Preferred left ventricular lead position for upgrade from right ventricular pacing to cardiac resynchronization therapy

Introduction

Cardiac resynchronization therapy (CRT) is well-established for treating symptomatic heart failure with electrical dyssynchrony. The left ventricular (LV) lead position is recommended at LV posterolateral to lateral sites in patients with left bundle branch block; however, its preferred region remains unclear in patients being upgraded from right ventricular (RV) apical pacing to CRT. This study aimed to identify the preferred LV lead position for upgrading conventional RV apical pacing to CRT.

Methods

We used electrode catheters positioned at the RV apex and LV anterolateral and posterolateral sites via the coronary sinus (CS) branches to measure the ratio of activation time to QRS duration from the RV apex to the LV anterolateral and posterolateral sites during RV apical pacing. Simultaneous biventricular pacing was performed at the RV apex and each LV site, and the differences in QRS duration and LV dP/dt_max from those of RV apical pacing were measured.

Results

Thirty-seven patients with anterolateral and posterolateral LV CS branches were included. During RV apical pacing, the average ratio of activation time to QRS duration was higher at the LV anterolateral site than at the LV posterolateral site (0.90 ± 0.06 vs. 0.71 ± 0.11, p < .001). The decreasing ratio of QRS duration and the increasing ratio of LV dP/dt_max were higher at the LV anterolateral site than at the posterolateral site (45.7 ± 18.0% vs. 32.0 ± 17.6%, p < .001; 12.7 ± 2.9% vs. 3.7 ± 8.2%, p < .001, respectively) during biventricular pacing compared with RV apical pacing.

Conclusion

The LV anterolateral site is the preferred LV lead position in patients being upgraded from conventional RV apical pacing to CRT.     

High-amplitude left ventricular pacing in cardiac resynchronization therapy: an alternative way to increase response rate in non-responders

Purpose

This study compared patients who underwent cardiac resynchronization therapy (CRT) by high-amplitude left ventricular (LV) pacing with those who underwent CRT by standard LV pacing.

Methods

We included 32 CRT patients with ejection fraction (EF) ≤35%, QRS time ≥120 ms, and New York Heart Association (NYHA) class III/IV symptoms of heart failure despite optimal medical treatment. These patients were evaluated clinically and echocardiographically before, three and six months after CRT. At the 3^rd month, the LV pulse amplitude value was set high at 5 volt for 16 patients [high-amplitude Group (HAG)], while for the other 16 patients, it was reduced to at least twice the threshold value at ≤2.5 volt [low-amplitude group (LAG)].

Results

Clinical and echocardiographic response rates of HAG and LAG after CRT were similar in the 3^rd and 6^th month. In both groups, increase in LVEF and decrease in LV ESV in the 3^rd and 6^th month were statistically significant compared to those before CRT, and NYHA class and end-diastolic volume (EDV) was significantly reduced in the 6^th month compared to those before CRT. However, NHYA class and EDV continued to reduce significantly in HAG from the 3^rd to the 6^th month (P<0.05), while the decrease in LAG was not significant (P>0.05). The rate of mitral regurgitation (MR) was reduced significantly in HAG in the 6^th month compared to that before CRT, while the decrease in LAG was not significant (P<0.05; P>0.05 respectively).

Conclusions

CRT by high-amplitude LV pacing was more effective according to clinical and echocardiographic evaluations. It should be considered as an alternative in non-responsive patients.KEYWORDS : Heart failure (HF), cardiac resynchronization therapy (CRT), echocardiography, high-amplitude left ventricular pacing     

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.     

Cardiac resynchronization therapy: predictive factors of unsuccessful left ventricular lead implant.

AIMS: Cardiac resynchronization therapy is an established therapy for advanced heart failure. However, coronary sinus access and pacing is not achieved in about 5-10% of patients. The aim of this study was to identify predictive factors for failure of left ventricular (LV) lead transvenous implant. METHODS AND RESULTS: We evaluated 212 consecutive patients who received a cardiac resynchronization system. In 26 patients (12.3%), the attempt to pace the LV was unsuccessful. At univariate analysis, in patients with an unsuccessful implant a higher proportion of permanent atrial fibrillation (AF), valvular heart disease, and previous heart surgery were observed. Anteroposterior, longitudinal, and transversal left atrium diameters (LAD) were also larger among patients with an unsuccessful implant. The anteroposterior LAD (APLAD) with an optimal value to predict implant failure was 48.5 mm. At logistic regression analysis, the presence of permanent AF and APLAD were independent predictors of failed implant (OR 7.7, 95% CI 2.5-23.9, P=0.002 and OR 11.7, 95% CI 3.1-37.6, P<0.001, respectively). CONCLUSION: The presence of permanent AF and APLAD are factors that predict unsuccessful pacing from the LV.     

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.     

左室电极起搏位置与心脏再同步化治疗的疗效

目的探讨左室电极在左室游离壁不同位置起搏对慢性心力衰竭(简称心衰)心脏再同步化治疗(CRT)患者远期疗效的影响。方法 110例扩张型心肌病或高血压病合并慢性左心衰患者均符合CRT植入指征而接受CRT术,术后根据后前位和左前斜位的胸部X线影像,左室电极导线植入部位分为前壁、侧壁、后壁和后基底部。术后12个月,分别查心脏超声、心电图等,分析心功能、心电图QRS波时限和左室射血分数(LVEF)及左室容积变化。以心功能(NYHA)分级至少改善1级或LVEF升高25%以上定义为有效。结果由于患者心脏静脉变异和组织超声多普勒检查结果,左室电极导线分别被植入前壁4例、侧壁68例和后壁37例、后基底部1例。术后3例因心功能恶化死亡,2例发生猝死,1例术后第9天因肺部感染死亡。术后12个月,104例生存者中,有效91例,无效13例,总有效率87.5%。左室电极位于侧壁组的有效率(92.4%)明显高于后壁组(85.7%)(P<0.05)。前壁或后基底部的5例均无效。结论 CRT对慢性心衰患者有效,其疗效与左室电极起搏位置密切相关,左室侧壁或后壁是左室电极导线的理想起搏部位。     

Regression of mitral regurgitation after cardiac resynchronization therapy in an adult with preserved left ventricular function and right ventricular pacing.

We report the case of a 60-year-old patient with preserved ventricular function and no organic mitral leaflet disease implanted with a dual-chamber pacemaker. Right ventricular pacing induced a major ventricular dyssynchrony, a severe mitral regurgitation, and symptoms of congestive heart failure. Upgrading to a biventricular device was associated with a decrease in the symptoms, the ventricular dyssynchrony, and the mitral regurgitation.     

Relation of right ventricular pacing in tetralogy of Fallot to electrical resynchronization

Prolonged QRS duration is a marker of increased sudden death risk in tetralogy of Fallot. Right ventricular pacing increased QRS duration in this population and could be counteracted with optimization of the atrioventricular interval in a subset of patients, potentially offering right ventricular resynchronization in patients with baseline right bundle branch block. Effective pacing therapy may require site-specific placement of pacing leads and precise pacemaker programming.     

Cardiac resynchronization therapy improves left ventricular remodeling and function compared with right ventricular pacing in patients with atrioventricular block

Right ventricular pacing (RVP) exerts a detrimental effect on left ventricular (LV) remodeling. In patients with atrioventricular block (AVB) that require ventricular pacing, the effect of biventricular pacing (BiVP) versus RVP on LV remodeling and function has not been comprehensively assessed in a meta-analysis. Electric databases MEDLINE and Cochrane Library were retrieved for randomized controlled trials (RCT) comparing RVP and BiVP in patients with AVB. Data on left ventricular ejection fraction (LVEF) and LV volumes were analyzed, stratified by different time points. Eleven RCTs were included in the final analysis. There was a significant reduction of LV end-systolic volume in BiVP compared with RVP, at 3, 6, 12, and 24 months follow-up (P?<?0.05 for all). BiVP was associated with a decreased LV end-diastolic volume in comparison to RVP at 3, 6, and 12 months. Compared with RVP, BiVP had a higher LVEF at all follow-up visits, with mean difference of 5.91, 3.29, 3.9, 6.66, and 8.69% at 3, 6, 12, 24, and beyond 24 months follow-up, respectively. The results were not significantly changed in sensitivity analysis after removal of studies with mean baseline LVEF <?50% or excluding studies with ablation-induced AVB. In patients with AVB and bradycardia that require ventricular pacing, BiVP is superior to RVP in improving LV remodeling and function.     

Left ventricular resynchronization predicted by individual performance of right and left univentricular pacing: A study on the impact of sequential biventricular pacing on ventricular dyssynchrony

BACKGROUND: There is increasing evidence that improvement in left ventricular (LV) mechanical dyssynchrony is correlated with LV functional recovery in patients undergoing cardiac resynchronization therapy (CRT). Recent studies have suggested that sequential biventricular pacing may be important for further optimizing parameters of ventricular dyssynchrony. OBJECTIVE: The purpose of this study was to evaluate the acute effect of varying sequential biventricular pacing settings on echocardiographic parameters of ventricular dyssynchrony and to identify predictors of the optimal setting. METHODS: Twenty-nine patients referred for CRT were evaluated with standard echocardiography and tissue Doppler imaging before and after implantation. Indices of interventricular and intraventricular dyssynchrony were assessed for trends during simultaneous and sequential biventricular pacing. RESULTS: Twelve patients (41%) demonstrated linear trends of decreasing systolic dyssynchrony index with increasing LV preactivation. The mean additional decrease in dyssynchrony index at the optimized setting compared with simultaneous biventricular pacing was 26% (P <.04). Twenty-two patients (76%) demonstrated linear trends to decreasing interventricular dyssynchrony with increasing LV preactivation. The trends were strongly correlated with the magnitude of difference of the respective dyssynchrony measures in right ventricular only and LV only univentricular pacing. A significantly, superior capacity of LV only pacing for ventricular resynchronization was found in this subgroup of patients. CONCLUSION: In patients undergoing CRT, differences in the performance of univentricular pacing are associated with linear trends in ventricular dyssynchrony parameters in sequential biventricular pacing. Quantitative differences in LV univentricular pacing impact on the capacity of biventricular pacing to correct ventricular dyssynchrony.     

Successful percutaneous extraction of an inadvertently placed left ventricular pacing lead.

A 74-year-old patient was referred for a rapidly increasing pacing threshold 9 months after DDD pacemaker implantation because of symptomatic total atrioventricular (AV) block. She had a history of hypertension, diabetes with micro-angiopathy and a recent transient ischaemic attack. The paced electrocardiogram on admission had a right bundle branch block pattern and 3-dimensional transoesophageal echocardiography demonstrated passage of the lead through an atrial septal defect with a left ventricular position in addition to moderate atherosclerosis of the ascending aorta. No thrombus could be detected on the lead. Percutaneous extraction is usually not recommended because of the risk of mobilization of thrombus material. However, the risk of stroke during removal using cardiopulmonary bypass in this patient was considerably increased because of the presence of multiple independent risk factors. Therefore, percutaneous extraction using a locking device was selected and performed without complications: follow-up was uneventful.     

Permanent His-bundle pacing as an alternative to biventricular pacing for cardiac resynchronization therapy: A multicenter experience

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Relation of left ventricular lead placement in cardiac resynchronization therapy to left ventricular reverse remodeling and to diastolic dyssynchrony

The effects of left ventricular (LV) lead placement for cardiac resynchronization therapy (CRT) on LV remodeling and dyssynchrony are not well defined. Sixty-one patients (age 60 +/- 11 years, 76% men) were evaluated by echocardiography before and 4 +/- 2 months after CRT and grouped by the LV lead placement (lateral, posterolateral, or anterolateral). Echocardiographic measurements included LV volumes and LV ejection fraction. Tissue Doppler imaging was used to assess for inter- and intraventricular systolic and diastolic dyssynchrony. Analysis of variance was used to determine the effect of the LV lead placement on echocardiographic variables after CRT. The LV lead was placed in a lateral cardiac vein in 33 patients (54%), posterolateral in 15 (25%), and anterior in 13 (21%). Lateral LV lead placement was associated with significantly smaller LV volumes compared with the posterolateral lead placement (p <0.01). Diastolic dyssynchrony improved significantly with lateral lead placement compared with the anterior lead location (p <0.05). Improvement in LV ejection fraction and inter- and intraventricular systolic dyssynchrony was similar among the 3 groups. In conclusion, in patients undergoing CRT, a lateral lead location resulted in greater reverse LV remodeling and improved diastolic dyssynchrony compared with other lead placement locations.