Of these implants, 99% of the Quadra and 95% of the Bipolar patients had de novo LV leads, respectively.
For this analysis, LV pacing leads that were positioned in the basal or mid-region of the LV were included and LV leads positioned at the cardiac apex were excluded from further analysis.
Several LV leads offer cathodal programmability and thus the ability to change pacing vector if conventional bipolar LV pacing is not satisfactory.
Direct injection of the plasmid, together with a normalisation plasmid expressing Renilla luciferase, into the free wall of the RV and LV leads to transfection of only cardiomyocytes.
Pre-shaped or linear, bipolar or unipolar LV leads of different manufacturers were used, according to the anatomy of each patient.
Despite continuous innovations and technological improvement of the delivery systems, guidewires, and LV leads, ∼10% of the implantation attempts still fail.
A total of 117 patients were implanted with the Quartet™ 1458Q model LV lead and corresponding Quadra CRT-D device (Promote™ Q, Unify Quadra™ from St . Jude Medical, and 81 patients were implanted with bipolar LV leads from four different manufacturers and corresponding CRT-D pulse generators.
Recently, it was shown that targeted placement of the LV pacing lead to the site of latest mechanical activation as elucidated by STE was associated with favourable reverse remodelling, fewer repeat hospitalizations, and improved functional capacity compared to patients with standard placement of LV leads [ 41].
Techniques for overcoming PNS include reducing the LV pacing output, repositioning the LV lead, surgical placement of an epicardial LV lead, or turning off LV pacing altogether.
The primary endpoint of this analysis was prospectively defined as the comparison of the combined hospitalization rate for HF hospitalization or LV lead-related surgical revision in the two LV lead groups.
