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Background: Left ventricular (LV) lead implantation for cardiac resynchronization therapy (CRT) may be confounded by contrast load during attempted cannulation and lead dislodgement during guiding catheter splitting. An LV lead implant system with a steerable single catheter that completely avoids the use of guiding catheters when needed, acquires atrioventricular electrograms, measures intracardiac pressures, permits CS angiography, and has the ability to direct a coronary angioplasty wire that will lead the final delivery of LV lead into a CS tributary, may help limit contrast use and avoid lead dislodgement at CS guide sheath removal. Methods and Results: In this article as a proof of concept, we describe the use of this minimalist technique as a first line approach in six patients who had standard indications for CRT. The LV lead was successfully implanted in a target vein in all patients without acute complications. Contrast was not used in half the group and the LV lead was successfully implanted without guiding catheter in four patients. The implantation technique evolved through the series and in the final patient, no guiding sheath or contrast was used. Postimplant lead positions on chest X‐ray and lead parameters were stable in all patients at follow‐up. Conclusion: In proof of concept paper, we describe a technique of LV lead implantation potentially without the use of contrast and standard CS guiding catheters. Once familiar, this approach may provide a less complicated strategy. [ABSTRACT FROM AUTHOR]

Introduction: 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. Methods: 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. Results: 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. Conclusions: 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. [ABSTRACT FROM AUTHOR]

Objectives: Assess safety and performance of novel quadripolar preshaped left ventricular (LV) leads: NAVIGO 4LV 2D ('S shaped') and NAVIGO 4LV ARC ('U shaped')., Methods: Patients indicated for cardiac resynchronisation therapy were enrolled in a multicentre, prospective, controlled study (NAVIGATOR, NCT03279484). Patients were implanted with either a NAVIGO 4LV 2D or ARC lead, and assessed at 10 weeks, 6, 12 and 24 months post-implant. Co-primary safety and performance endpoints were assessed at 10 weeks. Safety endpoint was the patients' rate free from lead-related complications. Performance endpoint was the rate of patients with successful lead performance, defined as LV pacing threshold ≤2.5 V at 0.5 ms on at least one pacing vector, and the absence of phrenic nerve stimulation at the final programmed configuration. Lead-related complications and electrical parameters were monitored throughout study., Results: A NAVIGO 4LV lead was successfully implanted in 211 out of 217 patients (97.2%). The safety endpoint was met, with 100% and 96.1% of patients free from complications for NAVIGO 4LV 2D and ARC, respectively. The performance endpoint was met with 98.1% and 98.9% of patients with a successful lead performance for NAVIGO 4LV 2D and ARC, respectively. Over 12 months, the global complication-free rate for both leads was 97.1% (95% CI: 93.71% to 98.70%), with a mean pacing capture threshold of 1.23 V±0.73 V and a mean impedance of 951 Ω±300.1 Ω., Conclusion: A high implantation success rate and low complication rate was reported for the novel NAVIGO 4LV 2D and ARC leads, along with successful performance up to 12 months., Competing Interests: Competing interests: ET: Honoraria from MicroPort CRM. CI: MicroPort CRM Honoraria for presentations, reimbursement for travel/congress costs, participation in this sponsored research activity. MO: MicroPort CRM Honoraria for presentations., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Steroid-eluting (SE) electrodes suppress local inflammation and lower pacing capture thresholds (PCT); however, their effectiveness on quadripolar left ventricular (LV) leads in the cardiac vein is not fully studied. We evaluated the effectiveness of SE on all four LV pacing electrodes in human subjects enrolled in the Medtronic AttainR © Performa TM quadripolar LV lead study.Methods: A total of 1,097 subjects were included in this evaluation. At each follow-up visit (1,3,6, and 12 months), LV PCT and pacing impedance were measured using either manual or automatedtesting methods. Summary statistics for PCT and impedance values were obtained for implant and each scheduled follow-up visit for all lead models.Results: Average extended bipolar (LV electrode to right ventricular Coil) PCTs for the four LV SE pacing electrodes (LV1, LV2, LV3, and LV4) on the three shapes of the quadripolar LV leads were 1.06±0.97 V, 1.38±1.26 V, 1.51±1.33 V, and 2.25±1.63 V, respectively, at 0.5-ms pulse width. PCTs remained low and stable through out the 12-month follow-up period.Conclusion: This clinical trial demonstrated that SE on all LV pacing electrodes is associated with low and stable PCTs for all quadripolar LV lead electrodes, resulting in multiple viable vectors for LV pacing. The large number of available vectors facilitates basal pacing, avoidance of PNS, and potentially prolongs generator longevity due to lower PCTs. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Cardiac resynchronization using a left ventricular (LV) epicardial lead placed in the coronary sinus is now routinely used in the management of heart failure patients. LV endocardial pacing is an alternative when this is not feasible, with outcomes data sparse. Objective: To review the available evidence on the efficacy and safety of endocardial LV pacing via meta‐analysis. Methods: EMBASE, MEDLINE, and COCHRANE databases with the search term “endocardial biventricular pacing” or “endocardial cardiac resynchronization” or “left ventricular endocardial” or “endocardial left ventricular.” Comparisons of pre‐and post‐QRS width, LV ejection fraction (LVEF), and New York Heart Association (NYHA) functional classification was performed, and mean differences (and respective 95% confidence interval [CI]) applied as a measurement of treatment effect. Results: Fifteen studies, including 362 patients, were selected. During a mean follow‐up of 40 ± 24.5 months, death occurred in 72 patients (11 per 100 patient‐years). Significant improvements in LVEF (mean difference 7.9%, 95% CI 5–10%, P < 0.0001; I2 = 73%), QRS width (mean difference: –41% 95% –75 to –7%; P < 0.0001; I2 = 94%), and NYHA class (mean difference: –1.06, 95% CI –1.2 to –0.9, P < 0.0001; I2 = 60%), (all P < 0.0001) occurred. Stroke rate was 3.3–4.2 per 100 patient‐years, which is higher than equivalent heart failure trial populations and recent meta‐analysis that included small case series. Conclusion: LV endocardial lead implantation is a potentially efficacious alternative to CS lead placement, but preliminary data suggest a potentially higher risk of stroke during follow‐up when compared to the expected incidence of stroke in similar cohorts of patients. [ABSTRACT FROM AUTHOR]

Background A cardiac lead with a side helix for active fixation to the coronary vein wall (Attain Stability®, Model 20066, Medtronic, Minneapolis, MN, USA) recently received CE Mark. The lead is designed to improve left ventricular (LV) placement and reduce dislodgement rates. The extractability of this active fixation LV lead has not been studied extensively. Methods Seventeen sheep were implanted with either an LV lead with a side helix (Model 20066, Model 20096, Medtronic) or a unipolar LV lead (Model 4193, Medtronic) as a control. Leads were extracted at approximately 26, 52, or 118 weeks. Standard extraction methodology was employed with quantitative traction up to 907 g (2 lbs.) using a locking stylet. Gross pathology and histology of the heart with particular attention to the lead tracts were performed. Results All leads were successfully removed in their entirety and required significantly less than 1 kg of traction force. The side helix disengaged from the vein as designed and resulted in no complications. No cardiac tissue was observed on any extracted lead. Gross pathology and histology were devoid of any helix-induced lesions in the vascular structures. The epicardium over the side helix was normal and the fibrotic reaction around the helix was not significantly different from that around the nonhelix portions of the study leads or the control lead. Conclusion Extraction of the side helix, active fixation LV lead from the coronary veins in the sheep model is safe, without procedural complexity, and free of complications after long-term LV lead implant duration. [ABSTRACT FROM AUTHOR]

Introduction Optimal left ventricular (LV) lead position in patients undergoing cardiac resynchronization therapy (CRT) is crucial to achieve an optimal effect on hemodynamics. Due to various difficulties, up to 30% of transvenous LV lead placements fail, or a suboptimal position is achieved. Surgical epicardial LV lead placement could be performed at a position anticipated to be the optimal site. This could have a more favorable effect, which may be expressed by increased improvement in left ventricular ejection fraction (LVEF) and cardiac perfusion. The objective of this trial is to compare transvenous versus epicardial LV lead placement in CRT in a randomized fashion Methods and results Fifty-two patients were randomized to either epicardial or transvenous approach. All patients received an ICD with CRT. Patients were followed for 6 months after device implant. Primary endpoint was the degree of change in cardiac perfusion measured by myocardial perfusion scintigraphy. LVEF equally improved in both groups, from 24% to 36% in the transvenous group versus 25% to 35% in the epicardial group (P = 0.797). Cardiac perfusion, expressed as summed stress score, improved in both groups without a significant difference as well (P = 0.727). Complication rate was similar, respectively 6 and 7 patients had any complication. Admission time was significantly longer in the epicardial group with 2 (2-7) versus 3 (2-32) days (P <0.001). Conclusion Epicardial LV lead placement does not result in additional improvement of LVF or myocardial perfusion compared to the conventional transvenous in CRT. [ABSTRACT FROM AUTHOR]

Left ventricular lead placement in the appropriate branch of coronary sinus is the key to successful cardiac resynchronization therapy (CRT) and this step is technically challenging. We describe a case of non-ischemic cardiomyopathy with heart failure, taken up for cardiac resynchronization therapy with defibrillator (CRT-D) implantation. The quadripolar left ventricular lead was impossible to advance into the target lateral branch of the coronary sinus. We made a veno-venous loop, advancing the coronary guidewire through the middle cardiac vein to coronary sinus and then to superior vena cava. The guidewire then snared through the same left subclavian vein and exteriorized. Over this loop, the left ventricular lead of the CRT-D device was implanted successfully. This novel approach can be used to successfully implant the LV lead in difficult to implant situations, obviating the need for thoracotomy or other methods of LV lead implantation.

Objectives: Right ventricular (RV) pacing induces a left bundle branch block pattern on ECG and may promote heart failure. Patients with dual chamber pacemakers (DCPs) who present with progressive reduction in left ventricular ejection fraction (LVEF) secondary to RV pacing are candidates for cardiac resynchronization therapy (CRT). This study analyzes whether upgrading DCP to CRT with the additional implantation of a left ventricular (LV) lead improves LV function in patients with reduced LVEF following DCP implantation. Methods: Twenty-two patients (13 males) implanted with DCPs and a high RV pacing percentage (>90%) were evaluated in term of new-onset heart failure symptoms. The patients were enrolled in this retrospective single-center study after obvious causes for a reduced LVEF were excluded with echocardiography and coronary angiography. In all patients, DCPs were then upgraded to biventricular devices. LVEF was analyzed with a two-sided t-test. QRS duration and brain natriuretic peptide (BNP) levels were analyzed with the unpaired t-test. Results: LVEF declined after DCP implantation from 54±10% to 31±7%, and the mean QRS duration was 161±20 ms during RV pacing. NT-pro BNP levels were elevated (3365±11436 pmol/L). After upgrading to a biventricular device, a biventricular pacing percentage of 98.1±2% was achieved. QRS duration decreased to 108±16 ms and 106±20 ms after 1 and 6 months, respectively. There was a significant increase in LVEF to 38±8% and 41±11% and a decrease in NT-pro BNP levels to 3088±2326 pmol/L and 1860±1838 pmol/L at 1 and 6 months, respectively. Conclusion: Upgrading to CRT may be beneficial in patients with DCPs and heart failure induced by a high RV pacing percentage. [ABSTRACT FROM AUTHOR]

The combined use of an Amplatz guiding catheter and support catheter creates a progressively supportive rail to implant the left ventricular (LV) lead in difficult cardiac resynchronization therapy device implantation. We describe the case of a 32-year-old male with non-ischaemic cardiomyopathy, left bundle-branch block, and an LV ejection fraction of 30%, who was referred to our centre for a repeat attempt at an LV lead implant. Previously, the implanter had been unable to advance different guide catheters over the wire to the desired tributary of the coronary sinus (CS). At our centre, the CS was cannulated with a 6-Fr AL2 coronary guiding catheter. A 135-cm support catheter (Spectranetics Quick-Cross) was advanced via AL2 guiding over the 0.035 in. guide wire to the distal CS. The proximal luer fitting of the support catheter was cut and an inner sheath (Medtronic ATTAIN SELECT II) advanced over the support catheter into the CS. A 4-Fr over-the-wire LV lead was advanced through the inner sheath over a 0.014 in. percutaneous transluminal coronary angioplasty wire after removal of the support catheter. The use of a support catheter serves as rail for the placement of the inner sheath deep in the CS and facilitates implantation of the LV pacing lead. This technique is safe and easily applied.

Background: Cardiac resynchronization therapy (CRT) is now an established effective treatment for patients with advanced heart failure. One approach to improve CRT outcome may be determination of the degree of dsynchrony before CRT as a predictor for CRT response. Conversely, the focus may be on an improved positioning of CRT left ventricular (LV) lead. AIM of the study: We aimed at our study to define the rule of three-dimensional echocardiography in determining the optimal site of LV pacing lead. Patients and Methods: The current study was conducted on 30 patients with heart failure who had received CRT in Ain Shams University Hospitals in the period from 2012 to 2014. All patients were subjected to thorough history taking, complete general and local examination, conventional 2D echo and 3D echo analysis. The latest wall to reach the minimal volume was determined. The patients were classified after CRT insertion into group A with concordance between the delayed LV area and LV lead position and group B with discordance between them. Our patients were followed up for 6 months duration. Results: Our findings demonstrated that the response to CRT resulted in improvement of NYHA class (p-value 0.04), LV EF by 2D and 3D echocardiography (P value <0.001 for both) with significant increase in LV 3D SV (p value 0.001), and significant reduction of LA diameter (p-value 0.03), LVESD diameter, 2D and 2D LVESV (P value 0.026, 0.026 respectively), however there was no any statistically significant difference between both groups. Conclusions: No additional benefit of selecting LV lead position pre CRT insertion to be concordant with the latest myocardial segment in reaching the minimal systolic volume assessed by 3D echocardiography. [ABSTRACT FROM AUTHOR]

Roles of Q (q) Wave in Lead I and QRS Axis for Diagnosing Loss of LV Capture During CRT Introduction Loss of left ventricular (LV) capture may lead to deterioration of heart failure in patients with cardiac resynchronization therapy (CRT). Recognition of loss of LV capture in time is important in clinical practice. Methods and Results A total of 422 electrocardiograms were acquired and analyzed from 53 CRT patients at 8 different pacing settings (LV only, right ventricle [RV] only, biventricular [BV] pacing with LV preactivation of 60, 40, 20, and 0 milliseconds and RV preactivation of 20 and 40 milliseconds). A modified Ammann algorithm by adding a third step-presence of Q (q, or QS) wave-to the original 2-step Ammann algorithm and a QRS axis shift method were devised to identify the loss of LV capture. The accuracy of modified Ammann algorithm was significantly higher than that of Ammann algorithm (78.9% vs. 69.1%, P < 0.001). The accuracy of the axis shift method was 66.4%, which was significantly lower than the modified Ammann algorithm (P < 0.001) and similar to the original one (P = 0.412). However, in the ECGs with QRS axis shift, 96.8% were correctly classified. LV preactivation or simultaneous BV activation and LV lead positioned in nonposterior or noninferior wall could elevate the accuracies of the modified Ammann algorithm and the QRS axis shift method. Conclusions The accuracy of the modified Ammann algorithm is greatly improved. The QRS axis shift method can help diagnose LV capture. The LV preactivation, or simultaneous BV activation and LV lead positioned in nonposterior or noninferior wall can increase the diagnostic power of the modified Ammann algorithm and QRS axis shift method. [ABSTRACT FROM AUTHOR]

Background: Left ventricular (LV) lead implantation for cardiac resynchronization therapy (CRT) is associated with lead dislodgement rates ranging from 3% to 10%, and some implant approaches to prevent dislodgement may contribute to suboptimal CRT response. We report our early human experience with an LV lead with a side helix for active fixation to the coronary vein wall. Objectives: To assess the feasibility and safety of the Model 20066 LV lead and to evaluate the implant procedure. Methods: The Model 20066 is a 4-F bipolar steroid eluting lead that has a small exposed side helix and can be delivered using a guidewire or stylet. At the desired vein location, the lead body is rotated clockwise until the helix is fixated. This study was a single-arm, prospective, nonrandomized trial that enrolled 40 patients from 4 centers who met standard indications for CRT. Results: The lead was successfully implanted in 39 of 40 (98%) patients. In 38 of 40 (95%) patients, the implanters were successful at implanting at a predetermined target site. There were no Model 20066 LV lead dislodgements reported within 12 months of follow-up. The electrical performance of the tip and ring electrodes was stable through the 12-month follow-up visit and similar to other LV leads. Overall lead handling was rated as acceptable for all implants. Conclusion: This new LV lead specifically designed with an active fixation mechanism for stability and precise placement was successfully and safely deployed in the coronary vasculature. [Copyright &y& Elsevier]

Accurate 3D Navigation System for LV Lead Implant Introduction Cardiac resynchronization therapy implants entail significant radiation exposure for patients and physicians. A novel 3D electromagnetic cardiovascular navigation system (MediGuide™) was designed to superimpose the real-time location of sensors embedded in delivery tools on prerecorded coronary sinus (CS) venograms while adjusting for patient movement and variations in heart rate under different C-arm angulations. We studied the accuracy and efficacy of MediGuide™ in reducing radiation exposure during LV lead implants. Methods and Results Fluoroscopy durations and radiation exposures were measured in 6 canines undergoing both conventional and MediGuide™-guided LV lead implants. The in vivo accuracy of MediGuide™ was evaluated by obtaining CS venograms at 3 different C-arm angulations at 3 different heart rates and measuring the separation between the projected sensor icon of a MediGuide™ sensor-enabled guidewire and the encompassing branch on prerecorded venograms. Results Mediguide™-guided implants resulted in significant reductions in fluoroscopy time (52 ± 120 [median 6] vs 129 ± 118 [median 90] sec, P < 0.001) and radiation exposure (13.8 ± 32.4 [median 1.7] vs 49.2 ± 45.3 [median 27.2] μGym2, P = 0.03) compared to conventional implants. LV lead delivery time was not significantly different between the 2 implant techniques (P = 0.27). The mean separation between the projected guidewire sensor icon and its encompassing branch was 0.48 ± 0.94 (median 0.00) mm. System accuracy was not affected by variations in heart rate or C-arm angulations. Conclusion The novel 3D cardiovascular navigation system enabled accurate and reliable tracking of sensor-enabled tools at varying heart rates and C-arm angulations with minimal need for fluoroscopy guidance, significantly reducing fluoroscopy time and radiation exposure. [ABSTRACT FROM AUTHOR]

LV Lead Extraction and Reimplantation. Background: Early series of biventricular device removal have contained mostly younger cardiac venous (CV) left ventricular leads and few have reported on rates of successful reimplantation. Methods and Results: We performed a retrospective analysis of all patients referred to the Cleveland Clinic between February 2, 2001 and July 27, 2011 for removal of a biventricular device with a CV pacing lead for an infectious indication. A total of 173 patients were included. The median age of the CV leads was 22.3 months (interquartile range: 5.2-46.3 months). The complete procedural success rate for all leads was 97.7%, with the remaining 2.3% clinical successes. A total of 76.9% of CV leads were removed using simple traction alone with the remaining leads requiring the use of a laser-powered sheath. A total of 3.5% of leads required intervention (manual dissection or laser-powered dissection) within the coronary sinus (CS). Major complications occurred in 1.2% of patients. Minor complications occurred in 7.5% of patients, the majority of which were hematomas requiring drainage (6.9%). CV lead reimplantation was attempted in 107 patients of which 88 (82.8%) were successful. Conclusion: CV lead removal in patients with an infected biventricular device is associated with an extremely high procedural success rate and a low incidence of major complications. The use of a laser-powered sheath is necessary in roughly one-quarter of cases with a very small percentage requiring intervention within the CS. Reimplantation of CV leads is achievable in roughly 83% of patients, a figure lower than nationally quoted estimates for de novo implantations. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1213-1216, November 2012) [ABSTRACT FROM AUTHOR]

Aims The risk of contrast-induced nephropathy (CIN) with radiocontrast use during left ventricular (LV) lead placement for cardiac resynchronization therapy (CRT) is unknown. It is unclear as to whether minimizing contrast use impacts adequacy of LV lead placement. Methods and results A retrospective analysis was performed of all LV leads placed for CRT at Mayo Clinic, Rochester, MN from 16 March 2001 to 1 April 2009. The primary goal was to assess risk of CIN and adequacy of lead placement depending on the amount of contrast administered during CRT placement. Contrast-induced nephropathy was defined as a ≥25% increase in serum creatinine ≥48 h post-procedurally. Adequacy of lead placement was assessed in a blinded fashion by review of procedural fluoroscopic and post-procedural radiographic images. Eight hundred and twenty-two subjects were divided based on the amount of procedural contrast used into tertile 1 (<55 mL, 257 patients), tertile 2 (55–94 mL, 261 patients), and tertile 3 (≥95 mL, 304 patients). Contrast-induced nephropathy occurred in 5.4% of patients in tertile 1, 5.4% in tertile 2 and 11.8% in tertile 3 (P = 0.004). Among the tertiles, lead positioning was optimal in 95, 80 and 66%, respectively (P < 0.0001). Fluoroscopic time was 34 ± 23, 42 ± 26, and 48 ± 30 min in tertiles 1, 2, and 3 (P < 0.0001). Conclusion Risk of CIN with CRT implantations was substantial. Increased volume of radiocontrast used for LV lead placement was associated with substantially increased risk of CIN. Minimal contrast use was associated with decreased procedural times without adverse impact on adequacy of lead placement. [ABSTRACT FROM PUBLISHER]

Aims Left ventricular (LV) lead placement to the most delayed segment offers the greatest potential benefit to cardiac resynchronization therapy (CRT). We assessed the impact of interventricular (VV) optimization on acute changes in cardiac output (CO) in patients with and without LV pacing of the most delayed segment. Methods and results In 124 patients, the most delayed segment was defined by speckle tracking radial strain and the LV lead position by biplane fluoroscopy. Patients were classified as either a concordant (LV lead at latest site), adjacent (within one segment), or remote (two or more segments away) LV lead. Atrioventricular (AV) and VV delays were optimized by echocardiography. Cardiac output was measured non-invasively and a >20% increase in CO from baseline (intrinsic) defined acute response. Changes in CO in patients with concordant, adjacent, or remote LV leads were recorded following atrioventricular optimization alone (AV OPT) and after combined AV and VV optimization (AV/VV OPT). Compared with AV OPT pacing, AV/VV OPT produced a greater rise in CO (5.45 ± 1.1 vs. 5.76 ± 1.2 L/min, P< 0.001) and higher acute response rates (48.4 vs. 61.3%, P= 0.041). In adjacent patients, compared with AV OPT pacing, AV/VV OPT settings increased the response rate from 36.4 to 63.6% (P= 0.037). VV optimization had no effect on acute response rates in patients with remote (26.7 vs. 33.3%, P = 0.581) or concordant LV leads (65.6 vs. 72.1%, P = 0.438). Conclusion VV optimization overcomes some but not all of the deleterious effects of a suboptimal LV lead position. [ABSTRACT FROM PUBLISHER]

Left ventricular (LV) lead placement to the latest contracting area (concordant LV lead) is associated with better response to cardiac resynchronization therapy (CRT) compared to a discordant LV lead. However, the effect of the right ventricular (RV) lead site on CRT response is unclear. We investigated the relationship of the RV and LV lead positions on CRT response. In 131 CRT patients, the LV lead was positioned preferentially in a lateral or posterolateral vein and the RV lead to either the RV septum (RVS, n = 55) or RV apex (RVA, n = 76). The latest site of contraction was determined with two-dimensional speckle tracking radial strain imaging and patients had a concordant LV lead position if pacing the latest segment, and discordant if not. Response was defined as ≥15% reduction in LV end systolic volume (LVESV) at 6-month follow-up. There were no significant differences in mean reduction of LVESV at follow-up (RVS vs RVA: −23.3 ± 16% vs 22.1 ± 18%, P = 0.70) or rate of responders (58.2% vs 57.9%, P = 0.97) between the two groups. In patients with a concordant LV lead (n = 71), the response rate was significantly higher than those with a discordant lead (76.1% vs 36.7%, P < 0.001). There were no differences in outcomes in patients with a concordant or discordant LV lead according to the RV lead location. The extent of LV reverse remodeling following CRT is not related to the RV lead position, but is significantly higher in patients with a concordant LV lead. (PACE 2011; 34:467-474) [ABSTRACT FROM AUTHOR]

Purpose The aim of the current study was to evaluate the relationship between the site of latest mechanical activation as assessed with gated myocardial perfusion SPECT (GMPS), left ventricular (LV) lead position and response to cardiac resynchronization therapy (CRT). Methods The patient population consisted of consecutive patients with advanced heart failure in whom CRT was currently indicated. Before implantation, 2-D echocardiography and GMPS were performed. The echocardiography was performed to assess LV end-systolic volume (LVESV), LVend-diastolic volume (LVEDV) and LV ejection fraction (LVEF). The site of latest mechanical activation was assessed by phase analysis of GMPS studies and related to LV lead position on fluoroscopy. Echocardiography was repeated after 6 months of CRT. CRT response was defined as a decrease of Q15% in LVESV. Results Enrolled in the study were 90 patients (72% men, 1667±10 years) with advanced heart failure. In 52 patients (58%), the LV lead was positioned at the site of latest mechanical activation (concordant), and in 38 patients (42%) the LV lead was positioned outside the site of latest mechanical activation (discordant). CRT response was significantly more often documented in patients with a concordant LV lead position than in patients with a discordant LV lead position (79% vs. 26 %, p<0.01). After 6 months, patients with a concordant LV lead position showed significant improvement in LVEF, LVESV and LVEDV (p≤ 0.05), whereas patients with a discordant LV lead position showed no significant improvement in these variables. Conclusion Patients with a concordant LV lead position showed significant improvement in LV volumes and LV systolic function, whereas patients with a discordant LV lead position showed no significant improvements. [ABSTRACT FROM AUTHOR]

Background: Positioning the left ventricular lead at the optimal myocardial segment has been proposed to improve cardiac resynchronization therapy (CRT) response., Objectives: We performed a systematic review and network meta-analysis evaluating echocardiographic and clinical response delivered with different guidance modalities compared to conventional fluoroscopic positioning., Methods: Randomized trials with ≥6 months follow-up comparing any combination of imaging, electrical, hemodynamic, or fluoroscopic guidance were included. Imaging modalities were split whether one modality was used: cardiac magnetic resonance (CMR), speckle-tracking echocardiography (STE), single-photon emission computed tomography, cardiac computed tomography (CT), or a combination of these, defined as "multimodality imaging.", Results: Twelve studies were included (n = 1864). Pair-wise meta-analysis resulted in significant odds of reduction in left ventricular end-systolic volume (LVESV) >15% (odds ratio [OR] 1.50, 95% confidence interval [CI] 1.05-2.13, P = .025) and absolute reduction in LVESV (standardized mean difference [SMD] -0.25, 95% CI -0.43 to -0.08, P = .005) with guidance. CMR (OR 55.3, 95% CI 4.7-656.9, P = .002), electrical (OR 17.0, 95% CI 2.9-100, P = .002), multimodality imaging (OR 4.47, 95% CI 1.36-14.7, P = .014), and hemodynamic guidance (OR 1.29-28.0, P = .02) were significant in reducing LVESV >15%. Only STE demonstrated a significant reduction in absolute LVESV (SMD -0.38, 95% CI -0.68 to -0.09, P = .011]. CMR had the highest probability of improving clinical response (OR 17.9, 95% CI 5.14-62.5, P < .001)., Conclusion: Overall, guidance improves CRT outcomes. STE and multimodality imaging provided the most reliable evidence of efficacy. Wide CIs observed for results of CMR guidance suggest more powered studies are required before a clear ranking is possible., (© 2022 Heart Rhythm Society. Published by Elsevier Inc.)

The author discusses the research "Long-term pacing pulses reduce phrenic nerve stimulation in left ventricular pacing" by S Hjortshoj and others is this issue. The topics discussed include cardiac resynchronization therapy (CRT) in patients with left ventricular (LV) dysfunction, prevention of phrenic nerve stimulation in CRT, and LV epicardial pacing.

Abstract: The combined use of an Amplatz guiding catheter and support catheter creates a progressively supportive rail to implant the left ventricular (LV) lead in difficult cardiac resynchronization therapy device implantation. We describe the case of a 32-year-old male with non-ischaemic cardiomyopathy, left bundle-branch block, and an LV ejection fraction of 30%, who was referred to our centre for a repeat attempt at an LV lead implant. Previously, the implanter had been unable to advance different guide catheters over the wire to the desired tributary of the coronary sinus (CS). At our centre, the CS was cannulated with a 6-Fr AL2 coronary guiding catheter. A 135-cm support catheter (Spectranetics Quick-Cross) was advanced via AL2 guiding over the 0.035in. guide wire to the distal CS. The proximal luer fitting of the support catheter was cut and an inner sheath (Medtronic ATTAIN SELECT II) advanced over the support catheter into the CS. A 4-Fr over-the-wire LV lead was advanced through the inner sheath over a 0.014in. percutaneous transluminal coronary angioplasty wire after removal of the support catheter. The use of a support catheter serves as rail for the placement of the inner sheath deep in the CS and facilitates implantation of the LV pacing lead. This technique is safe and easily applied. [Copyright &y& Elsevier]

We reported a case that left ventricular (LV) lead with retained guidewire was used 6 years ago, but the LV lead was broken during 6 years of follow-up. Although the retained guidewire technique has already been abandoned, the long-term safety of retained guidewire lead appears to be an even greater concern. [ABSTRACT FROM AUTHOR]

Objectives: The authors aimed to evaluate the association of left ventricular (LV) lead location and long-term outcomes in MADIT-CRT (Multicenter Automatic Defibrillator Implantation With Cardiac Resynchronization Therapy)., Background: There is limited data on the association of lead location with long-term clinical outcomes in patients with cardiac resynchronization therapy with defibrillator (CRT-D)., Methods: The LV lead location was classified in 797 patients with CRT-D, in 569 patients with left bundle branch block (LBBB), in 228 patients with non-LBBB, and in 505 patients with an implantable cardioverter-defibrillator (ICD) only. Leads were classified into apical (n = 83) and non-apical (n = 486); with the non-apical LV leads further categorized into anterior (n = 99) and posterior/lateral (n = 387) within LBBB. All-cause mortality and heart failure (HF) events were assessed using Kaplan-Meier and Cox analyses., Results: In CRT-D patients with LBBB and posterior/lateral LV lead location, there was an association with a significant reduction in long-term all-cause mortality (hazard ratio [HR]: 0.54, 95% confidence interval [CI]: 0.37 to 0.79; p = 0.001), and HF events (HR: 0.44, 95% CI: 0.33 to 0.60; p < 0.001) compared to an ICD only, accompanied with better LV reverse remodeling. CRT-D patients with LBBB and an anterior LV lead location were shown to be associated with a significant reduction in HF events compared to an ICD only (anterior HR: 0.50, 95% CI: 0.30 to 0.82; p = 0.006); however, no association with mortality reduction was observed from CRT-D versus an ICD only. CRT-D was not associated with improved outcomes in non-LBBB patients, regardless of LV lead location., Conclusions: In mild HF patients with LBBB and an implanted CRT-D, lateral/posterior, and anterior LV lead locations are similarly associated with reduction in the risk of HF or death events compared to ICD alone. Mortality benefit derived from CRT-D is associated only with patients with lateral/posterior LV lead location. An apical LV lead location should be avoided due to the early risk of death whenever possible. (Multicenter Automatic Defibrillator Implantation With Cardiac Resynchronization Therapy [MADIT-CRT], NCT00180271; Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy Post Approval Registry [MADIT-CRT-PAR], NCT01294449; and MADIT-CRT Long-Term International Follow-Up Registry - Europe, NCT02060110)., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Introduction: Satisfactory left ventricular (LV) lead placement into the coronary sinus (CS) can be achieved in the majority of patients but there are still instances of acute failure most often due to anatomical differences, for example due to tortuous CS anatomy. Chronic LV lead misplacement and its delayed discovery is not a common scenario. It is unclear if chronic dual right ventricular pacing can hasten the progression of heart failure., Case Presentation: A 73-year-old lady presented to our cardiac centre with severe heart failure. She had non-ischaemic dilated cardiomyopathy with underlying left bundle branch block and a cardiac resynchronization therapy-defibrillator device in situ for the past decade. She also had a chronic pericardial effusion of unknown aetiology. Whilst the patient was being treated for acute heart failure, it was noted on patient telemetry that the QRS morphology for supposed bi-ventricular pacing was unusual. This led to a lateral chest radiograph and a CS venogram to be performed, both of which confirmed that the LV lead was in fact not in the CS. Plans were made to place a new LV lead but unfortunately the patient continued to clinically deteriorate despite maximal treatment and died before this could be performed., Discussion: It is only with thorough review of the electrocardiographic data and chest radiography that led to the discovery of chronic LV lead misplacement. This case illustrates the importance of expert review of radiographic imaging and electrocardiographic data in patients with implanted cardiac devices.