心力衰竭再同步治疗中小切口心外膜左心室电极置入的补救技术

目的 探讨小切口心外膜左心室电极置入行心脏再同步化治疗.方法 6例心力衰竭患者拟行心脏再同步化治疗,冠状窦途径失败后采用小切口心外膜置入左心室电极,同时经静脉置入右心房、右心室电极.术后随访1年,评价心功能和左心室电极参数.结果 经小切口心外膜途径,所有患者均成功将左心室电极置入到理想部位.无术中并发症,无住院期间死亡,无膈肌刺激征.术中,左心室起搏阈值为(1.2±0.5)V;术后12个月,左心室起搏阈值为(1.1±0.4)V.12个月随访时,6 min步行[(327±77)m比(267±68)m,P=0.001]明显增加,纽约心功能分级明显改善,左室射血分数明显增加[(26.1±6.0)%比(38.2±4.7)%,P:0.004],左心室舒张末期内径明显减少[(72.2±6.8)mnl比(84.1±7.2)mm,P=0.001].结论 小切口心外膜置入左心室电极安全、有效,可以作为经冠状窦途径置人失败患者的替代治疗.     

心脏再同步化治疗的特殊病例处理

目的观察心室再同步化治疗的特殊病例处理。方法对2例扩张型心肌病因冠状静脉畸形、左心室起搏电极不能达到理想起搏位置的患者采用心外科微创手术植入左心室心外膜起搏电极。结果2例患者三腔起搏器各起搏电极植入过程顺利，起搏器工作良好，起搏心率为80次/min。左心室收缩同步性均较术前改善。术后1周心功能均恢复至NYHA心功能分级Ⅲ级。无并发症。结论对经导管径路植入左心室电极失败的患者应用微创开胸左心室心外膜起搏电极植入进行心脏再同步化治疗是可行、安全且有效的。     

Isolation of the phrenic nerve to suppress diaphragmatic contraction induced by cardiac resynchronization

Left phrenic nerve stimulation is a well-known complication of cardiac resynchronization therapy (CRT). We report a case where electronic or anatomical repositioning of the left ventricular (LV) electrode (within the coronary sinus tributaries) was not feasible/effective. Surgical graft interpositioning was performed to successfully isolate the phrenic nerve from the previously implanted coronary sinus epicardial LV lead.     

Robotically assisted left ventricular epicardial lead implantation for biventricular pacing

OBJECTIVES: Ventricular resynchronization might be achieved in a minimally invasive fashion using a robotically assisted, direct left ventricular (LV) epicardial approach. BACKGROUND: Approximately 10% of patients undergoing biventricular pacemaker insertion have a failure of coronary sinus (CS) cannulation. Rescue therapy for these patients currently is limited to standard open surgical techniques. METHODS: Ten patients with congestive heart failure (New York Heart Association class 3.4 +/- 0.5) and a widened QRS complex (184 +/- 31 ms) underwent robotic LV lead placement after failed CS cannulation. Mean patient age was 71 +/- 12 years, LV ejection fraction (EF) was 12 +/- 6%, and LV end-diastolic diameter was 7.1 +/- 1.3 cm. Three patients had previous cardiac surgery, and five patients had a prior device implanted. RESULTS: Nineteen epicardial leads were successfully placed on the posterobasal surface of the LV. Intraoperative lead threshold was 1.0 +/- 0.5 V at 0.5 ms, R-wave was 18.6 +/- 8.6 mV, and impedance was 1,143 +/- 261 ohms at 0.5 V. Complications included an intraoperative LV injury and a postoperative pneumonia. Improvements in exercise tolerance (8 of 10 patients), EF (19 +/- 13%, p = 0.04), and QRS duration (152 +/- 21 ms, p = 0.006) have been noted at three to six months follow-up. Lead thresholds have remained unchanged (2.1 +/- 1.4 V at 0.5 ms, p = NS), and a significant drop in impedance (310 +/- 59 ohms, p < 0.001) has been measured. CONCLUSIONS: Robotic LV lead placement is an effective and novel technique which can be used for ventricular resynchronization therapy in patients with no other minimally invasive options for biventricular pacing.     

Comparison of chronic biventricular pacing between epicardial and endocardial left ventricular stimulation using Doppler tissue imaging in patients with heart failure.

In patients with a wide QRS, drug-resistant heart failure, and a coronary sinus that is unsuitable for transvenous biventricular pacing (BVP), a transseptal approach from the right to left atrium can allow endocardial left ventricular (LV) pacing (with permanent anticoagulant therapy) instead of epicardial pacing via the coronary sinus branches. We sought to compare the effects of endocardial pacing with those of epicardial LV pacing on regional LV electromechanical delay (EMD) and contractility. Twenty-three patients (68 +/- 8 years) with severe heart failure and QRS > or =130 ms received a pacemaker for BVP. Fifteen patients underwent epicardial LV pacing, and 8 underwent endocardial LV pacing because of an unsuitable coronary sinus. All LV leads were placed at the anterolateral LV wall. Six months after implant, echocardiography and Doppler tissue imaging were performed. LV wall velocities and regional EMDs (time interval between the onset of the QRS and local ventricular systolic motion) were calculated for the 4 LV walls and compared for each patient between right ventricular (RV) and BVP. The amplitude of regional LV contractility was also assessed. Epicardial BVP reduced the septal wall EMD by 11% versus RV pacing (p = 0.05) and the lateral wall EMD by 41% versus RV pacing (p <0.01). With endocardial BVP, the septal and lateral EMDs were 21.3% and 54%, respectively (p <0.01, compared with epicardial BVP). The mitral time-velocity integral increased by 40% with endocardial BVP versus 2% with epicardial BVP (p <0.01). The amplitude of the lateral LV wall systolic motion increased by 14% with epicardial BVP versus 31% with endocardial BVP (p = 0.01). This resulted in a LV shortening fraction increase of 25% in patients with endocardial BVP (p = 0.05). However, all patients were clinically improved at the end of follow-up. Thus, in heart failure patients with BVP, endocardial BVP provides more homogenous intraventricular resynchronization than epicardial BVP and is associated with better LV filling and systolic performance.     

The coronary venous anatomy: a segmental approach to aid cardiac resynchronization therapy

The coronary sinus is the gateway for left ventricular (LV) epicardial lead placement for cardiac resynchronization therapy. The implanting electrophysiologist is usually challenged by a high degree of variability in the coronary venous anatomy, making it important to have a more consistent and uniform segmental approach to describe the coronary venous tree and its branches. Classifying the coronary sinus branches and tributaries by the segment of their location rather than by conventional anatomic names (i.e., middle cardiac vein, great cardiac vein, and so on), would provide more relevant anatomic and functional information at the time of LV lead placement. This would enable the implanting physician to proactively correlate the venous anatomy with the segmental wall motion abnormalities or dyssynchrony, as defined by echocardiography and other imaging modalities. The current viewpoint calls for a more systematic segmental approach for describing the coronary venous anatomy.     

Resynchronization with Left Ventricle Lead Placement Through the Foramen Ovale

Left ventricle (LV) lead placement in a coronary sinus branch for cardiac resynchronization therapy may fail because of anatomical variants, phrenic nerve stimulation, and/or lead instability. We report a case of successful resynchronization from a lead inserted from the left subclavian vein and positioned through a patent foramen ovale (PFO). In conclusion, endocardial LV lead insertion through a PFO enables effective resynchronization delivery without the risks associated with a thoracotomy or atrial transseptal puncture. Copyright © 2009 Wiley Periodicals, Inc.     

Role of multislice computed tomography for preprocedural evaluation before revision of a chronically implanted transvenous left ventricular lead

The purpose of this study was to determine the feasibility of multislice computed tomography (MSCT) to assess the coronary sinus (CS) and its tributaries in patients who are undergoing cardiac resynchronization therapy and need a left ventricular (LV) lead revision. Preprocedural imaging modality, which may enable delineation of the cardiac venous anatomy in patients who need LV lead replacement, has not yet been evaluated. Ten patients with heart failure with previously implanted cardiac resynchronization therapy devices, who presented with worsening heart failure, were studied with MSCT and tissue Doppler imaging echocardiography before LV lead replacement. MSCT was performed to evaluate patency of the CS and coronary veins, and tissue Doppler imaging echocardiography assessed the region and the magnitude of mechanical dyssynchrony. An excellent concordance in the vein diameter, location, and status between MSCT and angiography was found. Apart from the need to perform a venoplasty in 1 patient and an unsuccessful lead explantation in another patient, all other anatomic issues were correctly predicted by MSCT. CS or vein occlusion were present in 4 patients, and in 3 of them surgical LV lead replacement was performed. Identification of a patent venous system enabling successful transvenous lead implantation was possible in 2 patients. Direct visualization of the proximity of the target vein to the phrenic nerve and the diaphragm guided lead selection and position in 4 patients. In conclusion, MSCT may be used to delineate the coronary venous anatomy in patients in whom LV lead replacement is needed to help strategize whether a transvenous or transthoracic approach may be preferred for LV lead revision.     

Transseptal endocardial left ventricular pacing: an alternative technique for coronary sinus lead placement in cardiac resynchronization therapy.

BACKGROUND: Coronary sinus (CS) lead placement for transvenous left ventricular (LV) pacing in cardiac resynchronization therapy (CRT) has a failure rate at implant and short-term follow-up between 10% and 15%. OBJECTIVE: The purpose of this study was to assess the feasibility of transseptal endocardial LV pacing in patients in whom transvenous CS lead placement had failed. METHODS: An atrial transseptal LV lead placement was attempted in 10 patients (six females, age 69.4 +/- 9.6 years), in whom CS lead placement for CRT had failed. After transseptal puncture and septal dilatation from the femoral route, the left atrium was cannulated with a combination of catheters and guide wires from the left or right subclavian vein. After advancement of this guide catheter into the LV, a standard bipolar screw-in lead could be implanted in the posterolateral wall. All patients were maintained on anticoagulant therapy with warfarin after implant. RESULTS: An LV lead could be successfully implanted in nine of the 10 patients. The stimulation threshold was 0.78 +/- 0.24 V, and the R-wave amplitude was 14.2 +/- 9.7 mV. At 2 months' follow-up, the stimulation threshold was 1.48 +/- 0.35 V with a 0.064 +/- 0.027 ms pulse width. There was no phrenic nerve stimulation observed in any of the patients. There were no thromboembolic complications at follow-up. CONCLUSIONS: LV transseptal endocardial lead implantation from the pectoral area is a feasible approach in patients with a failed CS approach and in whom epicardial surgical lead placement is not an option. Longer follow-up is warranted to determine the risk of thromboembolic complications.     

Variegated left ventricular electrical activation in response to a novel quadripolar electrode: Visualization by non-invasive electrocardiographic imaging

Improving response to cardiac resynchronization therapy (CRT) remains challenging. Appropriate candidates may be identified by the presence of left ventricular (LV) conduction delay. An additional determinant may be the electrical effect elicited by LV pacing, which may vary among and within individuals. However, this is little explored, reflecting the lack of means for both easily altering lead position in any individual patient and of rapidly assessing its electrical effects. However, the advent of both multipolar LV electrodes and non-invasive single-beat electroanatomic mapping potentially resolves these challenges. These were investigated here. Results confirmed wide variations in electrical responses to LV pacing. In any individual patient, different pacing configurations elicited different electrical effects. Conversely, any one stimulation vector produced different effects in different patients. Thus, the reaction of electrical substrate to LV pacing is inconsistent. This observation introduces an added level of complexity in the understanding CRT electrical action. Attention to this factor may influence response to electrical resynchronization therapy.     

心脏再同步治疗患者心脏静脉血流异常分析

目的研究心脏再同步治疗（CRT）患者心脏静脉系统血流异常情况,以便左心室电极导线植入。方法109例植入CRT患者,男性67例,女性42例,年龄46～84（61．8±14．2）岁,其中扩张性心肌病90例,高血压性心脏病15例,缺m性心肌病4例,心功能Ⅲ-Ⅳ级（NYHA分级）。通过采用后前位、左前斜和右前斜3种不同x线体位,分别经冠状静脉窦逆行灌注显像或经冠状动脉造影延迟顺行心脏静脉显像,观察心脏静脉系统血流异常的情况,总结心脏静脉系统解剖变异特点。结果心脏静脉系统造影显像提示37例（33．9％）植入CRT患者存在不同程度的心脏静脉系统血流异常,其中冠状静脉窦口或窦体异常者15例（13．8％）,心脏静脉分支异常者22例（20．1％）。经心脏静脉系统而完成CRT植入术的成功率为99％,荭心室电极导线脱位发生率为2％,未出现严重并发症病例。结论心脏静脉系统血流异常是心力衰竭患者比较常见的现象,绝大部分左心室电极导线植入均能经心脏静脉系统顺利完成。     

Does left ventricular dyssynchrony immediately after acute myocardial infarction result in left ventricular dilatation?

BACKGROUND: Reverse remodeling of the left ventricle (LV) is one of the advantageous mechanisms of cardiac resynchronization therapy (CRT). Substantial LV dyssynchrony seems mandatory for echocardiographic response to CRT. Conversely, LV dyssynchrony early after acute myocardial infarction may result in LV dilatation during follow-up. OBJECTIVE: The purpose of this study was to evaluate the relation between LV dyssynchrony early after acute myocardial infarction and the occurrence of long-term LV dilatation. METHODS: A total of 124 consecutive patients presenting with acute myocardial infarction who underwent primary percutaneous coronary intervention were included. Within 48 hours of intervention, two-dimensional echocardiography was performed to assess LV volumes, LV ejection fraction (LVEF), and wall motion score index (WMSI). LV dyssynchrony was quantified using color-coded tissue Doppler imaging (TDI). At 6-month follow-up, LV volumes and LVEF were reassessed. RESULTS: Patients with substantial LV dyssynchrony (> or =65 ms) at baseline (18%) had comparable baseline characteristics to patients without substantial LV dyssynchrony (82%), except for a higher prevalence of multivessel coronary artery disease (P = .019), higher WMSI (P = .042), and higher peak levels of creatine phosphokinase (P = .021). During 6 months of follow-up, 91% of the patients with substantial LV dyssynchrony at baseline developed LV remodeling, compared with 2% in the patients without substantial LV dyssynchrony. LV dyssynchrony at baseline was strongly related to the extent of long-term LV dilatation at 6 months of follow-up. CONCLUSION: Most patients with substantial LV dyssynchrony immediately after acute myocardial infarction develop LV dilatation during 6 months of follow-up.     

Coronary venoplasty during the implantation of the cardiac resynchronisation device--a case report

We describe a case of a 76-year-old patient with advanced block in the His-Purkjnie system, who underwent implantation of a cardioverter-defibrillator with cardiac resynchronisation therapy. Complete heart block occurred during the insertion of the coronary sinus cathether. The implantation of the left ventricular (LV) lead was impossible due to difficult anatomy of the coronary venous system. The right ventricular pacing caused the further prolongation of the QRS duration and exacerbation of heart failure symptoms. Thus, the LV lead was successfully implanted during the second procedure after the balloon venoplasty of the lateral cardiac vein. The biventricular pacing was successful during 4 months follow-up.     

速度向量成像技术在心力衰竭患者同步化治疗中的应用

目的研究速度向量成像技术(VVI)在指导心脏再同步化治疗(CRT)患者的筛选、左室电极的植入及评价CRT疗效的临床应用价值。方法药物难治性心力衰竭患者17例,年龄60±13岁,NYHA心功能分级Ⅲ或Ⅳ级,术前均经VVI评价左室内十二节段任2个节段收缩达峰时间的最大差值及标准差,并分析左室内收缩最延迟部位。行CRT治疗,将左室电极植入左心收缩最延迟部位相关的冠状静脉窦分支血管内。分别在术后第1,3个月进行随访。观察CRT治疗后患者心功能分级、超声心动图测定心功能指标,以及VVI评价同步性参数的变化。结果随访3个月,患者心功能分级提高I～II级,6min步行距离由309.77±76.05m增至402.06±87.09m(P<0.05),左室射血分数由0.32±0.04增加至0.42±0.07(P<0.01),二尖瓣返流减少。VVI结果显示室内不同步较术前有明显改善。结论VVI技术可用于评价心脏的同步化状态、指导CRT的治疗及评价疗效。     

Comparison of stimulation sites within left ventricular veins on the acute hemodynamic effects of cardiac resynchronization therapy

OBJECTIVES: The purpose of this study was to study the acute hemodynamic effect of left ventricular (LV) stimulation sites within a coronary vein. BACKGROUND: Access to LV stimulation sites for resynchronization therapy is achieved using specialized lead systems navigated through a coronary vein. The effects of stimulation in different coronary veins have been evaluated previously, but less is known about stimulation sites within a coronary vein. METHODS: Twenty-four patients (New York Heart Association functional class II-IV, age 59 +/- 10 years, ejection fraction 21 +/- 7%, QRS 166 +/- 30 ms) were enrolled in the study. A novel over-the-wire lead system was used to access an anterior or lateral coronary vein. At each lead location, a randomized stimulation protocol was executed. Hemodynamic responses were evaluated using LV dP/dtmax. RESULTS: The mean time to cannulate the coronary sinus and position the LV lead was 19 +/- 30 minutes and 17 +/- 18 minutes, respectively. Data from stimulation at two sites within a coronary vein were obtained in 19 patients (anterior vein 11; lateral vein 8). Of these patients, 14 (anterior vein 9; lateral vein 5) showed large improvement in dP/dtmax (22%-25% in anterior vein, 37%-40% in lateral vein). Overall, there were no group differences in hemodynamic effects among different stimulation sites within a coronary vein, although significant variability among sites was observed in individuals. CONCLUSIONS: Resynchronization therapy through a coronary vein improves acute hemodynamic function of heart failure patients with LV conduction disorder. There were no significant differences between basal and apical pacing sites for this group.     

Epicardial versus transvenous left ventricular lead placement in patients receiving cardiac resynchronization therapy: results from a randomized prospective study

BACKGROUND: The aim of this prospective study was to determine the differences in left ventricular (LV) lead positioning for cardiac resynchronization therapy (CRT): comparing a percutaneous transvenous approach via the coronary sinus versus epimyocardial placement via a left lateral mini-thoracotomy. METHODS: Eighty consecutive patients with symptomatic left ventricular dysfunction and an indication for CRT were randomized to receive either a transvenous (n = 40) or epicardial (n = 40) LV-lead placement. Postoperative follow-up included assessment of NYHA functional class, ECG and echocardiography. RESULTS: The transvenous group had a shorter ICU stay (0.66 vs. 3.8 days) and shorter ventilation times (0.34 vs. 3.2 h). The epicardial group had less exposure to radiation (7.4 vs. 23 min) and required less use of contrast medium (3.24 vs. 61 ml). At 6 months follow-up, no major differences in LV-lead parameters (threshold, sensing, and impedance) were observed. CONCLUSION: Both epicardial and transvenous LV-lead placement for CRT therapy are safe and effective. The transvenous approach is less invasive and should be considered the standard procedure for patients without renal insufficiency. However, in a case of difficult coronary venous anatomy with the inability to position the lead as desired, epicardial LV-lead placement remains an alternative option.     

TEE-guided left ventricular epicardial pacing lead placement for cardiac resynchronization therapy

Biventricular pacing has demonstrated improvement in cardiac functions in treating congestive cardiac failure patients. Recent trials have proven the clinical and functional benefits of cardiac resynchronization therapy in severe heart failure and intraventricular cardiac delays, mainly left bundle branch block. Biventricular pacing improves the exercise tolerance, quality of life, systolic heart function, reduces hospitalization and slows progression of the disease. A 54-year-old lady, a known case of dilated cardiomyopathy, was on biventricular pacing since 2 years. She presented in emergency with sudden deterioration of dyspnea to NYHA class III/IV. When investigated, the coronary sinus lead was found displaced; thus, left ventricle (LV) was not getting paced. After multiple failures to reposition the coronary sinus lead, it was decided to surgically place the epicardial lead for LV pacing under general anesthesia. Lateral thoracotomy was done and LV pacing lead was placed at different sites with simultaneous monitoring of cardiac output (CO) and stroke volume (SV) by transesophageal echocardiography (TEE). Baseline CO and SV were 1.9 l/min and 19.48 ml respectively and increased at different sites of pacing at LV, the best CO and SV were 4.2 l/min and 42.39 ml respectively on lateral surface. Intraoperative TEE can calculate beat to beat stroke volume and thus CO and helps to choose optimal site for placement of epicardial pacing lead.     

Unusual cause for loss of left ventricular capture in patient with cardiac resynchronization due to tuberculous pericarditis

We report a case of 37-year-old man implanted with cardiac resynchronization therapy-defibrillator presented with persistent low-grade fever and sudden loss of left ventricular (LV) capture from coronary sinus lead after generator replacement. ¹⁸F-fluorodeoxyglucose positron emission tomography with computed tomography scan showed increased uptake at posterolateral region of the pericardium adjacent to the LV lead, suggestive of possible lead-related infection. Combined percutaneous and surgical lead extraction revealed purulent pericarditis and polymerase chain reaction testing confirmed tuberculous (TB) pericarditis. TB pericarditis is an unusual cause of loss of LV capture, but should be considered in countries where TB is still endemic.     

心脏再同步化治疗术中所遇问题及并发症的处理

目的介绍心脏再同步化治疗(CRT)手术中所遇的问题及并发症处理。方法回顾分析单中心CRT植入过程中所遇问题及并发症的发生与相应处理。结果共有4例患者出现问题或并发症,其中男3例、女1例。例1冠状静脉窦难以寻找,而改为右室双部位起搏;例2术中发生冠状静脉窦静脉夹层;例3术中突发急性左心衰竭,左室电极导线难以固定而留置经皮冠状动脉腔内成形术(PTCA)钢丝;例4左室电极导线置于心中静脉,在右房、右室电极植入时反复出现空气栓塞。结论 CRT术前应充分抗心力衰竭治疗,术中避免静脉夹层及空气栓塞,必要时右室双部位起搏,难以固定时留置PTCA钢丝于靶静脉内是可行的。     

Concurrent Epicardial Cardiac Resynchronization at Time of Complicated Biventricular Device Extraction: A Potentially Life-Saving Option

A 60-year-old man with cardiac resynchronization therapy defibrillator (CRT-D) lead endocarditis underwent transvenous lead extraction that was complicated by coronary sinus laceration and tamponade. Severe left ventricular dysfunction and unstable hemodynamic parameters persisted after emergent sternotomy, drainage, and repair. Reinstitution of cardiac resynchronization therapy with an epicardial device resulted in immediate hemodynamic improvement. Our case illustrates the potentially life-saving nature of single-stage extraction and reimplantation in resynchronization responders.