Vector Selection of a Quadripolar Left Ventricular Pacing Lead Affects Acute Hemodynamic Response to Cardiac Resynchronization Therapy: A Randomized Cross-Over Trial

Abstract

BackgroundA suboptimal left ventricular (LV) pacing site may account for non-responsiveness of patients to cardiac resynchronization therapy (CRT). The vector selection of a novel quadripolar LV pacing lead, which was mainly developed to overcome technical issues with stimulation thresholds and phrenic nerve capture, may affect hemodynamic response, and was therefore assessed in this study. (German Clinical Trials Register DRKS00000573).Methods and ResultsHemodynamic effects of a total of 145 LVPCs (9.1 per patient) of CRT devices with a quadripolar LV lead (Quartet™, St. Jude Medical) were assessed in 16/20 consecutive patients by invasive measurement of LV+dP/dtmax at an invasively optimized AV-interval in random order. Optimal (worst) LVPCs per patient were identified as those with maximal (minimal) %change in LV+dP/dtmax (%ΔLV+dP/dtmax) as compared to a preceding baseline. LV+dP/dtmax significantly increased in all 145 LVPCs (p<0.0001 compared to baseline) with significant intraindividual differences between LVPCs (p<0.0001). Overall, CRT acutely augmented %ΔLV+dP/dtmax by 31.3% (95% CI 24%–39%) in the optimal, by 21.3% (95% CI: 15%–27%) in the worst and by 28.2% (95% CI: 21%–36%) in a default distal LVPC. This resulted in an absolute additional acute increase in %ΔLV+dP/dtmax of 10.0% (95% CI: 7%–13%) of the optimal when compared to the worst (p<0.0001), and of 3.1% (95% CI: 1%–5%) of the optimal when compared to the default distal LVPC (p<0.001). Optimal LVPCs were not programmable with a standard bipolar lead in 44% (7/16) of patients.ConclusionThe pacing configuration of a quadripolar LV lead determinates acute hemodynamic response. Pacing in the individually optimized configuration gives rise to an additional absolute 10% increase in %ΔLV+dP/dtmax when comparing optimal and worst vectors.

Effectiveness and Reliability of Selected Site Pacing for Avoidance of Phrenic Nerve Stimulation in CRT Patients with Quadripolar LV Leads: The EffaceQ Study

“…Successful switch to a quadripolar LV lead as second‐line option after unsatisfactory bipolar lead implant attempt was proposed in a small sample study when bipolar leads had caused unsatisfactory results during CRT implantation . Additional benefit may arise from a hemodynamic point of view, as switching LV pacing sites on a quadripolar lead has been shown to acutely influence hemodynamic response to CRT with a difference up to 10% of acute change in contractility …”

“…18 Additional benefit may arise from a hemodynamic point of view, as switching LV pacing sites on a quadripolar lead has been shown to acutely influence hemodynamic response to CRT with a difference up to 10% of acute change in contractility. 19 With promising data from smaller series published, the EffaceQ study presented here was performed to investigate the efficacy (pacing threshold, freedom from phrenic nerve pacing) and reliability (stability of measures over time) of the Quartet TM lead in CRT patients.…”

Optimizing cardiac resynchronization therapy to minimize ATP consumption heterogeneity throughout the left ventricle: A simulation analysis using a canine heart failure model

“…Indeed, clinical studies have shown that there is a significant interindividual variability in the location of the optimal LV pacing site. 15-17 The significant interindividual variability in the location of the optimal LV pacing sites found in these clinical studies is due to the fact that a significant percentage of patients had ischemic cardiomyopathy (25%, 56% and 36% in the studies by Asbach et al, 15 Khan et al, 16 and Duckett et al, 17 respectively); the location of scar tissue influences the location of the optimal CRT pacing site. 16 The image-based simulation approach to CRT optimization presented here could be applied to each patient heart, building a personalized model (with ischemic cardiomyopathy also accounted for, should there be any) to be used in determining the optimal LV pacing site (either epi- or endocardial) in a patient-specific manner.…”

Left Ventricular Three‐Dimensional Quadripolar Lead Acute Clinical Study: The LILAC Study

“…It may offer the implanter the option of stability and good pacing capture without repositioning the lead at implant or during follow‐up. Finally, it is also conceivable that a better hemodynamic response may be achieved with multipolar leads . Coronary veins typically taper with smaller diameters in the distal or apical regions in comparison to larger diameters in more proximal or mid to basal regions.…”

“…Finally, it is also conceivable that a better hemodynamic response may be achieved with multipolar leads. [11][12][13][14][15][16][17] Coronary veins typically taper with smaller diameters in the distal or apical regions in comparison to larger diameters in more proximal or mid to basal regions. Because of the diameter disparity, it is often more difficult to achieve myocardial contact and, therefore, acceptable pacing thresholds in mid-to-basal regions where the best hemodynamic response could be achieved.…”