{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T09:40:37Z","timestamp":1785404437855,"version":"3.56.0"},"posted":{"date-parts":[[2025,11,26]]},"group-title":"Bioengineering","reference-count":16,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2025,11,26]],"date-time":"2025-11-26T00:00:00Z","timestamp":1764115200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.biorxiv.org\/about\/FAQ#license"}],"funder":[{"DOI":"10.13039\/100000050","name":"National Heart, Lung, And Blood Institute","doi-asserted-by":"crossref","award":["R01HL128752"],"award-info":[{"award-number":["R01HL128752"]}],"id":[{"id":"10.13039\/100000050","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100000050","name":"National Heart, Lung, And Blood Institute","doi-asserted-by":"crossref","award":["R21HL156039"],"award-info":[{"award-number":["R21HL156039"]}],"id":[{"id":"10.13039\/100000050","id-type":"DOI","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/035m9ft70","id-type":"ROR","asserted-by":"publisher"}]},{"award":["23CDA1057448"],"award-info":[{"award-number":["23CDA1057448"]}],"id":[{"id":"https:\/\/ror.org\/013kjyp64","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2025,11,26]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>Lumenless and stylet-driven leads used for left bundle branch area pacing differ in design and have a significant implantation learning curve. While prior studies examined longer helices for deep septal pacing, the influence of other design variables remains unclear.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Objective<\/jats:title>\n                  <jats:p>To evaluate how helix design and axial force affect interventricular septum insertion efficacy.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>Rigid leads were developed using helical coils with variable outer diameter, number of turns and pitch. Porcine septa (n=16) were clamped perpendicularly for insertion using an optimized rotation-response system. Axial force simulating lumenless (30g) or stylet-driven (60g) leads was applied, and a fixed number of rotations were delivered at a constant rate. Each helix design (n=8) was tested 3x per axial force at three septal sites. Insertion depth, muscle-torque and visual feedback were recorded. Insertion was successful if depth exceeded coil length without surface entanglement. Effects of design factors were compared.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>At 30g, more helix turns significantly improved insertion success (P=0.04), while fewer turns frequently produced entangled failure (P=0.04) marked by high torque variability (P&lt;0.001). Smaller-pitch helices trended toward higher torque and success, whereas larger pitch achieved greater depth (P=0.05). Larger outer diameters also trended toward higher torque and improved success at 30g. At 60g the influence of helix design variable diminished and consistently yielded higher than at 30g.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Conclusion<\/jats:title>\n                  <jats:p>An optimized lead rotation-to-translation system elucidates how helix geometry and axial force interact during septal insertion. These interactions are explainable using an intuitive mechanical framework which is helpful for optimizing lead design.<\/jats:p>\n                <\/jats:sec>","DOI":"10.1101\/2025.11.25.690583","type":"posted-content","created":{"date-parts":[[2025,11,27]],"date-time":"2025-11-27T04:25:13Z","timestamp":1764217513000},"source":"Crossref","is-referenced-by-count":0,"title":["Effect of Lead Body and Helix Design Variables on Implantation Success, Insertion Depth, and Muscle Torque in Left Bundle Branch Area: Insights from An Ex-Vivo Porcine Model"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9917-3539","authenticated-orcid":false,"given":"Ankur R.","family":"Shah","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alex","family":"Puccio","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kyoichiro","family":"Yazaki","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Emmanuel","family":"Offei","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martha Sofia Ruiz","family":"Castilo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Surachat","family":"Jaroonpipatkul","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ava Yaktaeian","family":"Vaziri","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6232-2633","authenticated-orcid":false,"given":"Muhammad S.","family":"Khan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ravi","family":"Ranjan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robert","family":"Hitchcock","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Derek J.","family":"Dosdall","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2025112801350549000_2025.11.25.690583v1.1","first-page":"225","article-title":"Greatbatch W: Two years\u2019 clinical experience with the implantable pacemaker for complete heart block","volume":"43","year":"1963","journal-title":"Dis Chest Elsevier"},{"key":"2025112801350549000_2025.11.25.690583v1.2","doi-asserted-by":"crossref","first-page":"1232","DOI":"10.1111\/pace.12461","article-title":"McVENES R: The electrode-tissue interface: The revolutionary role of steroid-elution","volume":"37","year":"2014","journal-title":"Pacing and Clinical Electrophysiology Wiley Online Library"},{"key":"2025112801350549000_2025.11.25.690583v1.3","first-page":"147","article-title":"Alternate sites of permanent cardiac pacing: A randomized study of novel technology","volume":"45","year":"2004","journal-title":"Hellenic J Cardiol"},{"key":"2025112801350549000_2025.11.25.690583v1.4","doi-asserted-by":"publisher","DOI":"10.1093\/europace\/euaf050"},{"key":"2025112801350549000_2025.11.25.690583v1.5","first-page":"1208","volume-title":"EHRA clinical consensus statement on conduction system pacing implantation: endorsed by the Asia Pacific Heart Rhythm Society (APHRS), Canadian Heart Rhythm Society (CHRS), and Latin American Heart Rhythm Society (LAHRS)","volume":"25","year":"2023"},{"key":"2025112801350549000_2025.11.25.690583v1.6","doi-asserted-by":"crossref","unstructured":"Sritharan A , Kozhuharov N , Masson N , Bakelants E , Valiton V , Burri H: Procedural outcome and follow-up of stylet-driven leads compared with lumenless leads for left bundle branch area pacing. 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