Effect of capacitor size and pathway resistance on defibrillation threshold for implantable defibrillators.
Effect of capacitor size and pathway resistance on defibrillation threshold for implantable defibrillators.
复制标题
电容器尺寸和通路电阻对植入式除颤器除颤阈值的影响。
DOI：
10.1161/01.cir.90.4.1840
复制
发表时间：
1994
期刊：
影响因子：
37.8
通讯作者：
S. Raissi
中科院分区：
文献类型：
--
作者：
C. Swerdlow;R. Kass;P. Chen;C. Hwang;S. Raissi
背景
植入式除颤器使用的截断指数脉冲的时间常数由输出电容器尺寸和除颤路径电阻决定。最佳电容器尺寸未知。
方法和结果
本研究比较了使用心外膜电极（15 名患者）或四种经静脉电极配置之一（52 名患者）的 67 名患者植入心律转复除颤器时标准 120 微法电容器 (DFT120) 和较小的 60 微法电容器 (DFT60) 的除颤阈值 (DFT)。对使用单相脉冲的 44 条除颤路径和使用双相脉冲的 53 条路径进行了 DFT60 和 DFT120 的配对比较。使用倾斜度为 65% 的截断指数脉冲。所有电极配置的汇总数据显示通路电阻与存储能量 DFT60 与 DFT120 的比率之间存在显着的负相关（单相脉冲：r = .75，P = .0001；双相脉冲：r = .68，P = .0001）。来自所有电极配置的数据形成一个连续体，其中 120 微法电容器更适合低电阻路径，60 微法电容器更适合高电阻路径。对于电阻 < 或 = 40 Ω 的通路，120 microF 电容器的适度优势主要应用于低 DFT 的通路：单相脉冲为 8.2 +/- 6.1 与 9.6 +/- 5.4 J (P = .001)，双相脉冲为 4.1 +/- 2.8 与 5.1 +/- 3.1 J (P < .02)。对于电阻 > 或 = 61 Ω 的通路，60 µF 电容器的更大优势适用于具有较高 DFT 的通路：单相脉冲为 12.4 +/- 4.3 与 23.1 +/- 6.4 J (P = .0001)，双相脉冲为 8.5 +/- 4.9 与 12.5 +/- 6.4 J (P = .0001)脉冲。对于使用单相 120-microF 脉冲的通路，相对于使用 60-microF 脉冲的 95% 的通路。同样，使用双相 120 µF 电容器的 48% 路径的 DFT < 或 = 10 J，而使用 60 µF 脉冲的该比例为 83%。
结论
与传统的 120μF 电容器相比，60μF 电容器对于低电阻通路具有临床上不显着的较高 DFT，而对于高电阻通路具有临床上重要的较低 DFT。最佳电容与临床除颤路径和波形的路径电阻成反比。
BACKGROUND
The time constant of truncated exponential pulses used with implantable defibrillators is determined by the output capacitor size and defibrillation pathway resistance. The optimal capacitor size is unknown.
METHODS AND RESULTS
This study compared defibrillation threshold (DFT) for standard 120-microF capacitors (DFT120) and smaller 60-microF capacitors (DFT60) at implantation of cardioverter-defibrillators in 67 patients using epicardial electrodes (15 patients) or one of four transvenous electrode configurations (52 patients). Paired comparisons of DFT60 and DFT120 were made for 44 defibrillation pathways using monophasic pulses and for 53 pathways using biphasic pulses. Truncated exponential pulses with 65% tilt were used. Pooled data from all electrode configurations showed a significant inverse correlation between pathway resistance and the ratio of stored energy DFT60 to DFT120 (monophasic pulses: r = .75, P = .0001; biphasic pulses: r = .68, P = .0001). Data from all electrode configurations formed a continuum with 120-microF capacitors superior for low-resistance pathways and 60-microF capacitors superior for high-resistance pathways. For pathways with resistance < or = 40 omega, the modest advantage of 120-microF capacitors applied primarily to pathways with low DFTs: 8.2 +/- 6.1 versus 9.6 +/- 5.4 J (P = .001) for monophasic pulses and 4.1 +/- 2.8 versus 5.1 +/- 3.1 J (P < .02) for biphasic pulses. The greater advantage of 60-microF capacitors for pathways with resistance > or = 61 omega applied to pathways with higher DFTs: 12.4 +/- 4.3 versus 23.1 +/- 6.4 J (P = .0001) for monophasic pulses and 8.5 +/- 4.9 versus 12.5 +/- 6.4 J (P = .0001) for biphasic pulses. For pathways using monophasic 120-microF pulses versus 95% for 60-microF pulses. Similarly, the DFT was < or = 10 J for 48% of pathways using biphasic 120-microF capacitors versus 83% for 60-microF pulses.
CONCLUSIONS
In comparison with conventional 120-microF capacitors, 60-microF capacitors had clinically insignificant higher DFTs for low-resistance pathways and clinically important lower DFTs for high-resistance pathways. Optimal capacitance is inversely related to pathway resistance for clinical defibrillation pathways and waveforms.
使用两种不同的临床可用系统对顺序脉冲和单脉冲除颤进行前瞻性比较。
影响因子：
24
作者：
Bardy,GH;Ivey,TD;Allen,MD;Johnson,G;Greene,HL
通讯作者：
Greene,HL