{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,11]],"date-time":"2025-11-11T22:20:21Z","timestamp":1762899621956,"version":"3.37.3"},"reference-count":9,"publisher":"Wiley","issue":"12","license":[{"start":{"date-parts":[[2018,11,11]],"date-time":"2018-11-11T00:00:00Z","timestamp":1541894400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Pacing Clinical Electrophis"],"published-print":{"date-parts":[[2018,12]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background<\/jats:title><jats:p>Today, there is no manufacturer\u2010supplied retrieval tool for the Micra\u2122 pacemaker (Medtronic, Minneapolis, MN, USA); therefore, off\u2010the\u2010shelf catheters have been employed for retrievals. The proximal retrieval feature of the Micra\u2122 can be snared and the device is then retracted from the myocardium, pulling the device through the tricuspid valve. This study characterizes the potential risks of Micra\u2122 nitinol tine engagement with the tricuspid sub\u2010valvular apparatus.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Fresh human hearts nonviable for transplant (<jats:italic>n<\/jats:italic>\u00a0=\u00a010) were obtained from our regional organ procurement agency (LifeSource, Minneapolis, MN, USA). Micra\u2122 fixation tines were affixed to a linear force transducer. Tines were then engaged in tricuspid chordae tendineae to conduct a constant velocity tensile test. Each test was run until tines disengaged from the chordae tendineae or until they released from the valve apparatus. Subsequently, biomechanical failure properties of the valve apparatus and isolated chordae tendineae were determined using a series of uniaxial tensile tests.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>There were no chordal ruptures observed during our Micra\u2122 tine extraction testing. Chordal failure required 15.0 times the force of extracting a single engaged tine, and 9.0 times the force of extracting two engaged tines. The uniaxial stresses required for isolated chordal failure averaged 17.4\u00a0N\/mm<jats:sup>2<\/jats:sup>; failure strains exceeded 150% resting chordal length.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>The forces required to rupture tricuspid chordae tendineae significantly exceeded the forces potentially imposed on the chordae during Micra\u2122 device retrievals. We conclude that the fixation tines of the Micra\u2122 device are unlikely to damage the tricuspid apparatus during either implant or retrieval.<\/jats:p><\/jats:sec>","DOI":"10.1111\/pace.13529","type":"journal-article","created":{"date-parts":[[2018,10,20]],"date-time":"2018-10-20T07:45:35Z","timestamp":1540021535000},"page":"1606-1610","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["The fixation tines of the Micra\u2122 leadless pacemaker are atraumatic to the tricuspid valve"],"prefix":"10.1111","volume":"41","author":[{"given":"Alexander R.","family":"Mattson","sequence":"first","affiliation":[{"name":"Department of Biomedical Engineering University of Minnesota  Minneapolis MN USA"},{"name":"Department of Surgery University of Minnesota  Minneapolis MN USA"},{"name":"Institute for Engineering in Medicine University of Minnesota  Minneapolis MN USA"},{"name":"Medtronic  Mounds View MN USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jorge D.","family":"Zhingre Sanchez","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering University of Minnesota  Minneapolis MN USA"},{"name":"Department of Surgery University of Minnesota  Minneapolis MN USA"},{"name":"Institute for Engineering in Medicine University of Minnesota  Minneapolis MN USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7661-352X","authenticated-orcid":false,"given":"Paul A.","family":"Iaizzo","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering University of Minnesota  Minneapolis MN USA"},{"name":"Department of Surgery University of Minnesota  Minneapolis MN USA"},{"name":"Institute for Engineering in Medicine University of Minnesota  Minneapolis MN USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2018,11,11]]},"reference":[{"key":"e_1_2_8_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.hrthm.2017.05.017"},{"key":"e_1_2_8_3_1","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCEP.116.004626"},{"key":"e_1_2_8_4_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.hrthm.2017.07.004"},{"key":"e_1_2_8_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.hrthm.2018.02.008"},{"key":"e_1_2_8_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.hrthm.2017.07.015"},{"key":"e_1_2_8_7_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.hrcr.2017.11.014"},{"key":"e_1_2_8_8_1","doi-asserted-by":"publisher","DOI":"10.1093\/europace\/euv444"},{"key":"e_1_2_8_9_1","doi-asserted-by":"publisher","DOI":"10.15420\/aer.2017:16:1"},{"key":"e_1_2_8_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0003-4975(00)01977-9"}],"container-title":["Pacing and Clinical Electrophysiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1111%2Fpace.13529","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/pace.13529","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,14]],"date-time":"2023-09-14T04:33:57Z","timestamp":1694666037000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/pace.13529"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,11,11]]},"references-count":9,"journal-issue":{"issue":"12","published-print":{"date-parts":[[2018,12]]}},"alternative-id":["10.1111\/pace.13529"],"URL":"https:\/\/doi.org\/10.1111\/pace.13529","archive":["Portico"],"relation":{},"ISSN":["0147-8389","1540-8159"],"issn-type":[{"type":"print","value":"0147-8389"},{"type":"electronic","value":"1540-8159"}],"subject":[],"published":{"date-parts":[[2018,11,11]]},"assertion":[{"value":"2018-06-12","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2018-10-03","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2018-11-11","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}