Search

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]

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]

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]

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]

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]

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]

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]

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.

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]