Gillis A M, Rothschild J M, Hillier K, Fudge W, Kieser T M, Maitland A
Division of Cardiology, University of Calgary, Alberta, Canada.
Pacing Clin Electrophysiol. 1993 May;16(5 Pt 1):964-70. doi: 10.1111/j.1540-8159.1993.tb04569.x.
Differences in acute and chronic pacing thresholds were compared in patients receiving either the Medtronic Model 4004 steroid-eluting lead or the Medtronic Model 4012 microporous platinum lead. Patients (n = 35) were randomized at the time of implant to receive either a steroid-eluting (n = 17) or a microporous (n = 18) lead. Pacing thresholds were determined within 24 hours and at 2, 4, 6, 12, 24, and 52 weeks postimplant. By 2 weeks postimplant, pacing thresholds measured at 0.8, 1.6, 2.5, 3.3, and 4.2 V were significantly lower in the steroid lead group compared to the microporous lead group (P < 0.05). At 24 weeks, the voltage threshold at 0.3 msec was 0.8 V in 88% of patients with a steroid lead whereas this threshold was only observed in 33% of patients with the microporous lead (P < 0.01). At 52 weeks the pacing energy measured at 1.6 V, twice pulse duration threshold, was significantly lower in the steroid lead group (0.81 +/- 0.59 microJ) compared to the microporous lead group (1.25 +/- 0.60 microJ, P < 0.05). Thirteen patients in the steroid lead group and 9 patients in the microporous lead group have been programmed at a pulse amplitude of 1.6 V since the 24-week follow-up visit. These patients have been followed for a minimum of 6 months without documented failure to capture. This study shows that pacemaker/lead systems with stable chronic low thresholds can be safely programmed to low pulse amplitude settings. This practice will prolong the longevity of pulse generators.
对接受美敦力4004型类固醇洗脱导线或美敦力4012型微孔铂导线的患者的急性和慢性起搏阈值差异进行了比较。患者（n = 35）在植入时随机分为接受类固醇洗脱导线组（n = 17）或微孔导线组（n = 18）。在植入后24小时内以及植入后2、4、6、12、24和52周测定起搏阈值。到植入后2周时，与微孔导线组相比，类固醇导线组在0.8、1.6、2.5、3.3和4.2 V时测量的起搏阈值显著更低（P < 0.05）。在24周时，对于使用类固醇导线的患者，88%在0.3毫秒时的电压阈值为0.8 V，而使用微孔导线的患者中只有33%观察到该阈值（P < 0.01）。在52周时，与微孔导线组（1.25 +/- 0.60微焦，P < 0.05）相比，类固醇导线组在1.6 V（两倍脉冲持续时间阈值）时测量的起搏能量显著更低（0.81 +/- 0.59微焦）。自24周随访就诊以来，类固醇导线组有13名患者和微孔导线组有9名患者已将脉冲幅度编程为1.6 V。这些患者已随访至少6个月，无捕获失败记录。本研究表明，具有稳定慢性低阈值的起搏器/导线系统可安全地编程为低脉冲幅度设置。这种做法将延长脉冲发生器的使用寿命。
