Left Ventricular Lead Position Research Articles

Exploring QRS Area beyond Patient Selection in CRT-Can It Guide Left Ventricular Lead Placement?

Vectorcardiographic QRS area is a promising tool for patient selection and implantation guidance in cardiac resynchronization therapy (CRT). Research has mainly focused on the role of QRS area in patient selection for CRT. Recently, QRS area has been proposed as a tool to guide left ventricular lead placement in CRT. Theoretically, vector-based electrical information of ventricular fusion pacing, calculated from the basic 12-lead ECG, can give real-time insight into the extent of resynchronization at any LV lead position, as well as any selected electrode on the LV lead. The objective of this review is to provide an overview of the background of vectorcardiographic QRS area and its potential in optimizing LV lead location in order to optimize the benefits of CRT.

Left ventricular anterolateral site is the preferable left ventricular lead position for an upgrade to biventricular pacing

Abstract Background Cardiac resynchronization therapy (CRT) is a well-established treatment for symptomatic heart failure with electrical dyssynchrony. The LV lead position in patients with left bundle branch block is usually recommended at the LV posterolateral to the lateral site, which is the latest electrical activation site. In contrast, the preferable LV lead position in patients who plan to upgrade from conventional RV apical pacing to CRT remains unclear. Purpose This study aimed to identify the preferable LV lead position for upgrading to CRT from conventional RV apical pacing. Methods An electrophysiological study was performed on patients who underwent ablation for atrial fibrillation. The electrode catheters were positioned at the RV apex, LV anterolateral, and LV posterolateral sites via the coronary sinus branches. During RV apical pacing, the activation time from the RV apex to the LV anterolateral and posterolateral sites was measured, and the activation time ratio to QRS duration was calculated. Biventricular pacing from both the RV apex and LV anterolateral or LV posterolateral sites was performed, and the difference in QRS duration and LV dP/dt compared to only the RV apical pacing state was measured. Results We enrolled 37 patients who exhibited anterolateral and posterolateral LV coronary sinus branches. During RV apical pacing, the average activation time ratio to QRS duration was higher at the LV anterolateral site than at the LV posterolateral site (0.89±0.07 vs. 0.71±0.11, P <0.001). The shortening ratio of QRS duration during biventricular pacing compared to baseline RV apical pacing was greater at LV anterolateral site than at the LV posterolateral site (45.7±18.0% vs. 32.0±17.6%, P <0.001). The improvement ratio of LV dP/dt during biventricular pacing was also better from the LV anterolateral site than from the LV posterolateral site (12.7±8.9% vs. 3.7±8.2%, P <0.001). Conclusion LV lead position in patients who plan to upgrade to CRT from conventional RV apical pacing is preferably at the LV anterolateral site.

Targeted left ventricular lead positioning to the site of latest activation in cardiac resynchronization therapy: a systematic review and meta-analysis.

Several studies have evaluated the use of electrically- or imaging-guided left ventricular (LV) lead placement in cardiac resynchronization therapy (CRT) recipients. We aimed to assess evidence for a guided strategy that targets LV lead position to the site of latest LV activation. A systematic review and meta-analysis was performed for randomized controlled trials (RCTs) until March 2023 that evaluated electrically- or imaging-guided LV lead positioning on clinical and echocardiographic outcomes. The primary endpoint was a composite of all-cause mortality and heart failure hospitalization, and secondary endpoints were quality of life, 6-min walk test (6MWT), QRS duration, LV end-systolic volume, and LV ejection fraction. We included eight RCTs that comprised 1323 patients. Six RCTs compared guided strategy (n = 638) to routine (n = 468), and two RCTs compared different guiding strategies head-to-head: electrically- (n = 111) vs. imaging-guided (n = 106). Compared to routine, a guided strategy did not significantly reduce the risk of the primary endpoint after 12-24 (RR 0.83, 95% CI 0.52-1.33) months. A guided strategy was associated with slight improvement in 6MWT distance after 6 months of follow-up of absolute 18 (95% CI 6-30) m between groups, but not in remaining secondary endpoints. None of the secondary endpoints differed between the guided strategies. In this study, a CRT implantation strategy that targets the latest LV activation did not improve survival or reduce heart failure hospitalizations.

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

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. 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/dtmax from those of RV apical pacing were measured. 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/dtmax 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. The LV anterolateral site is the preferred LV lead position in patients being upgraded from conventional RV apical pacing to CRT.

The last shall be the first: the role of combined QLV- and CMR-determined electromechanical concordance in predicting optimal left ventricular stimulation site in cardiac resynchronisation therapy

Abstract Funding Acknowledgements Type of funding sources: None. Background/introduction Optimisation of cardiac resynchronisation therapy (CRT) response still represents a significant challenge to cardiac electrophysiology. In this regard, perhaps the area of greatest uncertainty revolves around optimal left ventricular lead (LVL) position and in particular whether this should be directed at areas of latest electrical or mechanical activation given the equivocal evidence on their precise relationship in heart failure (HF) patients. Furthermore, while echocardiography has demonstrated that LVL aimed at regions of greatest mechanical delay maximises CRT response, cardiac magnetic resonance (CMR) with its greater spatial resolution and tissue definition is yet to demonstrate a role in doing so. Purpose To retrospectively evaluate concordance between latest electrical and CMR-determined mechanical activation in a CRT population and its relationship with reverse remodeling. Methods This is a retrospective single center analysis of 104 CRT patients. All patients had CMR and echocardiography performed before implantation. During implantation, coronary sinus angiogram was performed and electrical delay (QLV time with RV-LV time greater than 80 ms) was mapped on all veins suitable for lead implantation and LVL was positioned in the region of latest electrical activation programming LVL cathode accordingly. LVL cathode position was thus assumed to represent the region of latest electrical delay. A post-hoc analysis was then conducted by means of CART-Tech® software providing radial strain and scar maps on a 36-segment anatomical model. Patients were then stratified based on concordance between LVL cathode position (using 3D heart models superimposed on 2D angiography images) and most mechanically delayed segments (either the three most delayed segments or adjacent ones) or non concordance (one or more segments between LVL cathode and three most mechanically delayed segments). Data from patient follow-up was collected with echocardiography at least 3 months after implant date. CRT response was expressed as reduction in end-systolic volume (ESV) greater than 15%. Results A preliminary analysis of the first 30 patients of our cohort was conducted. Electromechanical concordance and non-concordance were present in 24 and 6 patients, respectively. Baseline patient characteristics including demographics, comorbidities, HF aetiology, ECG and echocardiography features were comparable between groups except for scar burden, which was higher in the non-concordance group. Response to CRT was 80% in the concordant vs. 20% in the non-concordant group. Conclusions While a confounding effect of scar burden cannot be excluded, these preliminary data suggest that electromechanical concordance in LVL cathode placement may represent a predictor of optimal CRT response. The full scope of this study will be fully appreciated in the coming month on completion of analysis of the entire patient cohort.

Does targeted positioning of the left ventricular pacing lead towards the latest local electrical activation in cardiac resynchronization therapy reduce the incidence of death or hospitalization for heart failure?

Cardiac resynchronization therapy (CRT) improves symptoms, health-related quality of life and long-term survival in patients with systolic heart failure (HF) and shortens QRS duration. However, up to one third of patients attain no measurable clinical benefit from CRT. An important determinant of clinical response is optimal choice in left ventricular (LV) pacing site. Observational data have shown that achieving an LV lead position at a site of late electrical activation is associated with better clinical and echocardiographic outcomes compared to standard placement, but mapping-guided LV lead placement towards the site of latest electrical activation has never been investigated in a randomized controlled trial (RCT). The purpose of this study was to evaluate the effect of targeted positioning of the LV lead towards the latest electrically activated area. We hypothesize that this strategy is superior to standard LV lead placement. The DANISH-CRT trial is a national, double-blinded RCT (ClinicalTrials.gov NCT03280862). A total of 1,000 patients referred for a de novo CRT implantation or an upgrade to CRT from right ventricular pacing will be randomized 1:1 to receive conventional LV lead positioning preferably in a nonapical posterolateral branch of the coronary sinus (CS) (control group) or targeted positioning of the LV lead to the CS branch with the latest local electrical LV activation (intervention group). In the intervention group, late activation will be determined using electrical mapping of the CS. The primary endpoint is a composite of death and nonplanned HF hospitalization. Patients are followed for a minimum of 2 years and until 264 primary endpoints occurred. Analyses will be conducted according to the intention-to-treat principle. Enrollment for this trial began in March 2018, and per April 2023, a total of 823 patients have been included. Enrollment is expected to be complete by mid-2024. The DANISH-CRT trial will clarify whether mapping-guided positioning of the LV lead according to the latest local electrical activation in the CS is beneficial for patients in terms of reducing the composite endpoint of death or nonplanned hospitalization for heart failure. Results from this trial are expected to impact future guidelines on CRT. NCT03280862.

Association between left ventricular lead position and intrinsic QRS morphology with regard to clinical outcome in cardiac resynchronization therapy for heart failure.

Left ventricular (LV) lead position may be an important factor for delivering effective cardiac resynchronization therapy (CRT). We therefore aimed to evaluate the effects of LV lead position, stratified by native QRS morphology, regarding the clinical outcome. A total of 1295 CRT-implanted patients were retrospectively evaluated. LV lead position was classified as lateral, anterior, inferior, or apical, and was determined using the left and right anterior oblique X-ray views. Kaplan Meier and Cox regression were performed to evaluate the effects on all-cause mortality and heart failure hospitalization, and the potential interaction between LV lead position and native ECG morphologies. A total of 1295 patients were included. Patients were aged 69 ± 7 years, 20% were female, 46% received a CRT-Pacemaker (vs. CRT-Defibrillator), mean LVEF was 25% ± 7%, and median follow-up was 3.3 years [IQR 1.6-5-7 years]. Eight hundred and eighty-two patients (68%) had a lateral LV lead location, 207 (16%) anterior, 155 (12%) apical, and 51 (4%) inferior. Patients with lateral LV lead position had larger QRS reduction (-13 ± 27 ms vs. -3 ± 24 ms, p < .001). Non-lateral lead location was associated with a higher risk for all-cause mortality (HR 1.34 [1.09-1.67], p = .007) and heart failure hospitalization (HR 1.25 [1.03-1.52], p = .03). This association was strongest for patients with native left or right bundle branch block, and not significant for patients with prior paced QRS or nonspecific intraventricular conduction delay. In patients treated with CRT, non-lateral LV lead positions (including apical, anterior, and inferior positions) were associated with worse clinical outcome and less reduction of QRS duration. This association was strongest for patients with native LBBB or RBBB.

Minimally invasive epicardial left-ventricular lead implantation and simultaneous left atrial appendage closure.

Atrial fibrillation (AF) is common in patients with heart failure resulting in a high prevalence of AF in patients receiving Cardiac Resynchronization Therapy (CRT) implantation. In patients, unsuitable for transvenous left ventricular (LV)-lead implantation, epicardial LV-lead implantation represents a valuable alternative. Epicardial LV-lead placement can be achieved totally thoracoscopical or via minimally invasive left lateral thoracotomy. In patients with atrial fibrillation, concomitant left atrial appendage (LAA) clipping is feasible via the same access. Therefore, the aim of our study was the analysis of safety and efficacy of epicardial LV lead implantation and concomitant LAA clipping via minimally invasive left-lateral thoracotomy. Between December 2019 and March 2022, 8 patients received minimally invasive left atrial LV-lead implantation with concomitant LAA closure using the AtriClip. Transesophageal echocardiography (TEE) was performed to intraoperatively guide and control LAA closure. Mean patients age was 64 ± 11.2 years, 67% were male patients. Minimally invasive left-lateral thoracotomy was used in 6 patients while a totally thoracoscopic approach was performed in 2 cases. Epicardial lead implantation was successfully performed in all patients with good pacing threshold (mean 0.8 ± 0.2 V) and sensing values (10.1 ± 2.3 mV). Posterolateral position of the LV lead was achieved in all patients. Furthermore, successful LAA closure was confirmed during TEE in all patients. No procedure-related complications occurred in any of the patients. Two patients additionally received simultaneous laser lead extraction during the same procedure. Complete lead extraction was achieved in both patients. All patients were extubated in the OR and had an uneventful postoperative course. Our study highlights a novel treatment approach for patients with atrial fibrillation and the necessity of epicardial LV leads. Placement of a posterolateral LV lead position with concomitant occlusion of the left atrial appendage via a minimally-invasive left-lateral thoracotomy or even a totally thoracoscopic approach is safe and feasible with superior cosmetic result and complete occlusion of the left atrial appendage.

Repositioning and optimization of left ventricular lead position in nonresponders to cardiac resynchronization therapy is associated with improved ejection fraction, lower NT-proBNP values, and fewer heart failure symptoms.

Observational data suggest that an anterior or apical left ventricular (LV) position in cardiac resynchronization therapy (CRT) is associated with worse outcome and higher likelihood of "nonresponse." It is not known whether the benefits of optimizing LV lead position in a second procedure outweighs the procedural risks. To evaluate the clinical effects of LV lead repositioning. During the period 2015-2020, we identified all patients in whom the indication for the procedure was LV lead repositioning owing to "nonresponse" in combination with suboptimal LV lead position. All patients were followed with a structured visit 6 months post LV lead revision. Heart failure hospitalization and mortality data were gathered from the medical records and cross-checked with the population registry. A total of 25 patients were identified who fulfilled the inclusion criteria. All procedures were successful in establishing LV lead pacing in a lateral mid or basal location. Median follow-up was 2.5 years [1.1-3.7]. There were improvements in NYHA class (mean -0.5 ± 0.5 class, P < .001), LV ejection fraction (+5 [interquartile range 2-11] absolute %, P = .01), QRS duration (-36 [-44 to -8], P < .001) and N-terminal pro-brain natriuretic peptide (NT-proBNP) (-615 [-2837 to +121] ng/L, P = .03). Clinical outcome was similar to a reference population with CRT (P = ns). In nonresponders to CRT with either an anterior or inferior LV lead position, it was feasible to perform LV lead repositioning in all cases, with a low complication rate. Changing the LV lead position was associated with improved LV ejection fraction, larger QRS reduction, and larger NT-proBNP reduction.

Treatment of cardiac resynchronization therapy non-responders: current approaches and new frontiers

ABSTRACT Introduction Cardiac resynchronization therapy (CRT) has developed into a very effective technology for patients with decreased systolic function and has substantially improved patients’ clinical course. However, non-responsiveness to CRT, described as lack of reverse cardiac chamber remodeling, leading to lack to improve symptoms, heart failure hospitalizations or mortality, is common, rather unpredictable, and not fully understood. Areas covered This article aims to discuss key factors that are impacting CRT response, from patient selection to LV lead position, to structured follow-up in CRT clinics. Secondly, common causes and interventions for CRT non-responsiveness are discussed. Next, insight is given into technologies representing new and feasible interventions as well as pacing strategies in this group of patients that remain challenging to treat. Finally, an outlook is given into future scientific development. Expert opinion Despite the progress that has been made, CRT non-response remains a significant and complex problem. Patient management in interdisciplinary teams including heart failure, imaging, and cardiac arrhythmia experts appears critical as complexity is increasing and CRT non-response often is a multifactorial problem. This will allow optimization of medical therapy, and the use of new integrated sensor technologies and telemedicine to ultimately optimize outcomes for all patients in need of CRT.

Status and Update on Cardiac Resynchronization Therapy Trials.

After decades of clinical use, cardiac resynchronization therapy (CRT) can be considered an established therapy. However, there are multiple open questions to be addressed that shall further improve the proportion of patients responding to CRT. Progress in better understanding the relationship between electrical and mechanical disorder in patients with heart failure with ventricular conduction abnormalities is important. This article presents and discusses ongoing studies in different areas of CRT research, including patient selection by novel diagnostic tools, extension of clinical criteria, left ventricular lead positioning and pacing site selection, optimization of CRT delivery and programming, and selection of device type.

Novel active fixation lead guided by electrical delay can improve response to cardiac resynchronization therapy in heart failure.

AimsCardiac resynchronization therapy (CRT) for heart failure (HF) recently has shown optimal results by targeting electrically delayed sites in coronary sinus (CS) branches. However this purpose often cannot be reached because of unstable left ventricular (LV) lead position. In current study were assessed the long‐term effects of the novel active fixation LV lead in CS, guided by electrical delay (QLV), in patients with HF due to coronary artery disease.MethodsOne hundred eighty‐five consecutive patients underwent CRT with intraoperative evaluation of QLV in the target position of the LV lead. When the novel active fixation LV lead was available, 98 consecutive patients received it, composing the Fix group. They were compared with 87 patients with a conventional passive fixation lead (No Fix group). The final LV lead position was assessed by fluoroscopy. Clinical response to CRT was assessed within a period of about 3 years: patients experiencing HF rehospitalization and death due to HF were defined as non‐responders.ResultsThere were no significant differences between groups in the final position of LV lead in left anterior oblique view (Pearson χ 2 = 0.12; P = 0.73). In right anterior oblique view, a basal position was reached more in the Fix group (38%) than in the No Fix group (6.5%) (Pearson χ 2 = 23.095; P < 0.001). QLV was significantly greater in the Fix group (122.6 ± 33.2 ms; SE = 3.6) than in the No Fix group (97.5 ± 37.8 ms; SE = 4.9) (t = 4.17; P < 0.001). Rehospitalizations for HF were 37 in the No Fix group and 14 in the Fix group. Deaths due to HF were 49 in the No Fix group and 18 in the Fix group. Survival analysis, assessed by Cox regression, showed that the Fix group had a better outcome both for HF rehospitalizations [hazard ratio (HR) = 0.48; 95% confidence interval (CI) = 0.25–0.9; P = 0.023] and death due to HF (HR = 0.55; 95% CI = 0.31–0.97; P = 0.04) in comparison with the No Fix group. Adjustment for baseline characteristics by multivariate analysis showed that an active fixation lead in CS, as a covariate, was still significant both for HF rehospitalizations (HR 0.46; 95% CI = 0.24–0.88; P = 0.019) and for death due to HF (HR 0.5; 95% CI = 0.28–0.9; P = 0.021).ConclusionsThe novel active fixation LV lead allowed to target sites with greater QLV. Often maximum QLV was documented in basal segments, were stability of conventional passive fixation leads is not enough. Patients receiving it experienced less HF rehospitalizations and less death due to HF. Active fixation lead in CS guided by QLV can improve long‐term prognosis in patients with HF due to coronary artery disease undergoing to CRT.

Optimal left ventricular lead positioning during cardiac resynchronisation therapy; a comparison of 2 methods

Abstract Background/Introduction Superior response to CRT and improved clinical outcomes can be achieved when placing the left ventricular (LV) lead at the site of latest mechanical activation and avoiding regions of scar during cardiac resynchronisation therapy (CRT). The site of latest mechanical activation can be identified using speckle-tracking echocardiography, whilst the area of latest electrical activation can be assessed by measuring QLV, the time from the initial deflection of the surface QRS complex to sensing at the LV lead electrode. It remains unclear if the two techniques are interchangeable and whether the site of latest mechanical activation is related to the site of latest electrical activation, or sensed electrical signals correspond to sites of scar. Purpose To determine whether electrical targeting of LV lead position corresponds to echo-guided mechanical targeting and whether myocardial electrogram signals can predict areas of myocardial scar Methods This was a pilot study of patients receiving CRT, in sinus rhythm with severe LV impairment (ejection fraction ≤35%) and left bundle branch block (LBBB) with QRS ≥130ms. Ethics approval was obtained, and written consent was sought. Participants underwent echocardiographic speckle-tracking 2-dimensional radial strain imaging to identify amplitude and time to peak contraction of posterior, posterolateral, lateral, anterolateral and anterior segments. During CRT implant, the sensed R wave and QLV were measured at the respective branch of the coronary sinus, where the anatomy permitted. The site of latest mechanical was compared to the site of latest electrical activation and classified as concordant (same site), adjacent (within 1 segment), or remote (2 segments away). The strain amplitude was compared to the sensed R wave and time to mechanical activation with QLV. Results Seventeen patients (13 male) were studied, mean age 74.2 (SD 8.7). Mean QRS was 161 ms (SD 18), mean PR 186 ms (SD 37). A modest and significant positive correlation was found between the site of latest mechanical and latest electrical activation (Pearson r=0.66, p 0.004). The site of latest electrical activation was concordant with latest mechanical activation in 13 patients (76.5%), adjacent in 4 patients (23.5%) and remote in none. There was no apparent association between sensed R wave and strain amplitude (Pearson r=0.2, p=0.12) or between QLV and time to mechanical activation (Pearson r=0.1, p=0.5). Conclusion A significant positive correlation was found between the site of latest mechanical and latest electrical activation in patients undergoing CRT implant. Electrical targeting might be a suitable alternative to mechanical targeting particularly when imaging is not available, however, does not appear to discriminate scar. Future larger studies are needed to confirm our findings and determine whether QLV can be used as an alternative method for targeting LV lead placement. Funding Acknowledgement Type of funding sources: None.

B-PO03-192 REDUCTION IN QRS AREA CORRELATES WITH HEMODYNAMIC RESPONSE DURING CARDIAC RESYNCHRONIZATION THERAPY - DEVICE IMPLANTATION

Previous studies have shown that reduction in QRS area after cardiac resynchronization therapy (CRT) is associated with improved long-term clinical outcome. To investigate whether reduction in QRS area is associated with hemodynamic improvement and whether QRS area reduction could be used for CRT optimization. A total of 78 patients with an indication for CRT were prospectively included in 4 hospitals. QRS area was calculated from vectorcardiograms synthesized from 12-lead ECGs. Hemodynamic response was assessed invasively as the maximum rate of percentual left ventricular pressure (%LVdP/dtmax) rise. QRS area change was studied in relation to LV-lead position (n=26), proximal versus distal LV lead position (n=27), and VV-delay (n=25). Combining all measurements in all patients showed a significant correlation between QRS area reduction and %LVdP/dTmax increase (R=0.49, P<0.0001). Also, when one fixed routine implantation setting was used for each patient (lateral lead position, distal, AV-delay 120-150ms, VV-delay 0ms) this correlation was present (figure, panel A). In 21 patients in which at least 3 lead positions were available, there was also a significant correlation between QRS area reduction and %LVdP/dtmax increase (panel B). For VV-delay, 25 other patients as well showed a significant correlation (average R=0.53, p<0.0001). Within patients, QRS area reduction is associated with %LVdP/dtmax increase with various LV lead positions and VV-intervals. Therefore, QRS area, which is an easily obtainable and objective parameter, might be a promising tool for optimization of LV lead position and device programming in CRT.

Reduction in QRS area correlates with hemodynamic response during CRT-device implantation

Abstract Funding Acknowledgements Type of funding sources: None. Background Previous studies have shown that reduction in QRS area after cardiac resynchronization therapy (CRT) is associated with improved long-term clinical outcome. Purpose To investigate whether reduction in QRS area is associated with hemodynamic improvement and whether QRS area reduction could be used for CRT optimization, with respect to LV lead position and device programming in individual patients. Methods A total of 78 patients with indication for CRT were prospectively included in 4 hospitals. QRS area was calculated from vectorcardiograms that were synthesized from 12-lead ECG’s. Acute hemodynamic response was assessed invasively as the maximum rate of percentual left ventricular (LV) pressure (%LVdP/dtmax) rise. QRS area reduction was studied in relation to LV-lead position (n = 26), proximal versus distal LV lead position (n = 27), and VV-delay (n = 25). Results Combining all measurements in all patients showed a significant correlation between QRS area reduction and %LVdP/dTmax increase (R = 0.49, P &amp;lt; 0.0001). Also, when one fixed routine implantation setting was used for each patient (lateral lead position, distal, AV-delay 120-150ms, VV-delay 0ms) this correlation was present (R = 0.45, p &amp;lt; 0.0001, figure panel A). In 21 patients in which at least 3 lead positions were available there was also a significant correlation between QRS area reduction and %LVdP/dtmax increase (average R = 0.69, p &amp;lt; 0.0001, panel B). For VV-delay, 25 other patients as well showed a significant correlation (average R = 0.53, p &amp;lt; 0.0001). Conclusion Within patients, QRS area reduction is associated with %LVdP/dtmax increase with various LV lead positions and VV-intervals. Therefore, QRS area, which is an easily obtainable and objective parameter, might be a promising tool for optimization of LV lead position and device programming in CRT. Abstract Figure.

Acute response to cardiac re-synchronization therapy: ventricular properties adaptation?

Abstract Background Cardiac re-synchronization therapy (CRT) reduces mortality and hospitalization in patients with heart failure, reduced left ventricular ejection fraction (LVEF) and left bundle branch block (LBBB). However, there is no conclusive evidence on baseline parameters able to discriminate responder vs non-responder patients. Purpose In this study, we tested whether echocardiographic parameters describing LV dyssynchrony and efficiency may predict an acute LV recovery after CRT and whether lead position can modify such relationship. Methods We enrolled 65 consecutive patients (75% males, aged 71.2±10.5 years) referred for CRT according to current guidelines; 45% had an underlying ischaemic cardiopathy and 1/3 of them presented diabetes mellitus. We performed a CRT-off and CRT–on 2D and 3D echocardiography during devices optimization (time between programming change 10/12 min). We evaluated ventricular dyssynchrony by speckle-tracking analysis based on temporary uniformity of strain (TUS) 3D longitudinal and circumferential. We also derived non-invasive myocardial efficiency (Effic) by interaction between pressure work index (PWI), representing an estimation of myocardial oxygen consumption, and mechanical external work. We indicated as concordant those patients presenting a LV lead position (defined from a chest X-ray using 2 orthogonal views) in the same segment as the latest systolic 3D circumferential strain curves. Results In the CRT-on phase, a non-statistically significant raise in LVEF was observed [from 0.37 (0.28–0.46) to 0.41 (0.34–0.47), p=0.27]. No improvement in both longitudinal and circumferential 3D TUS was demonstrated during CRT-on (p=0.44 and 0.47, respectively). Conversely, the gain in Effic from CRT-off to CRT-on phase was overall significant (from 0.43±0.14 to 0.50±0.16; p&amp;lt;0.001). After switching to CRT-on, the increase in longitudinal 3D TUS was higher in concordant compared to discordant patients (from 0.83±0.08 to 0.87±0.07 vs 0.88±0.11 to 0.87±0.12, respectively), but without significant interaction (interaction p 0.24). No interaction was also found between variations of PWI after switching to CRT-on and LV lead position (concordant: from 12.99±4.18 to 12.84±2.99 ml/min/100g; discordant: from 13.58±3.89 to 13.95±3.97 ml/min/100g; interaction p 0.75). Conclusions Effic was overall acutely augmented during CRT-on phase in patients with LV dysfunction undergoing cardiac re-synchronization. In the acute phase, no significant relationship between LV changes in speckle-tracking analyses after CRT and LV lead position was found. 2-way ANOVA for myocardial efficiency Funding Acknowledgement Type of funding source: None

Lateral left ventricular lead position is superior to posterior position in long-term outcome of patients underwent cardiac resynchronization therapy

Abstract Background Preferring side branch of coronary sinus during cardiac resynchronization therapy (CRT) implantation is empirical due to the limited data on the association of left ventricular (LV) lead position and long-term clinical outcome. Purpose We evaluated the long-term all-cause mortality by LV lead non-apical positions and further characterized them by interlead electrical delay (IED). Methods In our retrospective database 2087 patients were registered between 2000 and 2018. Those with non-apical LV lead locations were classified into anterior (n=108), posterior (n=643), and lateral (n=1336) groups. All-cause mortality was assessed by Kaplan-Meier and Cox analyses. Echocardiographic response was measured 6 months after CRT implantation. Results During the median follow-up time of 3.7 years, 1150 (55.1%) patients died, 710 (53.1%) with lateral, 78 (72.2%) with anterior and 362 (56.3%) with posterior positions. Patients with lateral position had significantly better outcome in all-cause mortality compared to others (HR 0.80; 95% CI: 0.71–0.90; p&amp;lt;0.0001), which was also confirmed by multivariate analysis after adjusting for relevant clinical covariates (HR 0.81; 95% CI: 0.72–0.91; p&amp;lt;0.0001). When echocardiographic response was evaluated in the lateral group, patients with an IED longer than 110 ms (ROC AUC 0.63; 95% CI: 0.53–0.73; p=0.012) showed 2.1 times higher odds of improvement in echocardiographic response 6 months after the implantation. Conclusions In this study we proved that after CRT implantation only the lateral LV lead location was associated with long-term mortality benefit. Moreover, patients with this position showed the greatest echocardiographic response over 110 ms IED. Survival of total patient cohort Funding Acknowledgement Type of funding source: None

Lateral left ventricular lead position is superior to posterior position in long-term outcome of patients who underwent cardiac resynchronization therapy.

AimsPreferring side branch of coronary sinus during cardiac resynchronization therapy (CRT) implantation has been empirical due to the limited data on the association of left ventricular (LV) lead position and long‐term clinical outcome. We evaluated the long‐term all‐cause mortality by LV lead non‐apical positions and further characterized them by interlead electrical delay (IED).Methods and resultsIn our retrospective database, 2087 patients who underwent CRT implantation were registered between 2000 and 2018. Those with non‐apical LV lead locations were classified into anterior (n = 108), posterior (n = 643), and lateral (n = 1336) groups. All‐cause mortality was assessed by Kaplan–Meier and Cox analyses. Echocardiographic response was measured 6 months after CRT implantation. During the median follow‐up time of 3.7 years, 1150 (55.1%) patients died—710 (53.1%) with lateral, 78 (72.2%) with anterior, and 362 (56.3%) with posterior positions. When we investigated the risk of all‐cause mortality, there was a significantly lower rate of death in patients with lateral LV lead location when compared with those with an anterior (P < 0.01) or posterior (P < 0.01) position. Multivariate analysis after adjustment for relevant clinical covariates such as age, sex, ischaemic aetiology, left bundle branch block morphology, atrial fibrillation, and device type revealed consistent results that lateral position is associated with a significant risk reduction of all‐cause mortality when compared with anterior [hazard ratio 0.69; 95% confidence interval (CI) 0.55–0.87; P < 0.01] or posterior (hazard ratio 0.84; 95% CI 0.74–0.96; P < 0.01) position. When echocardiographic response was evaluated within the lateral group, patients with an IED longer than 110 ms (area under the receiver operating characteristic curve, 0.63; 95% CI 0.53–0.73; P = 0.012) showed 2.1 times higher odds of improvement in echocardiographic response 6 months after the implantation.ConclusionsIn this study, we proved in a real‐world patient population that after CRT implantation, lateral LV lead location was associated with long‐term mortality benefit and is superior to both anterior and posterior positions. Moreover, patients with this position showed the greatest echocardiographic response over 110 ms IED.

Balloon angioplasty of cardiac vein in a patient treated by cardiac resynchronization therapy

Introduction. Cardiac resynchronization therapy (CRT) reduces mortality and hospitalization in patients with symptomatic heart failure and left bundle branch block (LBBB) on optimal drug therapy. Among all, the reasons for ?non-response? to CRT pacemaker could be the failure to achieve optimal left ventricular (LV) lead position due to severe curve or stenosis/occlusion of the target vein. Case report. We presented a 79-old-male patient, New York Heart Association (NYHA) class III, with atrial fibrillation, chronic coronary syndrome (CCS), and prior myocardial infarction. The patient underwent coronary artery bypass surgery and mechanical prosthetic aortic valve implantation. He was indicated for CRT. The patient?s venogram revealed ostial/proximal severe curve and stenosis of the posterolateral vein, the only vein of coronary sinus that led to anatomically optimal LV segment for stimulation. After the balloon angioplasty of the curved and stenotic portion of the target vein with compliant balloon 4.0 ? 30 mm, a satisfactory and stable position of quadripolar LV lead was achieved. Conclusion. Compliant balloon angioplasty could be a safe and efficient way to override severe coronary vein stenosis in some CRT cases.

P536Reverse remodeling after cardiac resynchronization therapy is associated with improvement of contractile asymmetry in the area of left ventricular lead position

Abstract Background One third of patients receiving cardiac resynchronization therapy (CRT) do not respond to the treatment, possibly due to suboptimal lead position and persistent dyssynchronous left ventricular (LV) contraction. Purpose To assess the influence of LV lead position on improvement of contractile asymmetry and its significance for LV reverse remodeling after CRT. Methods Patients with heart failure and left bundle branch block undergoing CRT implantation were studied retrospectively. Assessment of mechanical delay within the LV was assessed using a recently developed index of contractile asymmetry (ICA). ICA was calculated as standard deviation of differences in systolic strain rate in the opposing LV walls derived from curved anatomical M-mode plots. LV was divided into 12 equally sized 30-degree sectors. Spline interpolation was used to estimate ICA in six opposing sector pairs permitting quantification of regional contractile asymmetry in the entire LV. Position of LV lead tip was assessed by thoracic computed tomography (CT). Response to CRT was defined as a reduction of LV end-systolic volume (ESV) ≥15% after 6 months. Results Study population (n= 26) consisted of 65.4% males, 68 ± 10 years, ischemic etiology in 42.3%, LV ejection fraction 24.1 ± 5.8%, QRS duration 171 ± 22 ms. CRT response was present in 18 (69.2%) patients. Pre-implantation ICA in the LV sector containing LV lead was 0.75 ± 0.24 s-1 in responders vs. 0.46 ± 0.16 s-1 in non-responders (p = 0.003). Reduction of ICA in the LV sector with LV lead was directly correlated with reduction of LV ESV after CRT (r = 0.46, p = 0.02) (Figure 1). ICA reduction in the LV sector with LV lead was -0.24 ± 0.28 s-1 in responders and -0.05 ± 0.16 s-1 in non-responders (p = 0.03). Meanwhile, reduction of ICA in the LV sectors located 60 degrees clockwise and 60 degrees counterclockwise away from the LV sector with LV lead (remote LV sectors) did not differ significantly between responders and non-responders: -0.12 ± 0.15 s-1 vs. -0.06 ± 0.1 s-1 (p = 0.28). Likewise, no significant correlation between reduction of ICA in remote LV sectors and LV ESV reduction was observed (p = 0.11). Conclusion Pre-implantation contractile asymmetry in the LV lead target area is associated with a positive response to CRT. Simultaneously, the degree of LV reverse remodeling after CRT seems to correlate with the magnitude of improvement of contractile asymmetry specifically in the region of LV lead location. Abstract Figure 1