CRT治疗患者心室复极异质性指标的变化及不同起搏部位的影响

目的探讨心脏再同步化治疗患者心室复极异质性指标的变化以及不同部位起搏对心室复极异质性指标的影响。方法22例难治性心力衰竭患者,纽约心功能协会（NYHA）心功能分级Ⅲ～Ⅳ级,左心室射血分数（LVEF）≤35％,左心室舒张末内径（LVEDD）〉55mm,ORS波时限〉120ms,组织多普勒显像（TDI）证实心脏机械活动不同步,且经最优化药物治疗无效,行心脏再同步化治疗（CRT）后定期随访。以常规体表12导联心电图QT离散度及Tpeak-end间期以及Tpeak-end离散度作为心室复极异质性的指标。于CRT术前、术后1、3、6、12个月,分别在右室起搏、左室起搏、双室起搏三种不同起搏模式下测量心室复极异质性指标。结果QT离散度及Tpeak-end、Tpeak-end离散度在双室起搏时最小,左室起搏时最大,双室起搏与右室起搏之间没有统计学差异;CRT治疗后心室复极异质性指标明显改善,并且随着时间延长．心室复极异质性指标逐渐变小。结论CRT治疗可以明显改善心室复极异质性,右室起搏下心室复极异质性指标与双室起搏相似,但左室起搏则明显增加心室复极异质性指标。     

双心室再同步化起搏治疗充血性心力衰竭患者的效果与护理

目的探讨双心室再同步化起搏治疗充血性心力衰竭患者的疗效及护理。方法比较63例充血性心力衰竭患者术前及行双心室再同步化起搏治疗术后的心功能NYHA分级、心电图QRs时限、左心室射血分数LVEF以及运动耐量6min步行距离,并对患者的护理措施进行总结。结果患者治疗后6个月NYHA从术前（3．40±0．50）级改善为术后（2．30±0．60）级,QRS时限从（144．68±16．40）1]ms降至（100．02±14．76）ms,LVEF（％）从（33．18±5．60）提高至（41．8±7．45）,6min步行距离从（305．40±30．30）m提高至（406．20±70．50）m,差异均有统计学意义（t=11．18,4．562,6．728,10．426;P〈0．01）;术后跟踪随访3—24个月,无一例死亡。结论双心室再同步化起搏是治疗充血性心力衰竭患者的一种有效治疗方法,能明显改善患者心脏功能及生活质量。做好术前心理护理、术中心电监测、术后观察和预防并发症的发生以及重视出院后跟踪随访等都是取得较佳疗效的重要保证。     

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。     

心室不同部位起搏的急性血流动力学效应

目的 在无束支阻滞、心功能Ⅰ～Ⅱ级患者中,比较5种不同起搏模式的血流动力学效应及其对QRS宽度的影响。方法 在安置永久起搏器前分别行右室心尖部、右室流出道、右室双部位、左室基底部、双室同步起搏(ⅤⅥ,60～80次/min)5min,测定心脏指数(CI)、平均肺动脉压(mPAP)、肺毛细血管嵌顿压(PCWP)以及QRS宽度。结果(1)与右室心尖部起搏相比,右室流出道、左室基底部、右室双部位、双室同步起搏CI显著增加、PCWP明显降低(P均<0.01);(2)右室双部位、双室同步起搏较右室流出道、左室基底部起搏的CI增高而PCWP降低(P均<0.05);(3)右室双部位与双室同步起搏、右室流出道与左室基底部起搏间CI和PCWP无显著差异;(4)右室流出道、右室双部位、双室同步起搏的QRS宽度较右室心尖部起搏时显著缩短(P<0.01),而左室基底部起搏与右室心尖部起搏时无显著差异。结论 在无束支阻滞、心功能Ⅰ～Ⅱ级患者中,双部位起搏的效果明显优于单部位起搏;双部位起搏的QRS宽度也比单部位起搏明显缩短。在单部位起搏中,右室流出道和左室基底部起搏优于右室心尖部起搏,但左室基底部起搏的QRS宽度无明显缩短。     

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.     

生理性起搏与心室起搏对冠心病心律失常患者心脏耐力,生存质量及心功能的

目的：比较生理性起搏与心室起搏对缓慢型心律失常心脏耐力、生存质量及心功能的影响,方法：安置心室起搏器（ＶＶＩ型起搏器）３３８例,生理性起搏器８２例（其中双腔起搏器３２例）术后进行随访。结果：安置两种起捕器后患心脏耐力生存质量提高,心功能明显改善,晕阙症全部消失,尤以生理性起搏明显。结论：生理性起搏对患心脏耐力、生存质量及心功能的改善作用更好。     

电极接口血凝块致CRT-D起搏障碍1例

患者男，62岁因扩张型心肌病、第三度房事传导阻滞于2006-09-08行心脏再同步化治疗起搏器（carliac resynchronization therapy-defibrllator,CRT-D）植入术。起博器为美国圣尤达公司产品，型号为EPICTM HF V-350.手术顺利，历时5小时余。术后调试时发现左心室电极（冠状窭电极）无信号，遂改起搏馍式为左心室起搏，     

右心室起搏部位的国内外研究进展

自1958年第一例埋藏式起搏器问世以来,人工心脏起搏经历了50余年的发展,起搏器植入技术已成为治疗缓慢性心律失常最有效的手段。心脏起搏治疗已不仅局限在维持患者的基本心率及患者生存率,更重要的是提高患者生活质量,而这与起搏器激动心肌的顺序、心肌细胞重构程度、心脏电-机械活动的同步性以及血流动力学的稳定性密切相关。在心脏起搏方式、起搏参数一定时,起搏部位的选择是决定临床疗效的重要因素之一。人工心脏起搏器技术经过半个多世纪的发展已取得了长足发展,电生理专家们在积极探索更为接近生理状态的起搏部位。如何提高良好的安全性及可操作性,降低并发症的发生率,提高患者的生活质量,越来越成为当今起搏器发展过程中最需要关注的问题。     

双心室同步起搏治疗充血性心力衰竭

充血性心力衰竭是心内科常见的临床疾病，是造成患者丧失工作能力，具有较高病死率的严重疾患，每年有成千上万的患者死于心力衰竭。单美国每年有300多万人受到充血性心力衰竭的折磨。充血性心力衰竭的临床症状主要由于心腔扩大、心功能减退、心输出量减少造成，30％中重度心衰患者往往合并房室传导或心室内传导延迟（intraventricular conduction delay，IVCD），后者又进一步加重心力衰竭。目前心衰的主要治疗仍以药物为主，包括应用强心、利尿、ACEI及ARB类、β受体阻滞剂等综合治疗，以减轻心脏的前负荷、后负荷及增加心脏收缩力、减少心室重构。虽然应用药物可缓解症状，但仍有相当数景的患者．即使应用最佳的药物治疗．仍不能改变心功能衰竭进行性加重及改善预后。     

扩张型心肌病患者双心室起搏治疗的护理

双心室起搏可使左、右心室同步收缩，增加心输出量，改善心功能，纠正心衰。笔通过对7例行双心室起搏治疗扩张型心肌病患的护理，认为做好术前心理护理，术中密切配合，术后加强心电监护，密切观察起搏器的感知功能及起搏功能，对促进患康复、杜绝术后并发症起到重要作用。7例患双心室起搏治疗成功，心功能明显改善，生活可自理。     

Transseptal left ventricular endocardial pacing reduces dispersion of ventricular repolarization

Background: Cardiac resynchronization therapy (CRT) may be proarrhythmic in some patients. This may be due to the effect of left ventricular (LV) epicardial pacing on ventricular repolarization. The purpose of this study was to evaluate the effect of endocardial versus epicardial LV biventricular pacing on surface electrocardiogram (ECG) parameters that are known markers of arrhythmogenic repolarization. Methods: ECG markers of repolarization (QT dispersion, QTD; T peak to end, T_peak‐end; T_peak‐end dispersion, T_peak‐endD; QTc) were retrospectively measured before and after CRT in seven patients with transseptal LV endocardial leads (TS group), 28 matched patients with coronary sinus (CS) LV leads (CS group), and eight patients with surgical LV epicardial leads (SUR group). All ECGs were scanned and analyzed using digital callipers. Results: Compared to the CS group, the TS group CRT was associated with a significant postpacing reduction in QTD (?45.2 ± 35.6 vs ?4.3 ± 43.6 ms, P = 0.03) and T_peak‐end (?24.2 ± 22.1 vs 3.4 ± 26.7 ms, P = 0.02). There was a nonsignificant post‐CRT reduction in both T_peak‐endD (?11.3 ± 31.0 vs 2.4 ± 28.9 ms, P = 0.27) and QTc (?50.0 ± 46.4 vs 4.4 ± 70.2 ms, P = 0.06) in the TS versus the CS group. In contrast, there were no differences between the SUR and CS groups in terms of the effect of CRT on these repolarization parameters. Conclusions: CRT with (atrial transseptal) endocardial LV lead placement is associated with repolarization characteristics that are considered to be less arrhythmogenic than those generated by CS (epicardial) LV lead placement. Further work is needed to determine whether these changes translate to a reduction in proarrhythmia. (PACE 2011; 34:1258–1266)     

右心室起搏比例和不同部位起搏对老年患者心功能的影响

目的：探讨右心室起搏比例和不同部位起搏对老年患者心功能的影响。方法回顾性分析92例植入体内埋藏式双腔心脏起搏器（DDD）的老年患者的临床资料,根据术后1年起搏器程控仪获取的右心室起搏比例,将右心室起搏比例≥50%患者纳入A组,右心室起搏比例＜50%患者纳入B组,比较两组术前和术后1年彩色多普勒心脏超声的变化。同时,将A组分为右室心尖部（RVA）起搏者和右室间隔部（RVS）起搏者进行亚组分析。结果 A组术后1年左房内径（LAD）较术前增大,左室射血分数（LVEF）较术前和B组降低,差异均有统计学意义（t分别=2.43、4.20、6.37,P均＜0.05）;B组术后1年LAD、左室舒张末期内径（LVEDD）、LVEF和术前比较,差异均无统计学意义（t分别=0.73、0.78、1.16,P均＞0.05）。亚组分析结果显示两亚组术前LAD、LVEDD、LVEF比较,差异均无统计学意义（t分别=0.77、0.35、1.32,P均＞0.05）,两组术后LVEDD、LVEF比较,差异均有统计学意义（t分别=2.86、4.62,P均＜0.05）,RVS组术后LAD、LVEDD、LVEF与术前比较,差异均无统计学意义（t分别=1.45、0.14、0.48,P均＞0.05）;而RVA组术后LAD、LVEDD均较术前明显扩大,LVEF较术前明显下降（t分别=2.20、3.13、4.31,P均＜0.05）。结论老年患者中右室间隔部起搏与右室心尖部起搏相比更有利于保持患者心功能的稳定,但同时应尽量减少不必要的右心室起搏。     

The benefits of biventricular pacing in heart failure patients with narrow QRS, NYHA class II and right ventricular pacing

OBJECTIVE: To identify subgroups of heart failure patients who might benefit from biventricular pacing. BACKGROUND: Cardiac resynchronization therapy (CRT) improves the quality of life, New York Heart Association (NYHA) functional class, and exercise capacity and decreases hospitalizations for heart failure for patients who have severe heart failure and a wide QRS. It is unclear if other populations of heart failure patients would benefit from CRT. METHODS: One hundred forty-four consecutive heart failure patients who underwent CRT and completed 3 months of follow-up were reviewed. Demographic, echocardiographic, electrocardiographic, and clinical outcome data were analyzed to assess the relationship of functional class and QRS duration before device implantation to postimplant outcomes. RESULTS: There were 20, 88, and 36 patients in NYHA functional class II, III, and IV, respectively. Thirty-four patients had right ventricular pacing and another 29 patients had a QRS duration < or = 150 ms. Patients who were in NYHA functional class II at baseline had significant improvement in left ventricular ejection fraction and indices of left ventricular remodeling after CRT. Similar significant findings were seen in the subgroup with right ventricular pacing at baseline after CRT. However, in the subgroup with a narrow QRS duration, there were no significant changes in the indices of left ventricular remodeling or in the NYHA functional class and there was a significant increase in the QRS duration. For the study cohort as a whole, an improvement in NYHA functional class after CRT correlated with a significant decrease in adverse clinical outcomes. CONCLUSIONS: Heart failure patients who were in NYHA functional class II and those with right ventricular pacing appeared to benefit from CRT.     

Maximizing biventricular pacing in patients with rate‐controlled atrial fibrillation using ventricular sense response

In patients with atrial fibrillation (AF), cardiac resynchronization therapy (CRT) is challenging because the ventricular rate of conducted AF exceeds the biventricular pacing rate. In the current report, we present a patient who received a CRT device that was programmed to ventricular sense response (VSR) on with VVI 40 beats per minute to allow the AF to be paced as fusion beats. We found that the pacing configuration resulting in the narrowest QRS in this patient was VVI 40 with VSR biventricular fusion pacing during AF. VSR mode allows for CRT delivery without the need to artificially increase heart rate.     

Latency during left ventricular pacing from the lateral cardiac veins: a cause of ineffectual biventricular pacing

We report three patients with cardiomyopathy and pronounced stimulus to QRS latency during left ventricular (LV) pacing from an epicardial cardiac vein. Delayed LV activation during simultaneous biventricular pacing produced an electrocardiographic pattern dominated by right ventricular stimulation. Hemodynamic parameters improved immediately after advancing LV stimulation (in one patient) or pacing the LV only (in two patients) coupled with dramatic improvement of heart failure symptoms.     

Morphology of the RV electrogram during LV pacing is related to the hemodynamic effect in cardiac resynchronization therapy

Background: Biventricular (BiV) pacing and left ventricular (LV) pacing both improve LV function in patients with heart failure and LV dyssynchrony. We studied the hemodynamic effect of the atrioventricular (AV) interval and the associated changes in the right ventricular (RV) electrogram (EGM) during LV pacing and compared this with the hemodynamic effect of optimized sequential BiV pacing.
Methods: In 16 patients with New York Heart Association (NYHA) class II to IV, sinus rhythm with normal AV conduction, left bundle branch block (LBBB), QRS > 130 ms, and optimal medical therapy, the changes in RV EGM during LV pacing with varying AV intervals were studied. The hemodynamic effect associated with these changes was evaluated by invasive measurement of LVdP/dt_max and compared with the result of optimized sequential BiV pacing in the same patient.
Results: All patients showed electrocardiographic fusion during LV pacing. The morphology of the RV EGM showed changes in the RV activation that indicated a shift in the extent of fusion from LV pacing. These changes were associated with significant changes in LVdP/dt_max. Baseline LV dP/dt_max was 734 ± 177 mmHg/s, which increased to 927 ± 202 mmHg/s (P<0.0001) with optimized LV pacing and to 920 ± 209 mmHg/s (P<0.0001) with optimized sequential BiV pacing.
Conclusion: The RV EGM is a proper indicator for intrinsic activation over the right bundle during LV pacing and reveals the transition to fusion in the RV EGM that is associated with a decrease in LVdP/dt_max. The hemodynamic effect of optimized LV pacing is equal to optimized sequential BiV pacing.     

Electrocardiographic patterns during: pacing the great cardiac and middle cardiac veins

BACKGROUND: The electrocardiogram (ECG) patterns during pacing from the great cardiac vein (GCV) and the middle cardiac vein (MCV) are not well known. METHODS: We recorded 12-lead ECGs during GCV and MCV pacing in 26 patients undergoing implantation of a cardiac resynchronization device. The left ventricular (LV) lead was passed down the GCV (n = 19) or MCV (n = 7) prior to moving it to a lateral or posterolateral vein for permanent implantation. RESULTS AND CONCLUSIONS: Pacing within the GCV resulted in a left bundle branch block (LBBB) morphology with no or minimal R-wave in V(1) in 14 patients and a right bundle branch block (RBBB) pattern (R > S in lead V(1)) in four patients. In one patient, lead V1 during GCV pacing was isoelectric (R = S). A more distal pacing site in the GCV yielded a LBBB pattern in all the patients. All leads placed in the MCV resulted in a LBBB configuration. An ECG pattern with a RBBB pattern was invariably recorded during LV pacing in 125 consecutive outpatients with biventricular pacemakers and LV leads in the posterolatral and lateral coronary veins. Knowledge of the ECG patterns from various pacing sites in the coronary venous system may be helpful for troubleshooting all types of pacing systems, especially those where the coronary venous pacing site is unintentional.