Left Ventricular Lead Research Articles

Effect of QRS area reduction and myocardial scar on the hemodynamic response to cardiac resynchronization therapy

Vectorcardiographic QRS area (QRSarea) predicts clinical outcomes after cardiac resynchronization therapy (CRT). Myocardial scar adversely affects clinical outcomes after CRT. The purpose of this study in patients with an ideally deployed quadripolar left ventricular (LV) lead (QUAD) was to determine whether reducing QRSarea leads to an acute hemodynamic response (AHR) and whether scar affects this interaction. Patients (n = 26; age 69.2 ± 9.12 years [mean ± SD]) underwent assessment of the maximum rate of change of LV pressure (ΔLV dP/dtmax) during CRT using various left ventricular pacing locations (LVPLs). Cardiac magnetic resonance (CMR) scan was used to localize LV myocardial scar. Interindividually, ΔQRSarea (area under the receiver operating characteristic curve [AUC] 0.81; P <.001) and change in QRS duration (ΔQRSd) (AUC 0.76; P <.001) predicted ΔLV dP/dtmax after CRT. Scar burden correlated with ΔQRSarea (r = 0.35; P = .003), ΔQRSarea (r = 0.35; P = .003), and ΔQRSd (r = 0.46; P <.001). A reduction in QRSarea was observed with LVPLs remote from scar (-3.28 ± 38.1 μVs) or in LVPLs in patients with no scar at all (-43.8 ± 36.8 μVs), whereas LVPLs over scar increased QRSarea (22.2 ± 58.4 μVs) (P <.001 for all comparisons). LVPLs within 1 scarred LV segment were associated with lower ΔLV dP/dtmax (-2.21% ± 11.5%) than LVPLs remote from scar (5.23% ±10.3%; P <.001) or LVPLs in patients with no scar at all (10.2% ± 7.75%) (both P <.001). Reducing QRSarea improves the AHR to CRT. Myocardial scar adversely affects ΔQRSarea and the AHR. These findings may support the use of ΔQRSarea and CMR in optimizing CRT using QUAD.

Resynchronization therapy with His bundle pacing in a patient after coronary sinus reducer implantation

Symptomatic heart failure patients with ischemic heart disease may require both coronary sinus reducer (CSR) implantation due to refractory angina pectoris and cardiac resynchronization therapy (CRT). Optimal approach to CRT in these patients is unknown as CSR implantation in the distal coronary sinus could deter left ventricular lead placement and thus preclude conventional CRT with biventricular pacing. We present a 70-year-old patient with ischemic cardiomyopathy and wide QRS complex after CSR implantation in whom we achieved successful cardiac resynchronization with His bundle pacing (HBP). HBP led to acute improvement in hemodynamic parameters and exercise capacity that persisted at follow-up. This case represents the first description of successful CRT with HBP in a patient after CSR implantation. HBP could present a feasible and safe resynchronization approach in these patients.<Learning objective: Optimal approach to cardiac resynchronization therapy in patients after coronary sinus reducer (CSR) implantation remains unknown as CSR implantation in the distal coronary sinus may deter left ventricular lead implantation and thus preclude conventional biventricular pacing. His bundle pacing could present a feasible and safe resynchronization approach in this growing group of patients.>

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.

P1492Comparison of the long-term performance of the quadripolar IS-4 and the bipolar IS-1 left ventricular lead for cardiac resynchronization therapy

Abstract BACKGROUND The implantation of left ventricular (LV) leads for cardiac resynchronization therapy (CRT) and the management of lead-related complications can be challenging. The introduction of the quadripolar IS-4 LV lead may have facilitated the implantation procedure and may have reduced lead-related complications. Data of long-term follow-up (FU) comparing the IS-4 lead with the IS-1 LV lead are rare and conflicting. PURPOSE Comparison of lead-related complications and all-cause mortality between CRT patients who received an IS-4 or an IS-1 LV lead in the long-term FU. METHODS Adults with an indication for a CRT-Defibrillator or CRT-Pacemaker, a successful endovascular IS-4 or IS-1 LV lead implantation, and a minimal FU of three years were included in this retrospective study. The combined primary endpoint was freedom from lead-related complications defined as (i) occurrence of persisting high pacing threshold (&amp;gt;2.75V/0.4ms), (ii) unresolved phrenic nerve stimulation, (iii) LV lead dislodgement/disruption, (iv) the necessity of re-interventions affecting the LV lead, and (v) LV lead deactivation/explantation. Secondary endpoints were all singular complications and all-cause mortality. RESULTS Eligible for the study were 133 patients (IS-4 n = 66; IS-1 n = 67) with a mean FU of 4.03 ± 1.93 years. Baseline characteristics of both patient groups did not differ significantly. Freedom from lead-related complications was higher in patients with an IS-4 lead as compared to an IS-1 lead (Figure 1; 87.9% vs. 65.7%; p = 0.002). The secondary outcomes showed a higher rate of LV lead dislodgement/disruption (4.5% vs. 17.9%; p = 0.015) in the IS-1 patient group and more patients suffered from unresolved phrenic nerve stimulation with an IS-1 lead (3.0% vs. 13.4%; p = 0.029). LV lead deactivation/explantation during FU and LV lead-related re-interventions were fewer in case of an IS-4 lead (4.5% vs 22.4%; p = 0.003; 6.1% vs. 17.9%; p = 0.036, respectively). The rate of persisting high pacing thresholds and all-cause mortality did not differ (4.5% vs. 9.0%; p = 0.492; 22.7% vs 25.4%; p = 0.721, respectively). CONCLUSION The quadripolar IS-4 LV lead showed in this retrospective study a better long-term performance than the bipolar IS-1 lead. Abstract Figure 1

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

864A modified snare technique improves left ventricular lead implant success and response rate to cardiac resynchronization therapy

Abstract Introduction Left ventricular (LV) lead placement is often the most challenging aspect of cardiac resynchronization therapy (CRT) device implantation, with a failure rate up to 10% due to complex coronary anatomies. Purpose To evaluate the efficacy of a modified snare technique in the LV lead implantation in cases of standard technique failure and to evaluate its impact in the response rate to CRT. Methods A prospective study was conducted of patients indicated for a CRT implant. When LV lead delivery to the target vessel failed using standard techniques, a modified snare technique was implemented, using a secondary coronary sinus delivery sheath introduced through the same venous puncture. Patients were evaluated every 6 months. Efficacy was quantified by long-term surgical intervention rates. Patients were evaluated with transthoracic echocardiography before CRT implant and between 6-12 months post-implant. Patients with ejection fraction (EF) elevation ≥ 10% or LV end-systolic volume (ESV) reduction ≥ 15% were classified as responders. Patients with EF elevation ≥ 20% or LV ESV reduction ≥ 30% were classified as super-responders. Time to surgical revision and mortality were evaluated by the Cox regression and Kaplan-Meier methods. Results From 2015-2019, 566 CRTs were implanted (26.1% female, 72 ± 10.2 years old, follow-up duration 18.9 ± 15.8 months). The standard LV implant technique failed in 94 cases (16.6%), of which the modified snare technique was successful in 92 (97.9%) with LV lead implant in a lateral vein in 94.7% of cases. Baseline clinical characteristics were similar between patients who implanted LV lead with snare vs standard technique (p = NS). The 4-year surgical intervention rate was lower with the modified snare implant technique than with the standard technique (3.2% vs. 10.2%, HR 0.26, 95% CI 0.08-0.84, p &amp;lt; 0.05), with a relative risk reduction of 74% and a number needed to treat to prevent one surgical intervention of 14. The intervention rate was also lower regarding LV lead implant failure or dislodgement rates (0% vs. 5.3%, p &amp;lt; 0.05). Major complications were similar between groups. In addition, the response rate to CRT was higher in the modified snare technique than in the standard approach (71.1% vs 55.0%, p &amp;lt; 0.05). In patients who implanted the LV lead with the snare technique, EF increased from 28.1 ± 8.2% to 36.1 ± 11.1% (p &amp;lt; 0.05) and LV ESV decreased from 127.8 ± 64.0mL to 99.8 ± 61.1mL (p = 0.01). The super-response rate was similar between groups (33.3% vs 27.8%, p = NS). Conclusion For challenging coronary sinus anatomies that preclude LV lead placement by standard methods, this modified snare alternative was effective, with significantly lower surgical intervention rates and a higher response rate to resynchronization therapy. This higher than expected response rate with the snare technique, evaluated by remodeling criteria, may be explained by the implant of LV lead in the desired target lateral vein. Abstract Figure.

Evaluating multisite pacing strategies in cardiac resynchronization therapy in the preclinical setting.

BackgroundMultisite pacing strategies that improve response to cardiac resynchronization therapy (CRT) have been proposed. Current available options are pacing 2 electrodes in a multipolar lead in a single vein (multipoint pacing [MPP]) and pacing using 2 leads in separate veins (multizone pacing [MZP]).ObjectiveThe purpose of this study was to compare in a systematic manner the acute hemodynamic response (AHR) and electrophysiological effects of MPP and MZP and compare them with conventional biventricular pacing (BiVP).MethodsHemodynamic and electrophysiological effects were evaluated in a porcine model of acute left bundle branch block (LBBB) (n = 8). AHR was assessed as LVdP/dtmax. Activation times were measured using >100 electrodes around the epicardium, measuring total activation time (TAT) and left ventricular activation time (LVAT).ResultsCompared to LBBB, BiVP, MZP, and MPP reduced TAT by 26% ± 10%, 32% ± 13%, and 32% ± 14%, respectively (P = NS between modes) and LVAT by 4% ± 5%, 11% ± 5%, and 12% ± 5%, respectively (P <.05 BiVP vs MPP and MZP). On average, BiVP increased LVdP/dtmax by 8% ± 4%, and optimal BiVP increased LVdP/dtmax by 13% ± 4%. The additional improvement in LVdP/dtmax by MZP and MPP was significant only when its increase during BiVP and decrease in TAT were poor (lower 25% of all sites in 1 subject). The increase in LVdP/dtmax was larger when large interelectrode distances (>5 cm vs <2.2 cm) were used.ConclusionIn this animal model of acute LBBB, MPP and MZP create similar degrees of electrical resynchronization and hemodynamic effect, which are larger if interelectrode distance is large. MPP and MZP increase the benefit of CRT only if the left ventricular lead used for BiVP provides poor response.

Novel two-lead cardiac resynchronization therapy system provides equivalent CRT responses with less complications than a conventional three-lead system: Results from the QP ExCELs lead registry.

IntroductionThe novel two‐lead cardiac resynchronization therapy (CRT)‐DX system utilizes a floating atrial dipole on the implantable cardioverter‐defibrillator lead, and when implanted with a left ventricular (LV) lead, offers a two‐lead CRT system with AV synchrony. This study compared complication rates and CRT response among subjects implanted with a two‐lead CRT‐DX system to those subjects implanted with a standard three‐lead CRT‐D system.Methods and ResultsA total of 240 subjects from the Sentus QP—Extended CRT Evaluation with Quadripolar Left Ventricular Leads postapproval study were selected to identify 120 matched pairs based on similar demographic characteristics using a Greedy algorithm. The complication‐free rate was evaluated as the primary endpoint. All‐cause mortality, heart failure hospitalizations, device diagnostic data, New York Heart Association (NYHA) class improvement, and defibrillator therapy were evaluated from clinical data, in‐office interrogations, and remote monitoring throughout the follow‐up period. Complication‐free survival favored the CRT‐DX group with 92.5% without a major complication compared to 85.0% in the CRT‐D cohort (P = .0495; 95% confidence interval: 0.1%‐14.9%) over a mean follow‐up of 1.3 and 1.4 years, respectively. Incidence of all‐cause mortality, heart failure hospitalizations, NYHA changes at 6 months postimplant, and percent of LV pacing during CRT therapy were similar in both device cohorts. Inappropriate shocks were more frequent in the CRT‐D cohort with 5.8% of subjects receiving an inappropriate shock vs 0.8% in the CRT‐DX cohort.ConclusionThe results of this subanalysis demonstrate that the CRT‐DX system can provide similar CRT responses and significantly fewer complications when compared to a similar cohort with a conventional three‐lead CRT‐D system.

40Lateral left ventricular lead position and long interlead electrical delay predict long-term all-cause mortality in cardiac resynchronization therapy patients

Abstract Background There is limited data on the association of left ventricular (LV) lead position and long-term clinical outcome in patients after cardiac resynchronization therapy (CRT). Purpose We evaluated the mid-term echocardiographic response and long-term all-cause mortality of patients who underwent CRT implantation by LV lead non-apical positions and further characterized them by right to left ventricular, interlead electrical delay (IED). Methods In our retrospective registry patients after CRT implantation between 2000 and 2018 were registered. Those with non-apical LV lead location were classified into anterior (n = 111), posterior (n = 652), and lateral (n = 1373) positions. Primary endpoint was all-cause mortality assessed by univariate- and Cox multivariate analyses. Secondary endpoint was echocardiographic response within 6 months after CRT implantation. Results From 2136 patients 1180 (55.2%) reached the primary endpoint during the mean follow up time of 4.5 years. Univariate analysis showed patients with lateral position had significantly better outcome compared to others (HR 0.80; 95% CI: 0.71-0.90; p &amp;lt; 0.01), which was also confirmed by Cox multivariate analysis (HR 0.69; 95% CI: 0.50-0.93; p = 0.02) after adjusting for relevant clinical covariates such as IED and LBBB. The median value of IED was 106 (89/124) ms in the total patient cohort, which was significantly longer in the lateral group [anterior 80 (60/100) ms vs. lateral 110 (91/128) ms vs. posterior 100 (85/120) ms; p&amp;lt; 0.01]. When echocardiographic response was further evaluated in patients with lateral position, those with an IED longer than 110 ms (ROC AUC 0.64, 95% CI: 0.54-0.74; p = 0.01) showed the greatest benefit within 6 months. Conclusions After CRT implantation the most beneficial outcome was associated with lateral left ventricular lead location, moreover the greatest echocardiographic response was found when interlead electrical delay was longer than 110 ms in this group. Abstract Figure. All-cause mortality of total cohort

P534Central sleep apnea in pacing-induced cardiomyopathy: prevalence, improvement by upgrading to cardiac resynchronisation therapy and impact on structural responder rates and long-term outcome

Abstract Funding Acknowledgements ÖNB Jubiläumsfondsprojekt Nr. 15974, ISR grant by Boston Scientific, St. Paul, MN, USA Background Central sleep apnea (CSA) in pacing induced cardiomyopathy (PICM) is poorly studied. Specifically, it is unknown whether upgrading from right ventricular pacing (RVP) to cardiac resynchronisation therapy (CRT) improves CSA. Methods Fifty-three patients with impaired left ventricular ejection fraction, frequent right ventricular pacing due to high-grade atrioventricular block and heart failure symptoms despite optimal medical therapy underwent upgrading to CRT. Within one month after left ventricular lead implantation (but still not activated), sleep apnea was assessed in all participants by single-night polysomnography (PSG). Nineteen patients with moderate or severe CSA defined by an apnea hypopnea index (AHI) &amp;gt; 15 events per hour were re-scheduled for a follow up PSG 3-5 months after initiation of cardiac resynchronization therapy. Of this cohort, thirteen patients with stable mild heart failure agreed to be randomized to CRT versus RVP in a cross-over design. Results CSA (AHI &amp;gt; 5 events per hour) was diagnosed in 26 (49.1%), OSA in 16 (30.2%) patients suffering from PICM . Eleven (20.8%) patients did not have any form of sleep apnea. Moderate to severe CSA (AHI &amp;gt; 15 events per hour) was significantly improved (without specific CPAP therapy) by 102 (96-172) days of CRT: AHI decreased from 39.4 events per hour at baseline to 21.6 by CRT (p &amp;lt; 0.001). Furthermore, CRT led to a substantial decrease in left ventricular endsystolic volumes: baseline 141 ml (103-155), significant improvement under CRT (102 ml, 65-138; p &amp;lt; 0.001), whereas no effect with ongoing RV-pacing (147 ml, 130-161; p = 0.865). Preexistent CSA did not affect the structural response of CRT (56.5% in patients with CSA, 62.5% of patients with obstructive sleep apnea and 54.5% in patients without sleep apnea; p = 0.901) and had no impact on major adverse cardiac events (p = 0.412) and/or survival (p = 0.623) during long-term follow-up. Conclusions CSA is highly prevalent in patients with PICM and is significantly improved by upgrading to CRT. Preexistent CSA does not hamper structural improvement and long-term outcome after upgrading to CRT. Thus, CSA seems to occur as a consequence of PICM, rather than as a pathophysiological mediator. Abstract Figure.

P512New approaches to pacing in children with atrioventricular block

Abstract Introduction The placement of permanent pacemaker is presented as one of the most appropriate procedures in patients with congenital complete atrioventricular block (AVB). Despite video-assisted thoracic surgery (VATS) for epicardial lead placement has demonstrated positive results concerning the feasibility and freedom of complications in adults, its role in pacemaker implantation in children remains unclear. The study aimed to assess the intermediate-term outcomes of video-assisted thoracic pacing in children with congenital complete AVB. Methods From May 2017 to November 2018, six children with complete idiopathic AVB underwent minimally invasive left ventricular lead placements via thoracoscopic video assistance. The procedure was performed under complex intratracheal anesthesia with single-lung ventilation, median operation time was 180 minutes (120–240). Four incisions were made, three of them were used to place the lead on the left ventricular, and one was needed to place the device. All pacing parameters were evaluated in perioperative and follow-up periods. Results Median age at implantation was 3 years (2 to 15 years), median weight 13 kg (12–46 kg). All procedures were completed successfully, pacing thresholds for the active lead measured 0.5-1.1V, with R-wave amplitude of 8-18 mV and impedance of 404-1478 Ohm. Increasing pacing thresholds in the third month after pacemaker implantation occurred in one patient, so anti-inflammatory therapy was assigned. Satisfactory thresholds and impedances with no significant difference with initial values were obtained at the median follow-up of 21 months (range: 10–28 months). Conclusion Video-assisted thoracic pacing may provide a potential alternative to the transthoracic approach of epicardial lead placement in children with congenital AVB.

Comparison of left ventricular lead upgrade vs continued medical care among patients eligible for cardiac resynchronization therapy at the time of defibrillator generator replacement: Predictors of left ventricular lead upgrade and associations with long-term outcomes

Randomized trials evaluating cardiac resynchronization therapy (CRT) have excluded patients with a pre-existing implantable cardioverter-defibrillator (ICD). The association of CRT upgrade with clinical outcomes in patients with a pre-existing ICD is unclear. The purpose of this study was to examine a CRT-eligible population to evaluate clinical outcomes associated with CRT upgrade compared to patients who did not undergo CRT. Using the National Cardiovascular Data Registry (NCDR) ICD Registry between April 2010 and December 2014, we created a hierarchical logistic regression model to identify predictors of CRT upgrade in a CRT-eligible ICD population. In the subpopulation of patients with Medicare-linked claims data, differential outcomes were determined with censoring at 3 years. The primary endpoint of this study was all-cause mortality, with secondary endpoints of rates of hospitalization and procedural complications. CRT upgrade was performed in 75.5% of CRT-eligible patients with pre-existing ICD (n = 15,803). Presence of left bundle branch block conduction was the strongest predictor of CRT upgrade (odds ratio [OR] 4.56; 95% confidence interval [CI] 4.08-5.11; P<.0001). In both unadjusted and adjusted analyses, CRT upgrade was associated with a reduction in mortality at 3 years (unadjusted hazard ratio [HR] 0.80; 95% CI 0.70-0.92; P = .001; adjusted HR 0.84; 95% CI 0.72-0.98; P = .02, respectively). Compared to patients with ICD generator replacement only, patients who underwent CRT upgrade experienced no different 3-year rates of hospitalization (adjusted HR 1.01; 95% CI 0.91-1.12; P = .81) or 1-year periprocedural complication rates (adjusted HR 1.07; 95% CI 0.79-1.45; P = .66). In a national registry of CRT-eligible patients with pre-existing ICD, upgrade to CRT was associated with lower rates of mortality than continued medical management.

862Syncav with multipoint pacing improves acute left ventricular hemodynamics

Abstract Funding Acknowledgements Abbott Introduction SyncAV has been shown to improve electrical synchronization by automatically adjusting atrioventricular delay (AVD) according to the intrinsic atrioventricular conduction time. Additional incremental electrical synchronization may be gained by the addition of second left ventricular (LV) pulse with MultiPoint Pacing (MPP). While the electrical synchronization benefits of SyncAV have been previously explored, there has been no assessment of the acute hemodynamic impact of SyncAV with or without MPP. Objective Evaluate the acute LV hemodynamic impact of SyncAV with and without MPP. Methods Heart failure patients with LBBB and QRS duration (QRSd) &amp;gt; 140 ms undergoing CRT-P/D implant with a quadripolar LV lead were enrolled in this prospective study. A guidewire or catheter with pressure transducer was placed in the LV chamber and the maximum pressure change (dP/dtmax) was recorded during the following pacing modes: intrinsic conduction, conventional biventricular pacing with SyncAV (BiV + SyncAV), and MPP with SyncAV (MPP + SyncAV). Twelve-lead surface ECG was used to determine the patient-tailored SyncAV offset that minimized QRSd. Results Twenty-seven patients (67% male, 44% ischemic, 30 ± 7% ejection fraction) completed the acute recordings. Relative to the intrinsic QRSd of 163 ms, BiV + SyncAV reduced QRSd by 21.5% to 124 ms (p &amp;lt; 0.001 vs. intrinsic) and MPP + SyncAV reduced QRSd by 26.6% to 120 ms (p &amp;lt; 0.05 vs. BiV + SyncAV). Beyond electrical synchronization, SyncAV significantly improved acute hemodynamics. Relative to the intrinsic dP/dtmax of 842 mmHg/s, BiV + SyncAV elevated dP/dtmax by 6.3% to 900 mmHg/s (p &amp;lt; 0.001 vs. intrinsic) and MPP + SyncAV elevated dP/dtmax by 8.8% to 926 mmHg/s (p &amp;lt; 0.005 vs. BiV + SyncAV). Despite both QRSd and dP/dtmax improvement with SyncAV and MPP, correlation between electrical and hemodynamic measurements was poor (R2 = 0.0 for BiV + SyncAV, R2 = 0.1 for MPP + SyncAV). Conclusion SyncAV may significantly improve acute LV hemodynamics in addition to electrical synchrony in LBBB patients. Further incremental improvement was achieved by combining SyncAV with MPP. Abstract Figure.

43Dynamic atrioventricular delay achieves superior electrical synchrony when pacing both ventricles rather than left ventricle alone

Abstract Funding Acknowledgements Abbott Introduction Automatic adjustment of atrioventricular delay (AVD) with SyncAV has been shown to improve electrical synchronization when pacing one or two sites in the left ventricle together with the right ventricle. However, it is unknown if the same benefit can be gained by using SyncAV while pacing only the left ventricle without right ventricular pacing. Purpose Evaluate the acute improvement in electrical synchrony provided by SyncAV with and without MultiPoint Pacing (MPP) during biventricular (BiV) and LV only pacing. Methods Patients with LBBB and QRS duration (QRSd) ≥ 150 ms scheduled for CRT-P/D device implantation with quadripolar LV lead were enrolled in this prospective study. QRSd was measured post-implant from 12-lead surface electrograms by blinded experts during the following pacing configurations: intrinsic conduction, conventional BiV (BiV = RV + LV1), MPP (MPP = RV + LV1 + LV2), LV-only single-site (LVSS = LV1 only), and LV-only MPP (LVMPP = LV1 + LV2). For each pacing mode, SyncAV was enabled (e.g. BiV + SyncAV) with the patient-tailored SyncAV offset that minimized QRSd. As an additional reference, QRSd during BiV was also measured using the nominal static AVD (paced/sensed AVD = 140/110 ms). BiV and LVSS pacing used the latest activating LV cathode, whereas MPP and LVMPP used the two LV cathodes with the widest possible separation (&amp;gt;30mm). All configurations used the minimum programmable RV-LV and LV1-LV2 delays. Results Thirty-five patients (78% male, 33% ischemic, 26% ejection fraction, 165 ms intrinsic QRSd) completed device implant and QRSd assessment. Relative to intrinsic conduction, BiV with nominal AVD reduced the QRSd by 17.5% (p &amp;lt; 0.001 vs intrinsic). Enabling SyncAV with a patient-optimized offset significantly improved QRSd reduction. BiV + SyncAV reduced QRSd by 25.2% (p &amp;lt; 0.001 vs. BiV). The greatest QRSd reduction of 28.9% was achieved by MPP + SyncAV (p &amp;lt; 0.01 vs. BiV + SyncAV). Single- and multi-site LV-only pacing reduced QRSd significantly less than corresponding biventricular modes. LVSS + SyncAV reduced QRSd by 22.5% (p &amp;lt; 0.05 vs. BiV + SyncAV), and LVMPP + SyncAV reduced QRSd by 24.3% (p &amp;lt; 0.05 vs. MPP + SyncAV). As a percent of PR interval, optimal SyncAV offsets were similar for BiV + SyncAV (median: 13%, mean: 17%) vs. MPP + SyncAV (median: 13%, mean 16%, p = 0.35 vs. BiV + SyncAV), and similar for LVSS + SyncAV (median: 20%, mean: 28%) and LVMPP + SyncAV (median: 23%, mean: 26%, p = 0.35 vs. LVSS + SyncAV), but were significantly higher for LV-only settings vs. corresponding BiV/MPP settings (p &amp;lt; 0.01 for both pairs). Conclusion: Greater improvement in electrical synchrony using SyncAV was observed when right ventricular pacing was included with left ventricular pacing. Additional benefit was gained by the addition of a second left ventricular pacing site with MPP in combination with SyncAV in both biventricular and LV only pacing modes. Abstract Figure.

Anterior wall ST-elevation myocardial infarction in biventricular paced rhythm

There is alack of evidence on electrocardiographic criteria for ST-elevation myocardial infarction (STEMI) in patients with biventricular paced rhythm. In all previous case reports of STEMI in biventricular paced rhythm, concordant ST-elevations and/or discordant ST-elevations >5 mm were present. This report describes the case of apatient with anterior STEMI and discordant ST-elevations of less than 5 mm during biventricular stimulation with epicardial left ventricular lead and highlights the importance of comparing the electrocardiogram to previous recordings when STEMI is suspected.

Navigating Challenging Left Ventricular Lead Placements for Cardiac Resynchronization Therapy.

Cardiac resynchronization therapy (CRT) is a mainstay in the management of heart failure patients with electrical dyssynchrony. Left ventricular (LV) lead positioning remains an important variable that predicts the response to CRT. Anatomical and technical challenges can hinder optimal LV lead placement using traditional lead implantation approaches. Knowledge of normal anatomical variants and common anomalies is essential for successful LV lead implants. With advancements in tools and techniques for LV lead delivery, the implanting electrophysiologist can target the optimal LV pacing site, rather than accepting a suboptimal location that is less likely to provide clinical benefit. In this review, we discuss various challenges to achieving optimal LV lead implantation and present strategies to overcome them.

Novel Doppler-guided subxyphoid approach to avoid coronary artery damage during left ventricular epicardial lead placement or ablation.

Subxyphoid active left ventricular epicardial (LVE) lead implants or VT ablation are attractive but remain a challenge due to concerns of coronary artery damage. We aimed to see if Doppler-guided positioning could permit safe LVE lead placement without coronary angiography. We evaluated the feasibility of a Doppler flow-guided subxyphoid epicardial screw-in lead fixation in a swine model. Acute subxyphoid access to the pericardial space was performed in an anesthetized swine model using a deflectable sheath and a modified needle-derived Doppler flow meter. The audio signal and visual display from the Doppler flow meter were recorded. Coronary angiography was performed to verify the catheter location. A SelectSecure Model 3830 lead (Medtronic) was used to assess pacing in the procedure. In both of two swine, the deflectable catheter was inserted into pericardial space via subxyphoid access. The tip of the deflectable catheter with the Doppler was directed to several locations, from quiet (no nearby coronary artery expected) to typical rhythmic pulsatile sound locations which were maximal when superimposed on a coronary artery. Repeated coronary angiograms confirmed the expected findings. A 3830 active lead was fixed into a quiet location for LVE pacing, and confirmed by angiography as distant from a coronary artery. Doppler-guided subxyphoid epicardial screw-in lead placement is feasible once the catheter tip is directed and stabilized in a desired LVE location. This obviates the need for repeated (or any) coronary angiography. The Doppler-guided subxyphoid epicardial procedure may also be applicable for epicardial ventricular arrhythmia ablation procedures.

Cardiac venous injuries: Procedural profiles and outcomes during left ventricular lead placement for cardiac resynchronization therapy

Injury to the cardiac venous structures can complicate left ventricular lead placement for cardiac resynchronization therapy (CRT). Little is known about the outcomes of coronary sinus (CS) dissection with or without perforation. The purpose of this study was to determine the outcomes in patients who had a CS injury during CRT implantation. All patients undergoing procedures for CRT implantation at the Cleveland Clinic (2001-2018) were enrolled in a prospectively maintained registry for procedural profiles and complications. All patients with cardiac venous injuries during the procedures were included. CS injury occurred in 35 of 5011 patients (0.7%; 6 perforations (17.1%), 29 dissections without perforation (82.9%)). In patients with dissection in the absence of perforation, attempts at CS lead placement after dissection were successful in 21 of 29 patients (72.4%). In those with perforation (n=6, 17.1%), CS lead placement was successful in one of them (16.7%). Cardiac tamponade occurred in 2 patients (5.7%), and the procedure was aborted in both of them. Overall, CS lead placement failed in 13 patients (37%) but 9 (25.7%) underwent subsequent CRT with CS lead placement (n=6, 17.1%; median 58 days later) or epicardial leads (n=3, 8.6%). Three of the remaining 4 patients (8.6%) refused to undergo further procedures, and the fourth (2.9%) died of a complicated course. CS injury is not common during CRT implantation procedures and did not preclude successful lead placement in 23 of 35 patients (65.7%) during the index procedure and 6 of 6 (100%) during the subsequent attempted procedures. A low rate of mortality was observed in such patients, but CS injury was associated with increased morbidity.

Performance of a novel active fixation quadripolar left ventricular lead for cardiac resynchronization therapy: Attain Stability Quad Clinical Study results.

The Medtronic Attain Stability Quad lead is a quadripolar left ventricular (LV) lead with an active fixation helix assembly designed to fixate the lead within the coronary sinus and pace nonapical regions of the LV. The primary objective of this study was to determine the safety and effectiveness of this novel active fixation quadripolar LV lead. Patients with standard indications for cardiac resynchronization therapy (CRT) were enrolled. All patients were followed at 3 and 6 months post-implant and every 6 months thereafter until study closure. Pacing capture thresholds (PCTs) were measured at implant and each follow-up and adverse events (AEs) were recorded upon occurrence. Of the 440 patients who underwent implant procedures, placement of the Attain Stability Quad lead was successful in 426 (96.8%). LV lead-related complications occurred in 10 patients (2.3%), including LV lead dislodgement in three patients (0.7%). The percentage of patients with at least one LV pacing vector with a PCT ≤2.5 V at a 6-month follow-up was 96.3%. The LV lead was successfully fixated to the prespecified pacing location in 97.4% of cases. This large, multinational study of the Attain Stability Quad lead demonstrated a high rate of implant success with a low complication rate. The active fixation mechanism allowed precise placement of the pacing electrodes at the desired target region with good PCTs and a very low dislodgement rate.

Extending multipoint pacing CRT battery longevity by swapping left ventricular pulse configurations

Cardiac resynchronization therapy (CRT) with left ventricular (LV) MultiPoint™ pacing (MPP) has been shown to improve CRT response by pacing two LV sites (LV1, LV2). While an additional LV pacing site reduces battery longevity, this cost can be minimized by leveraging an existing device-based capture management algorithm (LVCap™ Confirm). The purpose of this study was to evaluate the MPP battery longevity improvement achieved by configuring LV pacing sites to properly leverage LVCap Confirm. Patients previously enrolled in the MORE-CRT MPP trial with existing MPP-enabled CRT-D devices (Abbott Quadra Assura MP™ CD3371-40QC, Quartet™ LV lead) underwent device interrogation. Device electrical characteristics and estimated battery longevities were compared for various MPP settings. At 2.1 ± 1.1years post-implant, the estimated remaining battery longevity in 65 patients was 70 ± 14months with MPP Off (LV pacing from minimum capture threshold). Enabling MPP with maximal anatomical separation between LV1 and LV2 cathodes reduced longevity by 15 ± 14%. However, swapping the LV1 and LV2 cathodes, such that the LV1 threshold was the higher of the two, allowed the device to take full advantage of the LVCap™ Confirm capture management algorithm, resulting in significantly lower longevity reduction of 9 ± 11% (p < 0.001). Ultimately, a mean MPP battery longevity improvement of 7.7 ± 10.3% (p < 0.001) was achieved by simply swapping LV1/LV2 configurations. By properly leveraging device-based capture management features, the impact of MPP on battery longevity can be significantly reduced.