Libbus Imad, Tholakanahalli Venkatakrishna, Roukoz Henri, Knoper Ryan, Verma Varun, Isac Divya, Manicka Yatheendhar
Calyan Technologies, Saint Paul, MN, USA.
University of Minnesota, Minneapolis, MN, USA.
J Interv Card Electrophysiol. 2024 Mar 1. doi: 10.1007/s10840-024-01778-y.
Traditional cardiac pacemakers commonly have a range of complications related to the presence of intracardiac leads. A new class of extravascular and leadless pacemakers has recently emerged with the potential to mitigate these complications and expand access to cardiac pacing. The objective of this study is to evaluate the implantation, short-term chronic safety, and performance of a novel subxiphoidal extracardiac pacemaker.
Normal Yorkshire Cross swine (n = 16) were implanted with the subxiphoidal pacemaker. The pacemaker was inserted through a midline chest incision and clipped to the underside of the sternum, with the stimulation electrode placed on the anterior pericardium. Animals were chronically paced and followed for 90 days post-implant, with periodic measurement of pacing capture threshold (PCT) and electrode impedance.
All 16 animals were successfully implanted with the study device. At implant, a consistent average PCT of 2.2 ± 0.4 V at a pulse width of 1.0 ms was observed in all animals, with an average implant impedance of 648 ± 44 Ω. Chronic pacing was programmed at a rate of 60 bpm, an amplitude of 3.4 ± 0.7 V, and a pulse width of 1.0 ms. PCT rose to 4.6 ± 0.8 V at 14 days and stabilized; at 90 days, PCT was 3.8 ± 1.2 V and electrode impedance was 533 ± 105 Ω. All implanted animals completed the study with no clinically significant findings, no clinically significant abnormalities, and with no adverse events that affected animal welfare.
This study demonstrated the safety and feasibility of a novel subxiphoidal extracardiac pacemaker to deliver short-term chronic extravascular therapy. Further studies are required to assess the safety, feasibility, and long-term chronic pacing performance in human subjects.
传统心脏起搏器通常会出现一系列与心内导线存在相关的并发症。最近出现了一类新型的血管外无导线起搏器，有可能减轻这些并发症并扩大心脏起搏的可及性。本研究的目的是评估一种新型剑突下心外起搏器的植入情况、短期长期安全性及性能。
对16只正常的约克夏杂交猪植入剑突下心外起搏器。起搏器通过胸部正中切口插入并夹在胸骨下方，刺激电极置于心包前部。对动物进行长期起搏，并在植入后随访90天，定期测量起搏捕获阈值（PCT）和电极阻抗。
所有16只动物均成功植入研究装置。植入时，所有动物在脉宽为1.0毫秒时的平均PCT一致为2.2±0.4伏，平均植入阻抗为648±44Ω。长期起搏的程控参数为心率60次/分、幅度3.4±0.7伏、脉宽1.0毫秒。PCT在14天时升至4.6±0.8伏并稳定下来；90天时，PCT为3.8±1.2伏，电极阻抗为533±105Ω。所有植入动物均完成研究，无临床显著发现，无临床显著异常，也无影响动物福利的不良事件。
本研究证明了一种新型剑突下心外起搏器进行短期长期血管外治疗的安全性和可行性。需要进一步研究来评估其在人类受试者中的安全性、可行性和长期起搏性能。
