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.

Analyses of risk factors and prognosis for new-onset atrial fibrillation in elderly patients after dual-chamber pacemaker implantation

Objective To retrospectively identify risk factors and the prognosis for new-onset atrial fibrillation (AF)after implantation of dual-chamber pacemakers in elderly patients.Methods Consecutive patients aged >65years who underwent their first implantation of a dual-chamber permanent pacemaker in Beijing Anzhen Hospital from October 2013to May 2016were enrolled.Their complete program- ming and follow-up data were recorded.Follow-up end points included new-onset AF and major adverse cardiovascular and cerebrovascular events.Restdts Altogether,322patients were enrolled,with new-onset AF observed in 79(24.5%)during their follow-up.Multivariable analysis identified four independent predictors of new-onset AF in elderly patients after pacemaker implantation:hypertension (HR =3.040, 95%CI:1.09-3.05,P =0.00),age (HR =1.966,95%CI:1.57-3.68,P =0.01);left atrial enlargement (HR =1.645,95%CI:1.05-1.25,P = 0.03);high ventricular pacing rate (HR =1.137,95%CI:1.01-1.06,P =0.01).Univariable analysis indicated that the CHA2DS2-VASc score was also a risk factor for AF (HR =1.368,95%CI:1.178-1.589,P =0.002),whereas multivariable regression analysis did not. Kaplan-Meier survival analysis showed that the risk for ischemic stroke was significantly higher in the new-onset AF group than in the non-AF group (P <0.05).Conclusion Hypertension,age,left atrial enlargement,and high ventricular pacing rate were independent predictors of new-onset AF in elderly patients after implantation of a permanent pacemaker.New-onset AF increased the risk for ischemic stroke.

Left bundle branch pacing vs biventricular pacing in heart failure patients with left bundle branch block:A systematic review and meta-analysis

BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore the validity of electromechanical resynchronization,clinical and echocardiographic response of LBBP-CRT.METHODS Systematic review and Meta-analysis were conducted in accordance with the standard guidelines as mentioned in detail in the methodology section.RESULTS In our analysis,the success rate of LBBP-CRT was determined to be 91.1%.LBBP CRT significantly shortened QRS duration,with significant improvement in echocardiographic parameters,including left ventricular ejection fraction,left ventricular end-diastolic diameter and left ventricular end-systolic diameter in comparison with BiVP-CRT.CONCLUSION A significant reduction in New York Heart Association class and B-type natriuretic peptide levels was also observed in the LBBP-CRT group vs BiVP-CRT group.Lastly,the LBBP-CRT cohort had a reduced pacing threshold at follow-up as compared to BiVP-CRT.

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.

Left bundle branch area pacing combined with implantable cardioverter-defibrillator treatment for heart failure after myocardial infarction

Left bundle branch area pacing(LBBAP)has emerged as a new physiological pacing mode.Previous studies have confirmed the feasibility and efficacy of LBBAP for cardiac resynchronization therapy(CRT)in heart failure(HF)patients with left bundle branch block(LBBB)and a narrower QRS duration(QRSd)to have a higher percentage of super responders,and lower pacing thresholds than biventricular pacing(BiVP).

Left bundle branch area pacing:A new era of cardiac resynchronization therapy?

The recent systematic review and meta-analysis provided a comprehensive focus on the current state of cardiac resynchronization therapy(CRT).The authors determined the feasibility of physiological left bundle branch area pacing(LBBAP)in patients indicated for CRT through a careful analysis of trials.They found that LBBAP was associated with significant reductions in QRS duration,New York Heart Association functional class,B-type natriuretic peptide levels,and pacing thresholds as well as improvements in echocardiographic parameters compared to biventricular pacing.

Management of a patient with an unusual trajectory of a temporary trans-venous pacing lead

Perforation of the right ventricle during placement of pacing wires is a welldocumented complication and can be potentially fatal.Use of temporary pacemaker,helical screw leads and steroids use prior to implant are recognised as risk factors for development of post-permanent pacemaker effusion.We reported an unusual case of pacing wire perforating interventricular septum into the left ventricle that occurred during the implant procedure performed in another institution.After the preoperative work-up and transfer to our tertiary cardiothoracic centre,the patient underwent successful surgical management.In conclusion,early recognition and timely diagnosis using advanced multimodality imaging can guide surgical intervention and prevent unfavourable consequences of device-related complications.

Selective his bundle pacing eliminates crochetage sign:A case report

BACKGROUND Crochetage sign is a specific electrocardiographic manifestation of ostium secundum atrial septal defects(ASDs),which is associated with the severity of the left-to-right shunt.Herein,we reported a case of selective his bundle pacing(SHBP)that eliminated crochetage sign in a patient with ostium secundum ASD.CASE SUMMARY A 77-year-old man was admitted with a 2-year history of chest tightness and shortness of breath.Transthoracic echocardiography revealed an ostium secundum ASD.Twelve-lead electrocardiogram revealed atrial fibrillation with a prolonged relative risk interval,incomplete right bundle branch block,and crochetage sign.The patient was diagnosed with an ostium secundum ASD,atrial fibrillation with a second-degree atrioventricular block,and heart failure.The patient was treated with selective his bundle pacemaker implantation.After the procedure,crochetage sign disappeared during his bundle pacing on the electrocardiogram.CONCLUSION S-HBP eliminated crochetage sign on electrocardiogram.Crochetage sign may be a manifestation of a conduction system disorder.

The Impact of Cardiac Pacing Site on Patient's Cardiac Function and Psychological State

With the widespread application of artificial permanent pacemakers in clinical practice,there have been new changes in the indications for pacemaker implantation.The current clinical indications include high atrioventricular block,sick sinus syndrome,cardiac resynchronization therapy for heart failure,and implantation of cardioverter defibrillators for ventricular arrhythmias.The implantation of a pacemaker can improve the quality of life and prognosis of patients with arrhythmia.In the past,permanent pacemaker implantation was performed in clinical practice,and the right ventricular pacing electrode was often fixed at the apex of the right ventricle,which belongs to non physiological pacing.Through long-term clinical follow-up,it was found that apex pacing can easily cause abnormal depolarization of the left ventricle,asynchronous contraction of the myocardium,and ultimately lead to myocardial fibrosis,which has adverse effects on the patient's cardiac function and psychological state.In recent years,Scholars have found that pacing in the right ventricular outflow tract septum is closer to the atrioventricular node and closer to the His bundle Purkinje fibers.The pacing impulse almost simultaneously expands towards both ventricles,closer to the physiological pacing state,thereby reducing the occurrence of cardiovascular events in patients.This article explores the impact of pacing in different parts of the heart on the cardiac function and psychological state of patients based on clinical data from the past three years.

Analysis of the Effect of Extracorporeal Diaphragmatic Pacing Combined with Noninvasive Ventilator on the Respiratory Function and Prognosis of COPD Patients

Objective: To investigate the effect of extracorporeal diaphragmatic pacing combined with noninvasive ventilators on the respiratory function and prognosis of chronic obstructive pulmonary disease (COPD) patients. Methods: A total of 50 COPD patients were selected between January 2023 to December 2023 and randomly grouped into an observation group and a control group, with 25 cases. The observation group was given extracorporeal diaphragm pacing combined with a noninvasive ventilator, while the control group was given a conventional treatment mode. After the treatment, the results of each index in the two groups were compared. Results: Compared with the diaphragm function indexes of the two groups, the data of the observation group were more dominant (P < 0.05). The rehospitalization rate of the observation group was lower than that of the control group (P < 0.05). The COPD assessment test (CAT) and mMRC (Modified Medical Research Council) Dyspnoea scale scores after treatment between the two groups were significantly different (P < 0.05). Compared with the control group, the lung function indexes of the observation group were more dominant (P < 0.05). Conclusion: Extracorporeal diaphragmatic pacing combined with a noninvasive ventilator promoted the improvement of the patient’s prognosis and improved their respiratory function.

PACE模式在现在分词作状语教学中的应用

语法教学是英语教学中必不可少的部分。PACE 模式较传统语法教学更加注重依托语境进行语法知识的输入加工、注重师生互动,更加强调学生的语言输出能力。本文以“现在分词作状语的用法”为例,探讨 PACE 模式“呈现 - 注意 - 共建 - 扩展”四个阶段在英语语法教学中的应用,总结其对语法教学的启发,旨在为语法教学提供思路,在课堂上提高语法教学的效率,促进学生语法能力的培养。

2019年捷豹I-PACE动力电池报警

故障现象 一辆2019年捷豹路虎生产的捷豹I-PACE纯电动SUV,VIN码为SADHA2B16K1F21^(****),行驶里程为44471km,车主反映该车无法挂挡行驶,且仪表台上显示“检测到电池故障”的提醒信息。

PACE教学模式在中职英语口语情境教学中的应用研究

中等职业英语教学目的是提升学生的交际能力,为其未来职业发展打基础。本文从教学实践出发,以高等教育出版社的《中职英语基础模块 3》U7 Natural Disasters 的口语课为实际案例,阐述将 PACE 教学模式应用于单元口语教学,探讨中职英语教师的口语教学新思路。基于教材中的口语内容,本文分析了教师如何呈现语言材料、引导学生注意语言形式、与学生共同建构对话框架、创设贴近学生生活和职业场景的任务来拓展对话学习,培养学生语言实际应用能力,提升英语学科核心素养。

捷豹路虎(中国)投资有限公司召回部分进口捷豹I-PACE系列纯电汽车

日前,捷豹路虎(中国)投资有限公司根据《缺陷汽车产品召回管理条例》和《缺陷汽车产品召回管理条例实施办法》的要求,向国家市场监督管理总局备案了召回计划。决定自即日起,召回2018年6月21日至10月2日期间生产的部分进口2019款捷豹I-PACE系列纯电汽车,共计113辆。

DYNAMIC BEHAVIOR ANALYSIS FOR LANDING-GEAR WITH DIFFERENT TYPES OF DUAL-CHAMBER SHOCK-STRUTS

In this paper three types of dual- chamber shock- struts are considered in dynamic analyses of landing-gear behavior during impact and taxi. Their dynamic characteristics are compared with each other according to calculation results, and some conclusions are presented.It is very helpful for selecting a suitable type of dual-chamber shock-strut in landing-gear design.

基于CiteSpace的醒脑静注射液研究现状可视化分析

目的 了解国内醒脑静注射液相关发展现状与研究热点。方法 检索中国知网(CNKI)2012年1月1日至2022年10月20日醒脑静注射液相关文献,运用文献计量学及CiteSpace 5.7.R1 SE软件对文献涉及的作者、机构、关键词进行可视化展示,并结合信息提取的方法对醒脑静注射液研究现状及发展趋势进行分析。结果 共纳入2321篇文献,作者分析显示杜守颖、陆洋是醒脑静注射液研究发文量最多的作者,并形成稳定的核心研究团队;发文机构呈现中医药院校及附属机构合作密切,跨地域合作较少的特点;关键词分析显示醒脑静注射液研究内容主要集中在临床应用、作用机制及质量控制等方面。结论 急性脑血管疾病、颅脑损伤、急性中毒等是醒脑静注射液的研究热点,中西医结合治疗及作用机制研究可能是未来研究的重点方向。

Comparison of electrocardiogram characteristics between left bundle branch pacing and right ventricular septal pacing in patients receiving pacemaker therapy

Background and Objective Cardiac pacing is an effective therapy in patients with bradycardia.Conventional right ventricular(RV)pacing is the source of ventricular dyssynchrony,leading to unfavorable clinical outcome.This study compared the electrocardiogram(ECG)characteristics during left bundle branch pacing(LBBP)with that during RV septal pacing(RVSP)which has been thought to be better than RV apical pacing.

Late rising right ventricular pacing lead threshold four yearsafter implantation of a dual chamber pacemaker

Late rising in pacing threshold is an uncommon complication of permanent pacing. Treatment with high dose systemic steroid could spare the patient another procedure. We report a case of late rising pacing threshold that responded to high dose sys-temic steroid which lowered the pacing threshold to one volt, then rose again to around 2 volts.

基于改进Self-paced Ensemble算法的浏览器指纹识别

浏览器指纹技术凭借其无状态、跨域一致等优点,已经被许多网站应用到用户追踪、广告投放和安全验证等方面。浏览器指纹识别的过程是典型的不平衡数据的分类过程。针对当前浏览器指纹长期追踪过程中存在数据样本类不平衡导致指纹识别准确度低、长期追踪易失效等问题,提出了改进的Self-paced Ensemble(Improved SPE,ISPE)方法应用于浏览器指纹识别。对浏览器指纹样本欠采样过程和集成学习单个分类器的训练过程进行了改进,重点针对难以识别的浏览器指纹,添加类注意力机制并优化自协调因子,使分类器在训练和识别浏览器指纹的过程中更加注重边界样本的分类效果,从而提升总体的浏览器指纹识别准确度。在所收集的3 483条指纹和开源数据集中的15 000条指纹上进行了实验,结果表明,ISPE算法在浏览器指纹匹配识别的F1-score达到95.6%,相比Bi-RNN算法提高了16.8%。

互动观念下的PACE模式在汉语语法教学中的应用

师生共同互动建构语言理解是影响汉语二语学习的关键因素。以往的语法教学研究,多关注学习者可理解输入的形式和量,往往忽略了教师和学习者以及同伴之间的有效互动。这样使得语言教学的“输入”和“输出”相分离,学习者很难在真实情景中达成交际。PACE语法教学模式强调通过互动来共同建构对语法的理解和使用,从而培养学习者的跨文化语言交际能力。基于PACE语法教学模式,结合汉语的特征,探索以学习者形成性评估和反思性学习为基础的汉语APACEA语法教学模式以及线上远程教学实践案例,实现汉语语法教学的优化路径。此教学法也存在一定局限性,仅适用于相对离散并大量存在于汉语教学中的语言结构。