CI-452766-1 ABRUPT TORQUE TRANSFER OCCURS FREQUENTLY DURING CONDUCTION SYSTEM PACING INSERTION IN AN EX-VIVO MODEL

A fundamental challenge in conduction system pacing [CSP] is determining appropriate lead deployment. With either fixed core or stylet driven leads, the input number of turns may not match resultant rotations achieved by helix. To date, no validated ex-vivo experimental model has been developed to enable quantitative assessment ratio helix rotation. develop a quantitatively describe CSP tip tissue response curves. Sixty-four fresh (<48h) ovine right ventricular septa were excised. Four different leads (1 (A), 3 stylet-driven (B,C,D)) into septal myocardium using support via custom-engineered jig allowing control rotation and measurement Leads inserted 15 applied proximally on lead, with tissue-interface characteristics observed at each 90° increment high resolution photography. Output (helix) vs curves [RRC] assessed automated segmented linear regression. RRC models statistically analysed slope (to characterise output response) breakpoints abrupt torque transfer [AAT]). total 3840 observations ¼ turn proximal recorded. 16 repeated RRCs created for type. Mean across was 0.46 [95%CI 0.39, 0.52] implying muted compared rotations. events [ATT] during insertion (measured break-points RRC) 7.2 6.6, 7.7]. In 57.8% (37/64) insertions, there uncontrolled [uATT] where more than An examine relationship leads. Using robust sample size, this showed between yields an overall tip. However, insertion, are common, occurring half insertions. These findings clinical significance implanters be aware potential events, particularly when they uncontrolled. data suggest new designs required increase efficiency safety CSP.Tabled 1Slope breakpoint analysis curves.Lead TypeLead TypeMean Slope [95%CI]Mean # ATT per uATT [Range]Solid CoreLead A0.28 [0.15, 0.55]7.31 [6.08, 8.54]0.5 [0 3]Stylet DrivenLead B0.48 [0.37, 0.71]6.81 [5.57, 8.05]0.69 [ 0 C0.66 [0.55, 0.88]7.56 [6.50, 8.62]1.31 6]Stylet D0.45 [0.35, 0.64]7.18 [6.11, 8.26]0.86 2]ALL0.46 [0.39, 0.52]7.22 8.35]0.84 6]Table 1: shows that delivered substantially less Abrupt occur sudden changes observed, frequenty physiological Uncontrolled transmission occurs exceeds immediate rotation, indicating release build-up from lead. = Rotation Response Curve. Torque Transfer event change RRC. Events Helix > Open table tab