左束支起搏心电图的特点观察

目的通过比较自身心律、左束支起搏、右室心尖部或右室流出道起搏时心电图的形态和QRS波群时限等,找寻左束支起搏心电图的特征表现。方法选取拟行左束支起搏42例患者,记录标准12导联体表心电图,通过测量,分别比较自身心律、左束支起搏及右室心尖部/右室流出道起搏时QRS波群时限、电轴、形态及ST段的差异。结果自身心律与左束支起搏相比,QRS波群时限无统计学差异(P=0. 49),但与右室心尖部/右室流出道起搏相比,具有显著差异(P <0. 000)。左束支起搏组,V1导联呈特征性"M"或"r SR"的比例为76. 19%;a VR导联亦可呈特征性"M"或"r SR"表现,比例为78. 57%。对于自身心律为右束支阻滞者,左束支区域起搏仅V1导联呈"M"或"r SR",a VR导联呈QS型,而无特征性"M"或"r SR"表现。与经典的右束支阻滞心电图比较:左束支起搏ST段和T波改变无规律性。结论左束支起搏心电图QRS波群时限和电轴与自身心律相比无显著差别,V1及a VR导联均可见特征性"M"或"r SR"表现,右束支阻滞患者仅V1导联呈特征性表现,但依靠心电图的特征性"M"或"r SR"改变判断起搏位点有局限性。     

右心室不同部位起搏的血流动力学比较

目的:探讨右室高位室间隔起搏与右室心尖部起搏的血流动力学不同。方法:60例缓慢心律失常患者,具有起搏器植入指征。随机分组,分别行右室高位室间隔起搏(A组)及右室心尖部起搏(B组)治疗。分别于术前、术后行心电图,超声心动图检查。观察QRS波时限,左心室射血分数(LVEF),左室舒张末期内径,每搏量(Sv),E峰值,E/A值,二尖瓣返流量。结果:右室高位室间隔起搏,与右室心尖部起搏比较,QRS波时限增宽程度小,LVEF以及Sv降低程度小。结论:右室高位室间隔起搏比右室心尖部起搏更接近生理性起搏,对血流动力学的不利影响较小,可能是一个更佳的起搏部位。     

室间隔不同部位起搏对QRS波的影响

QRS波可能与起搏器植入患者的预后有关,QRS波时限越长,左、右室电激动顺序和收缩的同步性越差,提示左室收缩功能越差。QRS波时限、形态、电轴及振幅在心尖部与室间隔部起搏不同,在不同的室间隔部起搏也有所不同。大多认为室间隔起搏的QRS波时限小于心尖部起搏,室间隔起搏的QRS波形态更接近生理性起搏,尤其是His束起搏,所以QRS波的时限和形态可能反映心脏起搏部位、左心功能、心脏电活动同步性等。但也有部分研究认为不同起搏方式对QRS波没有影响。     

不同部位起搏对体表心电图有关参数的影响

目的观察心脏不同部位起搏对体表心电图有关参数的影响。方法 10只健康猪,分别在右房(RA)起搏、右室心尖部心内膜起搏(RVEndo)及左室心外膜(LVEpi)起搏,记录并测量不同部位起搏后体表心电图12个导联的QRS波时限、QT间期、JT间期和T波峰-末间期(Tpe),计算Tpe平均值(TpeAVE)、Tpe最大值(TpeMAX)。结果 LVEpi起搏时QT间期、JT间期大于RA及RVEndo起搏时(P均<0.05);LVEpi起搏时TpeAVE,TpeMAX大于RA及RVEndo起搏时(P均<0.05),而RA与RVEndo起搏时此两指标无差异。结论 LVEpi起搏可能会增加健康心室整体复极离散。     

主动电极右室间隔部起搏的临床应用

目的 观察主动电极行右室流出道间隔部起搏的疗效.方法 以2008年5月至2013年5月在新乡市中心医院植入心脏起搏器的135例患者为研究对象,依据电极植入部位的不同分为四组:单腔起搏器(VVI)右室心尖部起搏组(52例,A组)、VVI右室间隔部起搏组(31例,B组)、双腔起搏器(DDD)右室心尖部起搏组(33例,C组)和DDD右室间隔部起搏组(19例,D组).分析四组在术后即刻及术后1、6、12、24个月的起搏阈值、导线阻抗、QRS波时限和心功能相关指标.结果 四组手术过程顺利,无并发症发生.B、D组术后即刻的起搏阈值较A、C组偏高,但差异无统计学意义(P>0.05).四组的起搏感知及阻抗均无明显差异.随访1年后,A、B、C组患者的心功能指标较D组有所下降,差异均有统计学意义(P<0.05).结论 右室流出道间隔部起搏较右室心尖部起搏更符合生理性起搏的特点,对心功能及心室重构的不良影响明显小于右室心尖部起搏.因此,DDD右室间隔部起搏是一种较为理想的心脏起搏方式.     

右室心尖部起搏患者起搏QRS波时限与左室结构和功能关系探讨

目的评价起搏QRS波时限与左心结构和功能的关系。方法入选106例右室心尖起搏患者,分成左室射血分数(LVEF)<0.55的病例组(n=48)和LVEF>0.55的对照组(n=58)。通过常规体表心电图测得起搏QRS波时限,行超声心动图检查获取左房内径(LAD)、收缩末期左室内径(LVESD)、舒张末期左室内径(LVEDD)、室间隔厚度(IVST)、左室后壁厚度(LVPWT)及LVEF,评价患者的纽约心功能分级,同时检测患者的N端-B型利钠肽前体(NT-proBNP)水平,分析起搏QRS波时限与以上各指标的关系。结果①起搏QRS波时限与LVEDD(r=0.577,P<0.001)、LVESD(r=0.627,P<0.001)、LAD(r=0.241,P=0.013)、IVST(r=0.345,P<0.001)、LVP-WT(r=0.349,P<0.001)均呈正相关,与LVEF负相关(r=-0.570,P<0.001),与纽约心功能分级正相关(r=0.527,P<0.001),与NT-proBNP对数正相关(r=0.265,P=0.024)。②以起搏QRS波时限≥200ms诊断左室收缩功能不全,灵敏度和特异度分别为85.42%和70.69%。结论对于右室心尖部起搏的患者,起搏QRS波时限是一个简便而实用的初步判断心脏结构和功能的指标。     

三度房室传导阻滞患者右室主/被动电极导线起搏的临床观察

目的观察不同电极(主动/被动)导线对三度房室传导阻滞患者的心脏功能、QRS波宽度、起搏参数的影响。方法将80例三度房室传导阻滞患者随机分两组,一组患者行主动电极导线右室间隔(RVS)起搏,一组行被动电极导线右室心尖部(RVA)起搏。分析两组心功能左室大小、左室射血分数(LVEF)、QRS波宽度、起搏参数变化。结果右室间隔起搏较心尖部起搏阈值、电极阻抗在术后1周及术后3月下降(P0.05),感知差异无统计学意义(P0.05);QRS波宽度RVS、RVA分别为(130±20)ms、(160±30)ms,差异有统计学意义(P0.05);心脏超声左室大小及LVEF术后3月两组无统计学意义(P0.05);但术后1年随访RVS及RVA组分别为:左室大小(47.30±1.97)mm及(49.01±2.40)mm,差异有统计学意义(P0.05);LVEF值(62.70±2.15)%,及(59.46±3.39)%,差异有统计学意义(P0.05)。结论对于起搏完全依赖患者,右室间隔部起搏的双室同步性优于右室心尖部起搏,且1年随访对心功能影响也较后者小。     

右室心尖部起搏和右室间隔部起搏对心脏血流动力学影响的对照研究

目的分析右室心尖部起搏和右室间隔部起搏对心脏血流动力学的影响。方法将62例心律失常患者按照随机数字表法分为观察组和对照组各31例,对照组给予右室心尖部起搏,观察组给予右室间隔部起搏,术后3个月比较两组患者的心室功能和血流动力学。结果观察组左室射血分数(LVEF)、每搏量(SV)、心脏指数(CI)均高于对照组,差异有统计学意义(P<0.05);观察组QRS波时限(QRSd)、收缩达峰值时间均低于对照组,差异有统计学意义(P<0.05)。结论右室间隔部起搏对左室的收缩功能影响较小,缩短了左室不同部位收缩达峰值时间,减小了QRSd宽度。     

右室流入道间隔部起搏对心脏血流动力学和心室激动顺序的影响

目的通过与右室心尖部(RVA)和右室流出道(RVOT)起搏比较,探讨右室流入道间隔部(RVIS)起搏对血流动力学和心室激动顺序的影响。方法选择24例阵发性室上性心动过速需行射频导管消融术(RFCA)且心功能正常和无室内传导阻滞的患者。在RFCA成功后,置入漂浮导管行血流动力学监测,用心室起搏电极以同一频率随机顺序起搏RVIS、RVOT和RVA,分别测定和比较各部位起搏时的心输出量(CO)、心脏指数(CI)、平均肺动脉压(mPAP)、肺毛细血管楔嵌压(PCWP)以及体表心电图上QRS波时限、JTc间期(经心率校正后的JT间期)和额面平均心电轴的变化。结果①RVIS、RVOT和RVA起搏时CO、CI、mPAP和PCWP等血流动力学指标均无差异(P>0.05)。②与正常窦性心律时QRS波时限比较,各部位起搏时QRS波时限均延长(P均<0.001),其中RVIS起搏时QRS波时限延长程度最小,RVA起搏时延长程度最大,各部位两两比较P均<0.05;JTc间期的变化有类似趋势,但各起搏部位之间比较无显著差异(P>0.05);与正常窦性心律时的额面平均心电轴比较,RVIS起搏时接近正常,RVOT起搏时电轴呈右偏趋势,RVA起搏时呈左偏趋势。结论①对心功能正常者RVIS起搏较RVOT和RVA起搏未表现出更佳的急性血流动力学效应。②RVIS起搏与RVOT和RVA起搏相比,能够保持相对正常的心室激动顺序。     

右室心尖部起搏时体表心电图V1导联呈右束支阻滞图形分析

目的分析右室心尖部起搏患者V1导联呈现右束支阻滞图形的特点、出现的可能机制以及鉴别诊断方法。方法选取北京大学人民医院2005—2007年于右室心尖部植入起搏电极的患者,分析患者完全右室起搏时V1导联呈右束支阻滞图形患者的超声心动图、胸部X线等资料,并与同期V1导联呈左束支阻滞图形变化的右室起搏患者以及植入左室心外膜电极的患者的临床资料以及体表心电图特点进行对比。结果共有9例患者术后完全心室起搏时V1导联呈右束支阻滞图形,术后超声心动图以及胸部X线检查证实起搏电极均位于右心室,QRS波平均电轴为-61.7±15.6,与随机选取50例术后体表心电图呈左束支阻滞的右室电极植入患者心电图相比,QRS波电轴差异无统计学意义(P>0.05),与7例行左室心外膜起搏者QRS波电轴差异有统计学意义(P<0.05)。呈右束支阻滞者其肢体导联I、aVL导联QRS波均直立,与呈左束支阻滞患者相同,而左室心外膜起搏者其I、aVL导联QRS波为负向。结论当患者V1导联呈右束支阻滞形态时可通过I、aVL导联QRS波形态和QRS波电轴可以判断是否为右室起搏。     

Acute biventricular pacing after cardiac surgery has no influence on regional and global left ventricular systolic function.

BACKGROUND: Cardiac resynchronization therapy has been shown to improve systolic function in patients with advanced chronic heart failure and electromechanical delay (QRS width > 120 ms). However, the effect of acute biventricular (BiV) pacing on perioperative haemodynamic changes is not well defined. In the present study, acute changes in regional left ventricular (LV) systolic function determined by tissue Doppler imaging (TDI) and global LV systolic function determined by the continuous cardiac output method were measured during various pacing configurations in patients with depressed LV systolic function undergoing heart surgery. METHODS: Twenty-six patients (age 68 +/- 8 years, 15 males) with depressed systolic LV function (LV ejection fraction 120 ms undergoing temporary epicardial BiV pacing after aortocoronary bypass and valve surgery were included. QRS duration on surface electrocardiogram (ECG), TDI (systolic velocities of septal and lateral mitral annulus), cardiac index (CI), right atrial pressure, pulmonary artery pressure (PAP), and pulmonary capillary wedge pressure (PCW) were measured during various pacing configurations [no pacing (intrinsic rhythm), right atrial-biventricular (RA-BiV pacing), right atrial-left ventricular (RA-LV), right atrial-right ventricular (RA-RV), and AAI pacing]. RESULTS: There were no differences in QRS duration during intrinsic rhythm, RA-BiV pacing, and AAI pacing. However, RA-LV and RA-RV stimulations showed a longer QRS duration (P < 0.01 vs. intrinsic rhythm, RA-BiV pacing, and AAI, respectively). Tissue Doppler velocities of the septal and lateral mitral annulus were comparable in all pacing modes. Neither CI nor PAP or PCW showed significant differences during the various pacing configurations. There was a positive correlation between regional (TDI) and global (CI) parameters of LV systolic function. Conclusions Biventricular pacing after heart surgery does not improve parameters of regional and global LV systolic function acutely in patients with heart failure and intraventricular conduction delay and, thus, may not reflect changes observed with chronic BiV pacing.     

不同心脏起搏方式对犬急性血液动力学及心肌力学的影响

通过采用 5种不同的心脏起搏方式 ,观察房室同步和心室激动顺序对犬急性血液动力学和心肌力学的影响。方法 :选用健康犬 10只 ,随机顺序进行右心房起搏 (RAP)、右房 His束顺序起搏 (AHSP)、右房 右室顺序起搏(AVSP)、His束近端起搏 (HBP)和右心室起搏 (RVP) ,在每种起搏稳定 5min后测定有关血液动力学和心肌力学参数。结果 :RAP和AHSP对血液动力学和心肌力学无显著影响 ;AVSP时心输出量 (CO)、等容收缩期左室压力最大上升速率 (+dp/dtmax)和等容舒张期左室压力最大下降速率 (-dp/dtmax)分别降低了 16 .32 % ,15 .0 1% ,15 .19% ;HBP时平均肺动脉压 (mPAP)、肺毛细血管楔压 (PCWP)、左室舒张末压 (LVEDP)均升高 ,而CO降低了 14.93 % ;RVP时mPAP、PCWP、LVEDP均明显升高 ,CO、+dp/dtmax和 -dp/dtmax分别降低了 2 3.95 % ,2 2 .2 8% ,19.74%。结论 :丧失房室同步活动引起左室前负荷变化 ,影响整体收缩功能 ;而心室激动顺序异常既影响左室收缩功能 ,也影响左室舒张功能     

AAI与VVI起搏对血液动力学及心钠素、肾素─血管紧张素系统影响的研究

观察１２例心律失常病人不同频率（７０，９０及１１０ｐｐｍ）ＡＡＩ和ＶＶＩ起搏时的心排出量（ＣＯ）、心脏指数（ＣＩ）、肺毛细血管楔嵌压（ＰＣＷＰ）、肺动脉压（ＰＡＰ）、右房压（ＲＡＰ）和血浆心钠素（ＡＮＰ）、肾素活性（ＰＲＡ）及血管紧张素ＩＩ（Ａ－ＩＩ）的变化。结果显示：ＡＡＩ起搏时，ＣＯ、ＣＩ显著高于ＶＶＩ起博和较慢的自身窦性心律时（Ｐ＜０．０５或０．０１），而无ＶＶＩ起搏所引起的ＰＣＷＰ、ＰＡＰ、ＲＡＰ、ＡＮＰ、ＰＲＡ及Ａ－ＩＩ等显著增高缺点。提示ＡＡＩ起博具有良好的血液动力学效应且不导致心脏内分泌激素异常而优于ＶＶＩ。     

右心室不同间隔部位起搏对左心室收缩功能的影响

目的 通过比较右心室心尖部及不同间隔部位（室间隔高位、中位、低位）起搏患者血浆N端B型利钠肽前体（NT-proBNP）水平、QRS时限,探讨右心室不同部位起搏对左心室收缩功能的影响.方法 选择植入VVI或DDD型起搏器患者122例,按照右心室不同起搏部位采用随机数字法分为4组：右心室心尖部起搏（RVAP）组、右心室间隔面起搏高位组（RVSP1组）、右心室间隔面起搏中位组（RVSP2组）、右心室间隔面起搏低位组（RVSP3组）,观察4组患者起搏器植入术前及术后18个月心电图QRS时限、血浆NT-proBNP水平、左心室射血分数（LVEF）、左心室舒张末期容积（LVEDV）以及出现心血管事件等指标.结果 所有患者均顺利完成导线和起搏器植入,并完成随访.心血管事件发生率比较,RVSP2组较RVAP组显著减低（4.5％对40％,P＜0.05）.术后RVAP组QRS时限最宽,RVSP2组起搏QRS时限最窄,差异有统计学意义（P＜0.05）;术后18个月患者RVAP、RVSP1、RVSP3组NTproBNP均有不同程度增加,其中RVAP组最高（P＜0.05）;4组患者LVEDV术后18个月与术前比较,RVSP3组与RVAP组有不同程度增加（P＜0.05）,其中RVAP组增加显著（P＜0.05）;术后18个月RVSP组LVEF均无显著减低（P＞0.05）,而RVAP组显著减低（P＜0.05）.结论 选择右心室中位间隔部起搏,起搏QRS时限最窄,患者NT-proBNP水平低,可能为起搏器植入患者理想的起搏部位.     

右室间隔起搏与心尖部起搏对完全性房室传导阻滞患者心功能影响的比较

目的:初步探讨右室间隔起搏(RVSP)和右室心尖部起搏( RVAP)对完全房室传导阻滞( CAVB) 患者心功能的影响。方法:87例因CAVB植入起搏器的患者, 其中45例行RVSP术(RVSP组)，42例行RVAP术(RVAP组)，分别对术前及术后6、12和18个月，患者的QRS波时限、左室舒张末内径（LVEDD）、 左室射血分数（LVEF）、每搏量（SV）、心脏指数（CI）、加速度指数（ACI）进行检查比较。结果:所有患者均完成12个月随访, 79例完成18个月随访。术后RVAP组QRS波时限较RVSP组明显增宽(P<0.05)，术后12个月RVAP组LVEF、SV、ACI均较RVSP组明显降低(P<0.05)，术后18个月RVAP组LVEDD较RVSP组明显增大(P<0.05)，RVAP组CI均较RVSP组降低，但尚未达到显著性差异。结论:RVSP较RVAP有利于CAVB患者心功能的保护。     

Percentage of peak-to-peak pulsatility of portal blood flow can predict right-sided congestive heart failure

AIM: To study the change of portal blood flow for the prediction of the status of right-sided heart failure by using non-invasive way.METHODS: We studied 20 patients with rheumatic and atherosclerotic heart diseases. All the patients had constant systemic blood pressure and body weight 1 week prior to the study. Cardiac index (CI), left ventricular end-diastolic pressure (LVEDP), mean aortic pressure (AOP), pulmonary wedge pressure (PWP), mean pulmonary arterial pressure (PAP), mean right atrial pressure (RAP), right ventricular end-diastolic pressure (RVEDP) were recorded during cardiac catheterization. Ten patients with RAP＜10 mmHg were classified as Group 1. The remaining 10 patients with RAP ≥ 10 mmHg were classified as Group 2. Portal blood velocity profiles were studied using an ultrasonic Doppler within 12h after cardiac catheterization.RESULTS: CI, AOP, and LVEDP had no difference between two groups. Patients in Group 1 had normal PWP (14.6±7.3mmHg), PAP (25.0±8.2 mmHg), RAP (4.7±2.4 mmHg), and RVEDP (6.4±2.7 mmHg). Patients in Group 2 had increased PWP (29.9±9.3 mmHg), PAP (46.3±13.2 mmHg), RAP (17.5±5.7 mmHg), and RVEDP (18.3±5.6 mmHg) (P＜0.001).Mean values of maximum portal blood velocity (Vmax), mean portal blood velocity (Vmean), cross-sectional area (Area)and portal blood flow volume (PBF) had no difference between 2 groups. All the patients in Group 1 had a continuous antegrade portal flow with a mean percentage of peak-topeak pulsatility (PP) 27.0±8.9 % (range: 17-40 %). All the patients in Group 2 had pulsatile portal flow with a mean PP 86.6±45.6 (range: 43-194 %). One patient had a transient stagnant and three patients had a transient hepatofugal portal flow, which occurred mainly during the ventricular systole. Vmax, Vmean and PBF had a positive correlation with CO (P＜0.001) but not with AOP, LVEDP, PWP, PAP,RAP, and RVEDP.PP showed a good correlation (P＜0.001)with PWP, PAP, RAP, and RVEDP but not with CI, AOP, and LVEDP. All the patients with PP ＞40 % had a right-sided heart failure with a RAP=10 mmHg.CONCLUSION: The measurement of PP change is a simple and non-invasive way to identify patients with right heart failure.     

Comparison of apical and infundabular pacing in patients with primary dilated or ischemic cardiomyopathy

Dual chamber pacing has been proposed as an alternative treatment to patients with cardiac failure refractory to optimal medical therapy. The influence of the site of ventricular pacing was studied in 15 patients with an average age of 68.7 +/- 8.7 years with dilated cardiomyopathies and an average left ventricular ejection fraction of 22.3 +/- 6.8%. Three temporary USCI electrodes were positioned in the right atrium, the right ventricular outflow tract (RVOT) and the right ventricular apex. The average duration of the QRS complexes and the haemodynamic parameters (PAP, PCP and cardiac index) were measured in sinus rhythm and during DDD apical, RVOT and simultaneous apical and RVOT pacing. The RVOT and simultaneous pacing significantly reduced the QRS duration (135 +/- 14 ms and 137 +/- 17 ms, p < 0.0001 respectively) compared with apical pacing (150 +/- 19 ms). The mean PAP and mean PCP remained unchanged in the different modes of pacing but the cardiac index increased significantly during RVOT pacing (2.99 +/- 0.67 l/min/m2) and simultaneous pacing (3 +/- 0.77 l/min/m2) compared with apical pacing (2.66 +/- 0.62 l/min/m2) (p < 0.001 and p < 0.01 respectively) and compared with sinus rhythm (2.62 +/- 0.7 l/min/m2) (p < 0.001 and p < 0.005 respectively). This study suggests that better results may be obtained with RVOT screw in lead than with the traditional right ventricular apical electrode.     

Effects of Multisite Ventricular Pacing on Cardiac Function in Normal Dogs and Dogs with Heart Failure

INTRODUCTION: We studied the effects on cardiac function of pacing two right and two left ventricular sites in normal and failing hearts with a normal QRS duration. METHODS AND RESULTS: Hemodynamic parameters were studied in isoflurane-anesthetized dogs with normal hearts and dogs with heart failure induced by rapid ventricular pacing. Unipolar intramyocardial electrodes were placed at the high right atrium and the apex (A) and base (B) of the left (L) and right (R) ventricles (V). Data were collected after pacing for 5 to 20 minutes. In normal dogs, without bundle branch block (BBB), pacing at either the apex or the base of the left ventricle increased cardiac output by approximately 10% compared with right ventricular apex (RVA) pacing with an AV delay of 0 msec. Positive dP/dt increased approximately 10% during four-site left and right ventricular apex and base (LRVAB) pacing compared with RVA pacing. In dogs with heart failure but without BBB, cardiac output increased by 8.5% (P < 0.01) during four-site ventricular pacing with AV delays of 0 and 60 msec compared with RVA pacing. Positive dp/dt increased by 23.5% (P < 0.001) with an AV delay of 0 msec and 9.6% (P < 0.001) with an AV delay of 60 msec during LRVAB pacing compared with RVA pacing. His-bundle pacing was associated with increased cardiac output compared with RVA pacing. CONCLUSIONS: We conclude that pacing simultaneously at two right and two left ventricular sites significantly improves cardiac function compared with single RVA pacing, with or without sequential AV synchrony, in dogs with rapid ventricular pacing-induced heart failure and no BBB.