Lapuerta Irigoyen J A, Valverde Andre I, Vigil Escalera P, Vasserot Gonzalez M
Cabuenes Hospital, Gijon, Spain.
J Atr Fibrillation. 2016 Aug 31;9(2):1386. doi: 10.4022/jafib.1386. eCollection 2016 Aug-Sep.
The AcapConfirm™ feature available with the Zephyr pacemaker family (St. Jude Medical) is designed for monitoring patient's atrial capture threshold periodically, and automatically adjusting the atrial pulse amplitude. Previous studies showed a relative low proportion of patients at three months follow-up with recommended automatic atrial capture after the AcapConfirm™ viability test. The purpose of the present study is to evaluate the effect of inter electrode distance on the viability of the AcapConfirm™ algorithm. 132 patients (66 woman and 86 men; 71, 08 ± 8, 04 years old) were enrolled into this prospective evaluation. Sixty six bipolar leads (models 1882 (54p) and LPA1200M (12p)) with an inter electrode distance of 10 mm (Group A) were compared with sixty six bipolar leads (model 1999) with an inter electrode distance of 1,1mm (Group B). Set-up test AcapConfirm viability and manual step-down atrial threshold test as well as automatic threshold testing by AcapConfirm™ were performed at 3 months after implantation. A positive viability of the AcapConfirm™ algorithm was much lower in Group B (37, 9%; 95% confidence interval, 10, 3% - 65, 4%) versus thirty two patients (48, 5%; 95% confidence interval, 20, 9% - 76%) in Group A. However, the difference was not statistically significant (χ2=1, 51; p=0, 33). The most frequent reason to reject the AcapConfirm activation was a too small evoked response to polarization ratio (N9).At 3 months, threshold results from the AcapConfirm™ positive test were: 0, 53 ± 0, 13 V in Group B versus 0, 67 ± 0, 18 V in Group A (p< 0, 01). The differences between automatic and manual measurements were ≤0.25V in all patients. We observed that a short inter electrode distance (1,1mm) is more likely correlated with a lower frequency of AcapConfirm™ viability and threshold that a standard inter electrode distance (10mm). A small evoked response to polarization ratio was the most common cause of a negative test of AcapConfirm™ viability.
圣犹达医疗公司的Zephyr起搏器系列所具备的AcapConfirm™功能旨在定期监测患者的心房捕捉阈值，并自动调整心房脉冲幅度。先前的研究表明，在AcapConfirm™可行性测试后三个月随访时，达到推荐的自动心房捕捉的患者比例相对较低。本研究的目的是评估电极间距对AcapConfirm™算法可行性的影响。132例患者（66例女性和86例男性；年龄71.08±8.04岁）被纳入这项前瞻性评估。将66根电极间距为10毫米的双极导联（型号1882（54根）和LPA1200M（12根））（A组）与66根电极间距为1.1毫米的双极导联（型号1999）（B组）进行比较。在植入后3个月进行AcapConfirm可行性设置测试、手动逐步降低心房阈值测试以及AcapConfirm™自动阈值测试。AcapConfirm™算法的可行性在B组中低得多（37.9%；95%置信区间，10.3%-65.4%），而A组有32例患者（48.5%；95%置信区间，20.9%-76%）。然而，差异无统计学意义（χ2=1.51；p=0.33）。拒绝激活AcapConfirm的最常见原因是极化率诱发反应过小（N9）。在3个月时，AcapConfirm™阳性测试的阈值结果为：B组为0.53±0.13伏，A组为0.67±0.18伏（p<0.01）。所有患者自动测量和手动测量之间的差异≤0.25伏。我们观察到，与标准电极间距（10毫米）相比，较短的电极间距（1.1毫米）更有可能与AcapConfirm™可行性和阈值的较低频率相关。对极化率的小诱发反应是AcapConfirm™可行性测试呈阴性的最常见原因。
