Department of Cardiology, Medical Centre, Hungarian Defence Forces, Budapest, Hungary.
Department of Cardiology, University Hospital Frankfurt, Goethe University, Frankfurt, Germany.
J Cardiovasc Electrophysiol. 2018 Dec;29(12):1690-1696. doi: 10.1111/jce.13729. Epub 2018 Sep 25.
The Micra Transcatheter Pacing System provides a rate adaptive pacing using an individually programmable three-axis accelerometer. We evaluated the short- and mid-term performance of the Micra activity sensor by testing all three available activity vectors during the exercise tests.
Implantation and follow-up data were prospectively collected from the patients undergoing Micra implantation at our institution. Patients underwent a 5-minute exercise test for each vector at predischarge (initial testing) and at scheduled in-office visits (repeat testing). On the basis of measurements of activity counts during the test, vectors were categorized to be adequate (excellent or acceptable) or poor. A total of 278 tests with 818 vector measurements were analyzed in 51 patients during follow-up (median duration was 18 months). Initial testing revealed the adequate quality of the nominal Vector 1 in 74.5% of the patients. Upon repeated testing at subsequent in-office visits, Vectors 1 and 3 were comparable (adequate quality in 64.7% vs 68.6% of the patients; P = 0.65) but better compared with Vector 2 (51.0%; P = 0.10 vs Vector 1, P = 0.01 vs Vector 3). In a subgroup of 45 patients programmed to VVIR mode, Vector 1 was selected in 46.7% of the patients after the initial test (Vector 2, 8.9%; Vector 3, 44.4%). Vector change was performed in 10 patients (22.2%) following repeated tests within 3 months of postimplantation.
The three-axis accelerometer-based rate adaptive pacing feature proved to be feasible after manual selection of an adequate activity vector. Vector testing in Micra patients with chronotropic incompetence appears to be beneficial compared with the use of nominal Vector 1.
Micra 经导管起搏系统采用个体可程控三轴加速度计提供频率适应性起搏。我们通过在运动测试中测试所有三个可用的活动向量来评估 Micra 活动传感器的短期和中期性能。
在我们的机构中，前瞻性地收集了接受 Micra 植入的患者的植入和随访数据。患者在出院前（初始测试）和预定的门诊就诊时（重复测试）进行了 5 分钟的每个向量的运动测试。根据测试过程中的活动计数测量，将向量分类为充足（优秀或可接受）或不足。在 51 名患者的随访期间（中位随访时间为 18 个月），共进行了 278 次测试，共进行了 818 次向量测量。在初始测试中，74.5%的患者的标称向量 1 质量充足。在随后的门诊就诊时重复测试时，向量 1 和 3 相当（64.7%和 68.6%的患者质量充足；P=0.65），但优于向量 2（51.0%；P=0.10 与向量 1，P=0.01 与向量 3）。在编程为 VVIR 模式的 45 名患者亚组中，初始测试后有 46.7%的患者选择向量 1（向量 2，8.9%；向量 3，44.4%）。在植入后 3 个月内重复测试后，对 10 名患者（22.2%）进行了向量更换。
在手动选择充足的活动向量后，基于三轴加速度计的频率适应性起搏功能被证明是可行的。与使用标称向量 1 相比，在心动过缓功能不全的 Micra 患者中进行向量测试似乎是有益的。
