度较低被认为是克服希氏束起搏局限性的有效替代方法。本文将从左束支起搏操作及夺获标准、左束支起搏并发症及临床应用等方面对已发表的文献进行综述。

不同阻滞位置房室传导阻滞患者左束支区域起搏的可行性探讨

目的探讨不同阻滞位置的房室传导阻滞患者行左束支区域起搏的可行性。方法32例因房室传导阻滞住院行起搏器植入患者,行心脏电生理检查,房室结阻滞11例、希蒲传导系统阻滞21例;根据心室电极植入位置分为两组,18例为右心室间隔部起搏(RVSP组),14例为左束支区域起搏(LBBaP组),比较两组术后QRS宽度、心室电极感知、心室起搏阈值、心室电极阻抗、手术时间和X线曝光时间。结果14例患者成功行LBBaP,成功率93.3%(14/15)。LBBaP组术后QRS波群宽度较RVSP组明显缩短,存在明显统计学差异[(133.18±16.90)ms vs.(106.36±15.18)ms,P<0.001]。两组在电极感知、起搏阈值及电极阻抗方面无统计学差异;但是LBBaP组手术时间及X线曝光时间明显长于RVSP组,且存在明显统计学差异(P<0.01)。房室结阻滞患者和希蒲传导系统阻滞患者行左束支区域起搏术后QRS波群宽度明显缩短,但二者间无统计学差异[(106.00±7.58)ms vs.(108.90±5.34)ms,P=0.757]。在LBBaP组中有8例合并左束支或右束支传导阻滞,7例束支阻滞得到校正,其中5例为完全性右束支阻滞,给予双极起搏,术后QRS波宽度明显变窄。结论左束支区域起搏对于房室结阻滞和希蒲系传导系统阻滞导致的房室传导阻滞患者有较高成功率,即刻效果及安全性良好,起搏参数稳定;相对于右心室间隔部起搏,左束支区域起搏可明显缩短QRS波宽度、保持心室同步性,尤其对于合并束支传导阻滞的患者。

双心室起搏治疗充血性心力衰竭的临床疗效

目的 :观察双室起搏治疗充血性心力衰竭 (CHF)的血流动力学及临床效果。方法 :CHF伴室内传导阻滞患者11例均植入双室起搏器 ,左室电极导线经冠状静脉窦插入抵达侧或后侧静脉 ,以达到左室起搏夺获。手术前、后应用 Swan- Ganz漂浮导管及超声心动图检查 ,观察双室起搏的血流动力学及临床效果。结果 :所有病例植入双心室起搏后临床症状改善 ,活动耐量增加。心输出量、心脏指数、射血分数均较术前明显改善。肺毛细血管嵌顿压下降 ,二尖瓣返流面积减少 ,治疗 3月后左心室舒张末期直径由 75± 8m m下降至 6 8± 6 m m(P<0 .0 5 )。结论 :双心室起搏治疗 CHF伴心室内传导阻滞患者 ,可明显缓解临床症状 ,逆转左心室重塑 ,改善心功能。

食道调搏在儿科房室交界区功能检查中的应用

目的 探讨食道心房调搏测量儿童房室交界区各不应期和传导时间的应用价值 ,评价其传导功能及其特点。方法 对 5 9例正常儿童进行食道调搏 (TEAP)检查 ,测量房室交界区不应期和传导阻滞点。结果 正常儿童房室传导功能由不应期和传导阻滞点具体体现 ,为儿童正常值提供参考 ;相对不应期 (RRP)、功能不应期 (FRP)、文氏点与心率呈显著相关 (P分别为 0 .0 0 0、0 .0 1、0 .0 0 0 ) ,与性别、年龄无关 (P均 >0 .0 5 ) ;而绝对不应期 (ERP)、2∶1阻滞点与性别、年龄、心率均无关 (P均 >0 .0 5 ) ;文氏点与RRP显著相关 (P =0 .0 0 0 ) ;2 :1阻滞点与ERP显著相关 (P =0 .0 15 )。结论 TEAP可评估儿童房室交界区的传导功能 ;RRP与心率有直接关系 。

双心室起搏治疗慢性心力衰竭伴心室内传导阻滞患者的近期疗效

目的观察双心室起搏治疗慢性心力衰竭（心衰）的临床效果。方法慢性心衰患者13例均伴心室内传导阻滞，体表心电图QRS波时限为146±9ms，心功能（NYHA）Ⅲ～Ⅳ级，超声心动图显示左心室射血分数（LVEF）为0．28±0．06，左心室舒张末径（LVEDD）为68±5mm。患者植入三腔起搏器行心房感知，双心室起搏。结果术后体表心电图QRS波时限缩短至122±7ms（P〈0．01），心功能平均提高1级。术后1月超声心动图显示LVEF增至0．36±0．06（P〈0．05），舒张期充盈改善，二尖瓣返流减少。结论双心室起搏可有效改善慢性心衰伴心室内传导阻滞患者近期的心功能。

心室起搏发生室房传导与返复心律的临床分析

随访２３例心室起搏后出现室房传导者，其Ｓ－Ｐ（Ｓｐｉｋｅ－Ｐｗａｖｅ）时间为２６７±１３０（１６０～６４０）ｍｓ。其中１５例心电图仅呈现逆行传导的Ｐ（Ｐ）波，８例同时出现返复心律；１１例临床上有不同程度的起搏器综合征表现。有与无起搏器综合征者Ｓ－Ｐ时间比较无明显差异（２０３．３±２９．０ｍｓｖｓ１９０．０±２６．２ｍｓ，Ｐ＞０．０５）。临床症状与返复心律出现的频率及Ｓ－Ｐ时间有关。本组６例起搏器综合征患者血液动力学结果：①右房压升高。②股动脉压持续降低（＞２．７ｋＰａ）。③动脉压呈波动性下降。④有返复心律时室压波动。这四种情况可以单独出现或并存。血液动力学变化与逆传激动激活房壁及肺静脉壁压力感受器反射性导致血压和颅内压下降。

双房同步起搏联合预防心房颤动的起搏治疗模式治疗快速房性心律失常的临床应用(附三例报告)

为观察三腔双房起搏联合预防心房颤动 (简称房颤 )的起搏治疗模式治疗快速性房性心律失常的临床效果。研究 3例房间传导阻滞合并快速性房性心律失常 ,并置入三腔双房同步起搏器的患者。起搏器具有房颤预防治疗功能。左房起搏通过冠状静脉窦置入 2 188电极导线 ,左右心房电极导线通过Y形转接器与双腔起搏器连接。DDTA起搏模式 ,随访 6个月 ,观察超驱动起搏、长间期抑制、房性早搏 (简称房早 )后加速起搏功能关闭和开启时 ,患者的临床症状、统计模式转换发生的次数、第一次至第二次房颤发作的间期、平均 2 4h房早记数。结果 :双房同步起搏后 ,患者快速房性心律失常的发作明显减少。超驱动起搏、长间期抑制、房早后加速起搏功能开启时 ,模式转换发生的次数减少、第一次至第二次房颤发作的间期延长、平均 2 4h房早记数明显减少。结论 :初步临床应用提示 :三腔双心房起搏联合预防房颤的起搏治疗模式治疗快速性房性心律失常可行且有效。

参松养心胶囊对快速心房起搏兔房颤电生理的影响

目的应用微电极阵(MEA)技术研究参松养心胶囊对快速心房起搏(RAP)兔房颤电生理的影响,探讨其抗房颤的作用机制。方法新西兰兔50只随机分成对照组、起搏组、起搏+参松养心胶囊A组(1 g/L)、起搏+参松养心胶囊B组(2 g/L)、起搏+参松养心胶囊C组(4 g/L)各10只。RAP 24 h后,迅速开胸取出心脏,行langendroff灌流,用柔性电极贴附右心房,分别记录各组场电位时限(fADP)、激动传导速度(ECV)和心率(HR)的变化。结果与对照组相比,起搏组兔心房肌fADP明显缩短,ECV明显减慢,HR明显加快(均P<0.05)。与起搏组相比,起搏+参松养心胶囊A、B、C组fADP明显延长、ECV明显加快、HR明显减慢(均P<0.05)。但参松养心胶囊A、B、C组HR变化无明显差异(P>0.05)。结论在RAP兔房颤中,参松养心胶囊通过对心肌细胞Na^(+)、K^(+)、Ca^(2+)等多离子通道的调节,发挥其抗房颤的作用。

心室起搏管理功能对房室传导阻滞患者的近期疗效观察

目的观察具备心室起搏管理（MVP）功能的起搏器（Adapta）在Ⅱ度或间隙性Ⅲ度房室传导阻滞患者的近期效果。方法29例患者入选，分别置入具有MVP功能的Adapt起搏器（实验组，n=17）和其他类型双腔起搏器（对照组，n=12）。并分别在置入前和置入后1、3个月进行随访。随访中观察上述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、左室舒张末内径、左室射血分数等变化。结果置入双腔起搏器（Adapta）术后1个月及3个月，与对照组比较，实验组心室起搏比例明显降低（39．89％±41．21％vs96．48％±3．52％；40．91％±43．49％vs94．53％±4．62％，P均〈0．05）。其他指标两组间无明显差异。结论起搏器心室起搏管理功能可以在短期内降低心室起搏比例。

心室起搏对后间隔旁道与快径逆传的诊断价值

通过右室心尖部和基底部两个不同部位的起搏，比较１５例房室结折返性心动过速（对照组）和８例隐匿性后间隔旁道参与的房室折返性心动过速患者（观察组）的室房传导时间（ＶＡＩ）。结果显示：①心尖部起搏时对照组ＶＡＩ为１７４±３４ｍｓ，与观察组１８６±３８ｍｓ相比无显著性差异（Ｐ＝ＮＳ）。②基底部起搏时观察组ＶＡＩ为１５３±２４ｍｓ，明显短于对照组１９９±３４ｍｓ，两者比较有显著性差异（Ｐ＜０．０１）。③两个部位（心尖部与基底部）ＶＡＩ的差值对照组≤０（－５０～０，平均－２４±１６ｍｓ）与观察组≥１５ｍｓ（１５～７５，平均３４±１９ｍｓ）比较有非常显著性差异（Ｐ＜０．００１）。提示右室心尖部与基底部连续起搏可快速。