不同起搏方式对患者左心结构与功能及NT-proBNP的影响

【目的】探究生理性起搏（DDD）和非生理性起搏（VVI）对心脏结构及 N-末端脑钠肽前体（NT-proBNP）的影响,并为起搏器植入心脏后的应对策略积累经验。【方法】选取本院心内科于2012年1～12月收治的65例接受起搏器治疗患者,根据不同起搏方式进行分组。其中对照组患者采取 VVI,研究组采取DDD,比较两组患者在植入起搏器前后左心室结构和功能及 NT-proBNP水平变化。【结果】两组患者在植入起搏器前的左心房内径（LAD）、左心室舒张末期内径（LVD）、室间隔厚度（IVST）、左心室后壁厚度（PWT）、左心室射血分数（EF）方面差异无统计学意义（P ＞0．05）;植入起搏器后,研究组 LAD小于对照组（P ＜0．05）,EF高于对照组（P ＜0．05）。两组患者在起搏器植入前 NT-proBNP 值差异无统计学意义（P ＞0．05）;安置起搏器后,研究组 NT-proBNP值低于对照组（P ＜0．05）。【结论】有起搏器植入适应证的患者,为减少起搏对心脏结构和功能的影响,应当选择房室顺序起搏为宜。     

右心室不同部位起搏对左心室重构的影响

右心室不同部位起搏产生非生理性的电机械不同步,影响左心室结构和功能,有可能会产生心肌重构.长期右心室心尖部(RVA)起搏产生病理性左心室重构,而右心室流出道(RVOT)及双部位右心室起搏对左心室重构的影响仍有待进一步研究.左心室重构为一系列复杂的分子和细胞机制造成心肌结构、功能和表型的变化,临床上可见心肌重量和心室容量的增加,以及心室形状的改变,横径增加呈球状.心肌重构是导致心力衰竭发生发展的基本机制,是影响多种心脏疾病预后的重要因素.而随着对生理性起搏的认识,长期右心窒不同部位起搏其电机械激动顺序、血流动力学不同,对左心室结构和功能产生影响,有可能会导致左心室重构.现对右心室不同部位起搏对左心室重构的影响综述如下.     

不同起搏方式左心室收缩同步性超声评价的对比研究

目的：应用二维斑点追踪显像(2D-STI)和组织多普勒成像(TDI)技术对比分析直接希氏束起搏(direct His-bundle pacing,DHBP)与右室心尖部起搏(right ventricular apical pacing,RVAP)时左室收缩同步性,并探讨2D-STI 和 TDI 在评价左室收缩同步性中的应用价值。方法24例植入有 DHBP 和RVAP起搏方式的永久起搏器患者,分别在 DHBP 和 RVAP 状态下,采用2D-STI 测量左室18节段收缩期径向应变达峰时间,计算其标准差(Trs-SD)及最大差(Trs-Dif)、左室短轴乳头肌水平的前间隔与左室后壁收缩期径向应变达峰时间的差值(Tas-post);采用TDI测量左室12节段收缩期速度达峰时间,计算其标准差(Ts-SD)及最大差(Ts-Dif)。结果与 RVAP 相比,DHBP 状态下各左室收缩同步性参数均明显缩短,差异有统计学意义(均P <0.01)。DHBP时2D-STI对左室收缩同步性检出率优于TDI,RVAP时2D-STI对左室收缩不同步检出率亦优于TDI,差异均有统计学意义(均P <0.05)。结论 DHBP时左室收缩同步性及心功能均优于 RVAP;RVAP可能会引起左室收缩不同步;2D-STI 和 TDI 均能定量评价左室收缩同步性,2D-STI较TDI检出率更高。     

右心室不同部位起搏对心功能的影响

目的研究右心室不同部位起搏对患者心功能的影响,探求最有利的永久性右心室起搏部位。方法 54例Ⅱ度Ⅱ型或Ⅲ度房室传导阻滞行永久性起搏器的患者,按起搏部位分为右心室心尖(RVA)组、右心室流出道(RVOT)组、右心室流入道(RVIT)组,分别观察三组术前及术后6个月QRS间期(QRSd)、左心室射血分数(LVEF)、每搏输出量(SV)、每分输出量(CO)、左心室收缩末内径(LVESD)、左心室舒张末内径(LVEDD)的差异,并比较三组间术后6个月上述参数的差异。结果与术前相比,三组起搏术后6个月QRSd均显著增加(P<0.01);RVA组起搏术后6个月LVEF、SV、CO均显著降低(P<0.05);RVOT组与RVIT组起搏术后6个月LVEF、SV、CO均无显著变化(P>0.05);三组起搏术后6个月LVESD、LVEDD均无显著变化(P>0.05)。三组间起搏后6个月QRSd有统计学差异,QRSd依次为RVA组>RVOT组>RVIT组(P<0.01);而三组间起搏后6个月LVEF、SV、CO、LVESD、LVEDD无统计学差异(P>0.05)。结论右心室流入道起搏QRSd最小,可能是理想的右心室起搏部位。     

右心室不同部位起搏对心脏结构和左心功能的影响

[目的]对比研究右心室不同部位起搏对患者心脏结构和左心功能的影响.[方法]90例Ⅲ度或高度房室传导阻滞患者, 随机分为三组, A组行右室流入道（RVIS）间隔部起搏,B组行右室流出道（RVOT）间隔部起搏,C组行右心室心尖部（RVA）起搏. 观察三组手术中情况,监测术中血流动力学变化及手术曝光时间,比较三组术后随访的起搏器工作情况,心电图QRS波宽度,左心功能及血浆中B型钠尿肽（BNP）的差异.[结果]术中监测血流动力学,A组及B组明显优于C组.术后随访观察,A组及B组心电图QRS波宽度明显窄于C组,A组及B组具有更好的心脏功能.[结论]右心室间隔部起搏无论右室流出道起搏还是右室流入道间隔部起搏都是安全,有效的,比右室心尖部起搏更有利于双心室电激动的同步性,且长期对心脏结构及心功能影响也较少.     

组织多普勒显像评价右心室不同部位起搏对左心室收缩同步性的影响

目的 运用组织多普勒显像技术测量右室不同部位起搏的心脏超声参数,以评价右室不同部位起搏对左室收缩同步性的影响.方法 连续人组69例拟行起搏器植入术的患者,术前随机分为A组E36例,右室流出道起搏(right ventricular outflow tract pacing,RVOT)]及B组[33例,右室心尖起搏(right ventricular apexpacing,RVA)],分别于术前及术后3个月进行超声心动图检查,测量左室12节段收缩达峰时间(Ts)及收缩峰速度(Vs),计算12节段Ts标准差(Ts-SD)及Vs平均值(Vs-M).结果 A组和B组各有1例患者随访时因非起搏心律而剔除,共获得67例患者的组织多普勒图像进行脱机分析.术前两组左室收缩同步性差异无统计学意义,术后RVOT起搏组(A组)左室收缩同步性优于RVA起搏组(B组),差异有统计学意义[Ts-SD(23.63±2.32)ms对(31.54±2.93)ms,P=0.0387],对基础状态下Ts SD≥32.6 ms者进行亚组分析(A2组和B2组)RVOT起搏后Ts-SD显著小于术前[(28.55±16.93)ms对(48.19±9.26)ms,P=0.0045],而RVA起搏前后Ts-SD差异则无统计学意义,两亚组术后比较RVOT起搏亚组(A2组)Ts-SD显著小于RVA起搏亚组(B2组)r(28.55±16.93)ms对(38.19±18.34)ms,P=0.0290].结论 RVOT起搏对于左室收缩同步性影响小于RVA起搏,术前同步性较差者选择RVOT起搏能显著改善左室收缩同步性.     

超声三维斑点追踪评价不同心脏起搏方式对健康犬左心室功能的影响

目的 探讨超声三维斑点追踪成像技术评价不同心室位点心脏起搏对健康犬左室壁机械同步性和左室功能的影响.方法 分别采集10只健康开胸比格犬基础状态和右室心尖、左室心尖、左室侧壁起搏状态一个完整心动周期的左心室全容积实时图像;同步记录左室压力时间变化曲线并获取左室射血压力和收缩期压力最大上升速率.用超声三维斑点追踪分析软件分别提取不同状态左室壁径向三维应变图、左室壁径向三维峰值应变和左室收缩末期容积、舒张末期容积、射血分数、每搏输出量、心输出量.定性观察并比较不同状态左室壁各节段心肌的径向三维应变同步性.对定量参数进行配对t检验、卡方检验和直线相关分析.结果 ①左室心尖或侧壁起搏状态左室壁各节段心肌的径向三维应变不同步程度较右室心尖起搏状态明显.②左室心尖或侧壁起搏状态左室壁径向三维峰值应变显著减低的心肌节段数多于右室心尖起搏状态(9/16 对 2/16,P<0.05).③左室心尖或侧壁起搏状态左室壁整体径向三维峰值应变和左室每搏输出量、射血分数、心输出量均低于右室心尖起搏状态(P<0.05).④不同状态左室壁整体径向三维峰值应变分别与左室每搏输出量、射血分数、心输出量呈线性正相关(r=0.781～0.984,P<0.05).结论 左室心尖或侧壁起搏对健康犬左室壁机械同步性和左室功能的损害超过右心室心尖起搏.     

起搏位点对左心室收缩模式及功能的影响

目的 分析右室不同位点起搏状态下左室收缩模式及功能的改变,探讨生理性起搏模式的超声评价方法.方法 选择因阵发性室上性心动过速行射频消融的无器质性心脏病患者26例,于消融成功后,置入起搏导管,按照随机顺序分别起搏右房(AAI)、右室心尖部(VVI-RVA)、右室流出道(VVI-RVOT)、右室间隔部(VVI-IVS).测量各起搏状态下:①左室收缩功能参数,包括左室扭转角度(Twist)、主动脉瓣口血流速度—时间积分(VTIAo)、左室整体纵向应变(Gε);②左室收缩模式参数,包括左室各节段收缩期纵向应变峰值(Sε)、标化纵向应变达峰时间(TPε),分别计算不同层面、不同室壁Sε、TPε值,并用曲线图分别显示Sε、TPε在不同层面及不同室壁同的分布规律,分析不同室壁Sε、TPε的相关性.结果 与AAI组比较,右心室3个位点起搏组的左室收缩期Twist、VTIAo、Gε绝对值均显著降低(P均＜0.01),其中右室3个位点起搏组的Gε绝对值差异有统计学意义,表现为VVI-RVOT＞VVI-IVS＞VVI-RVA(P＜0.05).与AAI组比较,右室3个位点起搏组的左心室各节段收缩期Sε、TPε的分布模式改变明显,以RVA组最为显著,而RVOT组及RVS组分布模式较接近.室壁Sε与TPε呈负相关(r=-0.51,P＜O.001).结论 与AAI起搏模式相比,右室起搏可导致左室收缩模式的改变及收缩功能的降低,其中以RVA起搏状态改变最为明显.左室纵向应变参数可用于评价不同位点起搏状态下左室收缩模式及功能改变.     

超声斑点跟踪显像评价房室顺序起搏患者左心室收缩功能

目的探讨超声斑点跟踪显像技术评价房室顺序起搏患者左心室收缩功能的价值。方法用超声斑点跟踪显像技术分别检测房室顺序起搏心房起搏心房感知抑制型(AAI)模式患者10例(A组)、房室顺序起搏双心腔起搏双心腔感知触发和抑制型(DDD)模式患者10例(B组)及正常对照10例(C组)的左心室16个节段的径向位移、速度及应变指标,并与常规超声心动图测量所得左心室射血分数(EF值)进行相关分析和比较。结果三组间左心室EF值、收缩期16节段径向位移峰值均数、径向速度峰值均数与径向应变峰值均数差异均无统计学意义(P>0.05)。B组与C组相比,径向位移峰值在左心室下壁基底段、间隔基底段及心尖段降低,径向应变峰值在下壁及间隔心尖段降低,差异有统计学意义(P<0.05)。A组与C组相比,左心室各个节段的径向位移、径向速度与径向应变峰值差异均无统计学意义(P>0.05)。结论房室顺序起搏DDD模式时,左心室下壁及间隔的基底段和心尖段收缩功能降低,AAI模式时左心室节段性收缩功能无明显改变。     

三维斑点追踪成像技术评估右心双腔间隔起搏对左心室功能的影响

目的 应用三维斑点追踪成像（3D-STI）评估右心双腔间隔起搏对左心室功能的影响。方法 对42例右心双腔间隔起搏患者（起搏器组）和37名健康志愿者（对照组）行3D-STI检查,于心尖四腔切面图像获得左心室总体纵向峰值应变（GLS）、总体周向峰值应变（GCS）、总体径向峰值应变（GRS）、总体面积峰值应变（GAS）及左心室总体拧转（GTw）和左心室整体扭转（GTs）值。比较2组间三维应变参数,并分析GTw、GTs与GLS、GCS、GAS及GRS的相关性。结果 与对照组相比,起搏器组左心室GLS、GCS、GAS、GRS及GTs均明显减低（P均<0.05）;2组间GTw差异无统计学意义（P>0.05）。对照组GTs与GCS和GRS呈正相关（r=0.45、0.40;P均<0.05）,与GAS、GLS无相关性（P均>0.05）;GTw与GLS、GCS、GAS、GRS均无相关（P均>0.05）。起搏器组GTw、GTs与GLS、GCS、GAS、GRS均无相关（P均>0.05）。结论 右心双腔间隔起搏可损害左心室心肌形变能力,致左心室整体收缩功能隐匿性减低。     

Transarterial Permanent Pacing of the Left Ventricle

Clinical evaluation of a 64-year-old male patient with a permanent pacemaker showed a right bundle branch block in his ECG that led to the suspicion of catheter misplacement. A two-dimensional echocardiogram and bilateral venogram demonstrated that the pacemaker lead was not in the venous system and that its course was from the axillary artery to the left ventricle passing through the aortic valve. Thirty-three days after implant, replacement of the pacemaker lead through the venous system to stimulate the right ventricular endocardium was performed. At 7 month follow-up the patient has had no complication from his previous arterial pacemaker implantation.     

Feasibility Of Temporary Biventricular Pacing In Patients With Reduced Left Ventricular Function After Coronary Artery Bypass Grafting

Background and Methods: Biventricular pacing improves hemodynamics after weaning from cardiopulmonary bypass in patients with severely reduced left ventricular (LV) function undergoing coronary artery bypass grafting (CABG). We examined the feasibility of temporary biventricular pacing for 96 hours postoperatively. Unipolar epicardial wires were placed on the roof of the right atrium (RA), the right ventricular (RV) outflow tract, and the LV free lateral wall and connected to an external pacing device in 51 patients (mean LV ejection fraction 35 ± 4%). Pacing and sensing thresholds, lead survival and incidence of pacemaker dysfunction were determined.
Results: Atrial and RV pacing thresholds increased significantly by the 4th postoperative day, from 1.6 ± 0.2 to 2.5 ± 0.3 V at 0.5 ms (P = 0.03) at the RA, 1.4 ± 0.3 V to 2.7 ± 0.4 mV (P = 0.01) at the RV, and 1.9 ± 0.6 V to 2.9 ± 0.7 mV (P = 0.3) at the LV, while sensing thresholds decreased from 2.0 ± 0.2 to 1.7 ± 0.2 mV (P = 0.18) at the RA, 7.2 ± 0.8 to 5.1 ± 0.7 mV (P = 0.05) at the RV, and 9.4 ± 1.3 to 5.5 ± 1.1 mV (P = 0.02) at the LV. The cumulative overall incidence of lead failure was 24% by the 4th postoperative day, and was similar at the RV and LV. We observed no ventricular proarrhythmia due to pacing or temporary pacemaker malfunction.
Conclusions: Biventricular pacing after CABG using a standard external pacing system was feasible and safe.     

Implantation of left ventricular leads using a telescopic catheter system

BACKGROUND: Implantation procedures for cardiac resynchronization therapy (CRT) remain challenging with regard to coronary sinus (CS) cannulation and left ventricular (LV) lead positioning. Technologic advances in catheter design may facilitate CS cannulation and LV lead placement. AIMS: To evaluate two different telescoping dual-catheter systems, RAPIDO Guiding Catheter System (Group R) and RAPIDO ADVANCE Guiding Catheter System (Group A) (Guidant Inc., St. Paul, MN, USA), during implantation of a CRT device. METHODS: Seventy-four consecutive patients randomly received a CRT device using the R or A system. RESULTS: An LV lead was successfully implanted in 74 patients (100%). (1) Median times for CS cannulation in groups R and A were 0.3 minutes (range from 0.05 to 14 minutes) and 0.5 minutes (range from 0.05 to 9 minutes), respectively (P = NS). (2) Median times for LV lead placement were 8 minutes (range from 0.8 to 100 minutes) and 3.5 minutes (range from 0.25 to 30 minutes), respectively, for groups R and A (P = 0.032). (3) Median total fluoroscopy times were 12.33 minutes (range from 5 to 70 minutes) and 14.33 minutes (range from 6 to 53 minutes) for groups R and A, respectively (P = NS). (4) Median procedural times for CRT implantation were 80 minutes (range from 40 to 200 minutes) and 75 minutes (range from 45 to 180 minutes) (P = NS) in groups R and A, respectively. There were no major complications. CONCLUSION: CS cannulation and LV lead placement with a telescopic dual-catheter system is a safe and feasible approach that may reduce fluoroscopy and overall CRT implantation times. Our observations suggest that the RAPIDO ADVANCE System is faster than the RAPIDO System in terms of median time for LV lead positioning.     

Long-Term Experience with a Preshaped Left Ventricular Pacing Lead

OLLITRAULT, J., et al. : Long-Term Experience with a Preshaped Left Ventricular Pacing Lead. This study describes a long-term experience with a new LV pacing lead. The study population consisted of 62 patients (85% men,   71 ± 10   years old) with advanced dilated cardiomyopathy, in NYHA Class III or IV despite optimal drug therapy, and a QRS duration >150 ms. Patients in sinus rhythm were implanted with a triple chamber pacemaker to maintain atrioventricular synchrony. A dual chamber pacemaker was implanted in patients in atrial fibrillation for biventricular pacing only. A clinical evaluation and interrogation of the resynchronization pacemaker were performed at implant, at 1 week (W1), one (M1), four (M4), and seven (M7) months after implantation. A longer follow-up (2 years) is available for patients implanted at the authors institution. LV measurements were pacing threshold at 0.5-ms pulse duration and pacing impedance. R wave amplitude (mV) was measured at the time of implantation only. The system was successfully implanted in 86% of patients with the latest design of the lead. Mean R wave amplitude at implant was   15 ± 7 mV   and mean pacing impedance was   1054 ± 254 Ω   . Between implant   (n = 38)   and M7   (n = 15)   , pacing threshold rose from   0.73 ± 0.54   to   1.57 ± 0.60 V (P < 0.001)   . In conclusion, the situs lead was successfully implanted in a high percentage of patients. In addition, low pacing threshold and high impedance measured during follow-up are consistent with a low pacing current drain, ensuring a durable pulse generator longevity. (PACE 2003; 26[Pt. II]:185–188)     

Balloon‐Facilitated Delivery of a Left Ventricular Pacing Lead

While modern implant tools have contributed greatly to the success of cardiac resynchronization therapy, technical challenges remain. A common problem is the inability to advance left ventricular pacing leads into branch veins that are tortuous or arise at steep angles. In these cases, advancement of the lead causes it to buckle and prolapse into the coronary sinus or great cardiac vein. Lead prolapsed can be avoided by employing a balloon to temporarily obstruct the coronary sinus or great cardiac vein just upstream from the branch vein. The balloon redirects the force of advancement laterally into the branch vein, facilitating delivery. (PACE 2013; 36:e31–e34)     

Single Site Left Ventricular Pacing induced Dyssynchrony and Cardiomyopathy

Single site left ventricular (LV) pacing in the absence of intrinsic ventricular activity can be as detrimental to LV function as right ventricular apical pacing. This report describes a patient with complete heart block who developed significant dyssynchrony and cardiomyopathy secondary to single site lateral LV pacing. The process was reversed by placement of a second anterior LV lead. (PACE 2013; 36:e35–e37)     

Seven Years of Left Ventricular Pacing Due to Malposition of Pacing Electrode

The case report is presented of a patient in whom an uncomplicated left ventricular transvenous pacing produced right bundle branch block (RBBB). A diagnostic echocardiography, confirmed by cine cardiovascular computed tomography, showed that there was no rupture of the right ventricle and diagnosed a left ventricular pacing, due to malposition of the pacing electrode. The patient was treated with aspirin and dipyridamole during the last 6 years of follow-up, without any complications, including 1 year of pacing, prior to admission.     

Abolition of Diaphragmatic Pacing by Nonsurgical Retraction of a Left Ventricular Lead

This report describes the nonsurgical elimination of intractable diaphragmatic stimulation by partial withdrawal of a left ventricular (LV) pacing lead (in the coronary venous system) with resultant preservation of LV pacing. The procedure entailed the use of a deflectable catheter in the right atrium for ensnaring the LV lead. At the 3-month follow-up, the absence of diaphragmatic stimulation was associated with a satisfactory LV pacing threshold and dramatic clinical improvement from effectual biventricular pacing.