三维斑点追踪评价左束支起搏对左心室同步性的影响 The Effects of Left Bundle Branch Pacing Mode on Left Ventricular Synchrony Evaluated by Three-Dimensional Speckle Tracking Imaging

目的：应用三维斑点追踪技术对比分析左束支起搏与右室流出道起搏对左心室收缩的影响。方法：对25例左束支起搏和25例右室流出道起搏术后的患者进行观察性研究，入选者均为病态窦房结综合征患者。用三维斑点追踪技术于术前、术后1个月、术后6个月采集患者左心室舒张和收缩末容积、射血分数，左心室壁总体纵向、径向、周向应变，计算心动周期标化的左心室壁16节段达最小收缩容积时间标准差，同期采集NT-proBNP和QRS波宽度。结果：左束支起搏状态下左心室应变与同步性与生理传导无统计学差异(P < 0.05)；与右室流出道起搏比较，前者应变更大，心肌最小收缩容积时间标准差更小，差异有统计学意义(P > 0.05)。结论：左束支起搏是一种生理性起搏方式，左束支起搏状态下的心功能参数优于右室流出道起搏，三维斑点追踪技术可早期发现左心室收缩功能的变化。

关键词

心脏起搏，人工，左束支，右心室流出道，斑点追踪成像，心室功能，左

The Effects of Left Bundle Branch Pacing Mode on Left Ventricular Synchrony Evaluated by Three-Dimensional Speckle Tracking Imaging

Yuanjie Qi^1*, Liang Zhao², Yunyun Ma³, Huifang Dong⁴, Jinshan Wo^1#

¹Department of Cardiology, The Affiliated Hospital of Qingdao University, Qingdao Shandong

²Department of Cardiac Ultrasound, The Affiliated Hospital of Qingdao University, Qingdao Shandong

³Emergency Department, The Affiliated Hospital of Qingdao University, Qingdao Shandong

⁴Operating Room, The Affiliated Hospital of Qingdao University, Qingdao Shandong

Received: Dec. 11^th, 2020; accepted: Dec. 26^th, 2020; published: Jan. 14^th, 2021

ABSTRACT

Objective: The purpose of this study is to compare the effects of left bundle branch pacing and right ventricular outflow tract pacing on left ventricular systole using 3D speckle tracking technique. Methods: Twenty-five patients with left bundle branch pacing and twenty-five patients with right ventricle outflow tract pacing were enrolled in an observational study. All of them were diagnosed with sick sinus syndrome. Three-dimensional speckle tracking imaging technology was taken to obtain left ventricular end-diastolic volume, end-systolic volume, ejection fraction, global longitudinal strain, radial strain and circumferential strain, before and one or six months after operation. Then percentage of standard deviation of time, when the left ventricular sixteen segments reached minimum end-systole in cardiac cycle, would be calculated. Meanwhile, the information about the plasma NT-proBNP levels and QRS complex duration were detected. Results: Compared with the self‐conduction status, no significant difference was found in parameters of left ventricular strain and systolic synchrony when the mode was left bundle branch pacing (P < 0.05). The difference of cardiac function parameters, between the right ventricle outflow tract pacing group and the left bundle branch pacing group, was statistically significant (P < 0.05); with the strain increased and standard deviation of time shortened when pacing with left bundle branch. Conclusion: Left bundle branch pacing is a physiological pacing mode. Left ventricular function parameters in left bundle branch pacing are superior to those of right ventricle outflow tract pacing group. Three-dimensional speckle tracking imaging technology can evaluate left ventricular metergasis more sensitively.

Keywords:Cardiac Pacing, Artificial, Left Bundle Branch, Right Ventricle Outflow Tract, Speckle Tracking Imaging, Ventricular Function, Left

This work is licensed under the Creative Commons Attribution International License (CC BY 4.0).

http://creativecommons.org/licenses/by/4.0/

1. 引言

自心脏起搏器应用于临床以来，生理性起搏位点一直是研究热点。希氏束起搏(HBP)传导顺序与生理性传导顺序一致，激动沿希浦系统下传，保持了电学同步 [1]，但植入困难 [2]、起搏参数不稳定 [3] [4]、无法纠正束支传导阻滞等缺点限制了其发展。新兴的左束支起搏(LBBP)通过夺获左束支或其分支，使激动沿左束支下传，实现左心室电学同步，较HBP起搏参数稳定、安全性高、应用范围广 [5] [6] [7]，可能成为替代HBP的另一种生理性起搏方式。但LBBP左心室收缩机械同步性是否优于传统的右室流出道起搏(RVOTP)还有待进一步验证。本研究旨在应用三维斑点追踪成像(3D-STI)技术评价LBBP对左心室收缩机械同步性的影响，为临床上选择更生理的起搏位点提供参考。

2. 资料和方法

2.1. 研究对象

选取2018-09-01至2020-08-31因病态窦房结综合征(SSS)来我院行永久性双腔起搏器植入术的患者。根据起搏位点的不同，将患者分成LBBP、RVOTP两组。排除标准：1) 二维心脏超声提示心脏结构异常者；2) 左心室射血分数 < 50%者；3) 心电图示长QT间期综合征、Brugada综合征、束支传导阻滞或QRS波时限(QRSd) > 110 ms者；4) 合并基础心脏病者，如心瓣膜病、缺血性心脏病、心肌病等；5) 合并影响心脏功能的基础疾病者，如糖尿病、尿毒症等。本研究已经过青岛大学附属医院伦理委员会批准，所有患者术前均签署知情同意书。两组患者的基线资料无统计学差异(表1)。

2.2. 手术方法

LBBP组：锁骨下静脉入路，C315外鞘(Medtronic，美国)送3830主动螺旋固定导线(Medtronic，美国)至右心室。右前斜30˚下标记HIS电位，导线头端移至其前下方，垂直于室间隔，逆时针旋入。V₁导联QRS波态逐渐由“W”型变为rSR’或QR型。左前斜45˚下造影确认导线头端旋入深度适中。RVOTP组：锁骨下静脉入路，7F可撕开鞘送3830主动螺旋固定导线(Medtronic，美国) 至右心室流出道间隔部，固定。体表心电图V₁导联呈QS型。

2.3. 观察指标

分别于术前、术后1个月起搏状态下、术后6个月起搏状态下采集患者的心脏超声、心电图、NT-proBNP信息。心脏超声信息采集方法：Philips EPIQ 7C彩色多普勒超声诊断仪、X5-1探头(频率1~5 MHz)、TOMTEC软件。连接同步心电图，超声图像清晰显示心内膜，采集3个心动周期的心尖四腔观图像。TOMTEC软件自动获取左室舒张末期容积(LVEDV)、左室收缩末期容积(LVESV)、左室射血分数(LVEF)，计算左心室16节段达最小收缩容积时间标准差(Tmsv16-SD)，R-R间期标准化后得到Tmsv16-SD/R-R，计算16节段的纵向、径向、周向收缩期峰值应变的平均值，作为左室整体纵向应变(GLS)、径向应变(GRS)、周向应变(GCS)。

2.4. 统计分析

SPSS 25.0软件分析。计量、计数资料分别以均数±标准差、频数表示，用到的统计学方法有Shapiro-Wilk正态性检验、独立样本t检验、单因素重复测量方差分析、Bonferroni检验、χ²检验。所有检验为双侧检验，P < 0.05差异有统计学意义。

3. 结果

组间比较：术前两组患者所有观察指标差异无统计学意义(P > 0.05)。术后LBBP组QRSd明显窄于RVOTP组(P < 0.01)，Tmsv16-SD/RR明显小于RVOTP组(P < 0.01)。术后1个月LBBP组GLS (绝对值)大于RVOTP组(P < 0.05)，术后6个月差异更明显(P < 0.01)。两组GCS、GRS和LVEDV、LVESV、LVEF、NT-proBNP差异无统计学意义(表1~4)。

组内比较：LBBP组术前、术后各项观察指标差异均无统计学意义(P > 0.05)。RVOTP组术后QRSd较术前明显增宽，术后Tmsv16-SD/RR持续延长，差异均有统计学意义(P < 0.01)；GLS、GCS变化趋势与Tmsv16-SD/RR一致，其中，GCS变化速度较GLS缓，术后6个月GCS与术前差异有统计学意义(P < 0.05)；LVEF有下降趋势，但差异无统计学意义(P > 0.05)；GRS和LVEDV、LVESV、NT-proBNP均无明显变化(表1~4)。

Table 1. Comparison of baseline data between two groups ( X ¯ ± S D )

表1. 两组患者基线资料比较( $\bar{X} \pm S D$ )

注：RVOTP = 右室流出道起搏，LBBP = 左束支起搏，QRSd = QRS波宽度，LVEDV = 左心室舒张末容积，LVESV = 左心室收缩末容积，LVEF = 左心室射血分数。

Table 2. Comparison of QRSd between two groups ( X ¯ ± S D , n = 25, ms)

表2. 两组患者心电图QRSd比较( $\bar{X} \pm S D$ , n = 25, ms)

注：同期两组比较^aP < 0.01；组内与术前比较^cP < 0.01，RVOTP = 右室流出道起搏，LBBP = 左束支起搏，QRSd = QRS波宽度。

Table 3. Comparison of myocardial strain and mechanical synchronization parameters between two groups ( X ¯ ± S D , n = 25, %)

表3. 两组患者心肌应变与机械同步性参数比较( $\bar{X} \pm S D$ , n = 25, %)

注：同期组间比较^aP < 0.01，^bP < 0.05；组内与术前比较^cP < 0.01，^dP < 0.05；组内与术后1个月比较^eP < 0.01，^fP < 0.05，RVOTP = 右室流出道起搏，LBBP = 左束支起搏，GLS = 左心室整体纵向应变，GRS = 左心室整体径向应变，GCS = 左心室整体周向应变。

Table 4. Comparison of conventional echocardiographic parameters and NT-proBNP between two groups ( , n = 25)

表4. 两组患者常规心脏超声参数与NT-proBNP比较( $\bar{X} \pm S D$ , n = 25)

注：RVOTP = 右室流出道起搏，LBBP = 左束支起搏，LVEDV = 左心室舒张末容积，LVESV = 左心室收缩末容积，LVEF = 左心室射血分数。

4. 讨论

左心室收缩同步性与心功能关系密切，既往研究 [8] [9] [10] 表明心室收缩失同步可增加心衰发生率，所以评价LBBP与RVOTP对左心室收缩同步性影响意义重大。

3D-STI在三维空间上追踪心肌回声斑点的位置与运动，定量评价心肌应变，无角度依赖性和失追踪 [11]。应变即某一节段形变占其初始长度的百分比，表示心肌形变程度，主要分为纵向、径向、周向应变 [12]。此次研究结果显示LBBP组术前、后应变无明显变化，提示LBBP对心肌总体收缩无影响。RVOTP组GLS持续下降(P < 0.05)，GCS也呈下降趋势，但下降速度较GLS慢，GRS无明显变化。此种变化可能与心室壁构成有关，心内膜下心肌层呈右手螺旋状斜行 [11] [13]，收缩时主要表现为纵向应变与周向应变，起搏早期心内膜下心肌收缩受损为主，故GLS、GCS早期即发生改变，但全心70%心肌纤维为纵向纤维，心肌的纵向应变与心肌收缩功能联系更紧密，因此心肌收缩功能受损早期纵向应变较周向应变变化显著，这与国外学者所得GLS与LVEF相关性良好结论相符 [14]。径向应变表示心室壁在短轴方向增厚的程度，是三层心肌共同运动的结果，在收缩功能降低早期，心室固有层和心外膜下心肌层未受累时可无明显变化。为避免心率的影响，将Tmsv16-SD进行R-R间期标化，数值越小表示心肌收缩机械同步性越好。LBBP组术前、术后的Tmsv16-SD/R-R无统计学差异(P < 0.05)，表明起搏对心肌收缩同步性无影响，这与前期国内外学者用组织多普勒或SPECT研究心肌收缩同步性的结果一致 [15] [16] [17]。RVOTP组术后起搏传导的Tmsv16-SD/R-R进行性延长(P < 0.01)，与同期LBBP组比较，差异显著(P < 0.01)，提示RVOTP对心肌机械同步性产生不良影响，机械同步性随起搏时间延长而进一步恶化。ROVTP组术后LVEF呈下降趋势，但组间、组内差异无统计学意义，两组LVEDV、LVESV组间、组内比较均无统计学差异，提示LS、Tmsv16-SD/R-R较LVEDV、LVESV、LVEF这些常规心脏超声参数敏感，可早期反映心脏收缩状态变化。

电学同步性参数比较，LBBP组QRSd较ROVTP组QRSd窄，与生理传导的QRSd无明显差异，而ROVTP术后QRSd较术前明显增宽，提示LBBP可模拟生理电激动，同步激动双心室，再次验证了陈璐等研究者的结论 [18]。左束支分布丰富 [19]，LBBP直接激动左束支 [20]，激动沿左束支众多分支及广泛的浦肯野纤维快速下传。RVOTP则激动室间隔左右侧的心肌，间接夺获传导组织。故LBBP较ROVTP电激动下传更迅速、同步。本研究结果表明RVOTP组Tmsv16-SD/R-R提示机械同步性随起搏时间延长而恶化，但QRSd未显示电学同步性进行性下降趋势，结合既往研究结果 [21]，分析原因主要为电–机械活动延迟耦联可使收缩失同步的心肌产生正常QRSd，即QRSd正常不等同于心脏机械同步。

本研究中两组患者术前、后NT-proBNP均在正常范围内，可能与患者术前心功能良好、心腔大小正常，术后随访时间短，患者心功能水平尚在代偿期等有关。

本研究的局限性：1) 随访时间短，长期结果尚需继续随访；2) 样本量少，试验结果存在偶然性，应扩大样本量进一步研究；3) 检查手段受限，三维心脏超声的时间和空间分辨力不足 [22]，测量值有偏差。

5. 结论

LBBP是一种生理的起搏方式。LBBP状态下左心室机械收缩同步性与自身传导无差异，优于RVOTP组。长期RVOTP导致心功能进行性下降。3D-STI可定量评估心肌收缩及同步性，较常规超声心动图和生化检查更早期发现心脏收缩功能下降，其中LS、Tmsv16-SD/R-R是敏感指标。

文章引用

齐元杰,赵亮,马云云,董慧芳,沃金善. 三维斑点追踪评价左束支起搏对左心室同步性的影响
The Effects of Left Bundle Branch Pacing Mode on Left Ventricular Synchrony Evaluated by Three-Dimensional Speckle Tracking Imaging[J]. 临床医学进展, 2021, 11(01): 106-111. https://doi.org/10.12677/ACM.2021.111015

参考文献

1. Vijayaraman, P., Bordachar, P. and Ellenbogen, K.A. (2017) The Continued Search for Physiological Pacing: Where Are We Now? Journal of the American College of Cardiology, 69, 3099-3114. https://doi.org/10.1016/j.jacc.2017.05.005

2. Vijayaraman, P., Chung, M.K., Dandamudi, G., et al. (2018) His Bundle Pacing. Journal of the American College of Cardiology, 72, 927-947. https://doi.org/10.1016/j.jacc.2018.06.017

3. Zanon, F., Ellenbogen, K.A., Dandamudi, G., et al. (2018) Permanent His-Bundle Pacing: A Systematic Literature Review and Meta-Analysis. Europace, 20, 1819-1826. https://doi.org/10.1093/europace/euy058

4. Vijayaraman, P., Dandamudi, G., Zanon, F., et al. (2018) Permanent His Bundle Pacing: Recommendations from a Multicenter His Bundle Pacing Collaborative Working Group for Standardization of Definitions, Implant Measurements, and Follow-Up. Heart Rhythm, 15, 460-468. https://doi.org/10.1016/j.hrthm.2017.10.039

5. Vijayaraman, P., Subzposh, F.A., Naperkowski, A., et al. (2019) Prospective Evaluation of Feasibility and Electrophysiologic and Echocardiographic Characteristics of Left Bundle Branch Area Pacing. Heart Rhythm, 16, 1774-1782. https://doi.org/10.1016/j.hrthm.2019.05.011

6. Zhang, S., Zhou, X. and Gold, M.R. (2019) Left Bundle Branch Pacing: JACC Review Topic of the Week. Journal of the American College of Cardiology, 74, 3039-3049. https://doi.org/10.1016/j.jacc.2019.10.039

7. Chen, K., Li, Y., Dai, Y., et al. (2019) Comparison of Electrocardiogram Characteristics and Pacing Parameters between Left Bundle Branch Pacing and Right Ventricular Pacing in Patients Receiving Pacemaker Therapy. Europace, 21, 673-680. https://doi.org/10.1093/europace/euy252

8. Cho, S.W., Gwag, H.B., Hwang, J.K., et al. (2019) Clinical Features, Predictors, and Long-Term Prognosis of Pacing-Induced Cardiomyopathy. European Journal of Heart Failure, 21, 643-651. https://doi.org/10.1002/ejhf.1427

9. Cicchitti, V., Radico, F., Bianco, F., et al. (2016) Heart Failure Due to Right Ventricular Apical Pacing: The Importance of Flow Patterns. Europace, 18, 1679-1688. https://doi.org/10.1093/europace/euw024

10. Ogano, M., Iwasaki, Y.K., Tanabe, J., et al. (2016) Restoration of Ventricular Septal Hypoperfusion by Cardiac Resynchronization Therapy in Patients with Permanent Right Ventricular Pacing. International Journal of Cardiology, 224, 353-359. https://doi.org/10.1016/j.ijcard.2016.09.031

11. Biswas, M., Sudhakar, S., Nanda, N.C., et al. (2013) Two- and Three-Dimensional Speckle Tracking Echocardiography: Clinical Applications and Future Directions. Echocardiography, 30, 88-105. https://doi.org/10.1111/echo.12079

12. Caspar, T., Fichot, M., Ohana, M., et al. (2017) Late Detection of Left Ventricular Dysfunction Using Two-Dimensional and Three-Dimensional Speckle-Tracking Echocardiography in Patients with History of Nonsevere Acute Myocarditis. Journal of the American Society of Echocardiography, 30, 756-762. https://doi.org/10.1016/j.echo.2017.04.002

13. Sengupta, P.P., Khandheria, B.K., Korinek, J., et al. (2006) Apex-to-Base Dispersion in Regional Timing of Left Ventricular Shortening and Lengthening. Journal of the American College of Cardiology, 47, 163-172. https://doi.org/10.1016/j.jacc.2005.08.073

14. Hayat, D., Kloeckner, M., Nahum, J., et al. (2012) Comparison of Real-Time Three-Dimensional Speckle Tracking to Magnetic Resonance Imaging in Patients with Coronary Heart Disease. The American Journal of Cardiology, 109, 180-186. https://doi.org/10.1016/j.amjcard.2011.08.030

15. Hasumi, E., Fujiu, K., Nakanishi, K., et al. (2019) Impacts of Left Bundle/Peri-Left Bundle Pacing on Left Ventricular Contraction. Circulation Journal, 83, 1965-1967. https://doi.org/10.1253/circj.CJ-19-0399

16. Hou, X., Qian, Z., Wang, Y., et al. (2019) Feasibility and Cardiac Synchrony of Permanent Left Bundle Branch Pacing through the Interventricular Septum. Europace, 21, 1694-1702. https://doi.org/10.1093/europace/euz188

17. 黄心怡, 蔡彬妮, 李琳琳, 等. 组织多普勒技术评价左束支区域起搏对心脏收缩同步性的影响[J]. 中华超声影像学杂志, 2019(4): 289-294.

18. 陈璐, 马雪兴, 翁嘉懿, 等. 左束支区域起搏的临床应用初探[J]. 南京医科大学学报(自然科学版), 2019, 39(6): 818-821.

19. Elizari, M.V. (2017) The Normal Variants in the Left Bundle Branch System. Journal of Electrocardiology, 50, 389-399. https://doi.org/10.1016/j.jelectrocard.2017.03.004

20. Huang, W., Chen, X., Su, L., et al. (2019) A Beginner’s Guide to Permanent Left Bundle Branch Pacing. Heart Rhythm, 16, 1791-1796. https://doi.org/10.1016/j.hrthm.2019.06.016

21. Ghio, S., Constantin, C., Klersy, C., et al. (2004) Interventricular and Intraventricular Dyssynchrony Are Common in Heart Failure Patients, Regardless of QRS Duration. European Heart Journal, 25, 571-578. https://doi.org/10.1016/j.ehj.2003.09.030

22. 覃小娟, 谢明星, 吕清, 等. 超声三维斑点追踪成像技术评价慢性心力衰竭患者左心室整体应变的初步研究[J]. 中华医学超声杂志(电子版), 2010, 7(8): 1332-1337.

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