Optimizing Defibrillation Through Improved Waveforms
Optimizing Defibrillation Through Improved Waveforms
复制标题
通过改进波形优化除颤
DOI：
--
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
G. Breithardt
中科院分区：
文献类型：
--
作者：
M. Block;G. Breithardt
如果电流使大多数非同步化的心肌细胞去极化，则实现心脏的除颤。作为时间的函数描述的所施加的电流或相应的电压称为波形。在起搏中，为了刺激靠近电极的心肌细胞，需要相对较低的电压持续相对较短的持续时间。然而，在除颤中，需要大约100倍的高电压，并通过使用电容器来实现。电容器在其放电期间的指数电压衰减确定除颤的基本波形。为了降低除颤所需的能量，可以改变衰减的陡度（不同的电容）、持续时间（固定持续时间波形）或倾斜（固定倾斜波形）或初始极性。此外，电极的极性可以在电容器放电期间反转一次（双相波形）或两次（三相波形）。如果有两个电容器和除颤路径可用，则可以顺序地输送双向除颤脉冲。在人体中，与心内膜电极导线一起使用的原始标准波形是使用心内膜右心室电极作为阴极，由125 μF电容器输送的单相脉冲。现在已知的是，初始极性的反转和电容器放电期间的极性反转可以显著降低除颤所需的能量，从而防止以前使用内电极导线系统的除颤的频繁故障。连续脉冲的使用没有显示出能量需求的降低或仅显示出能量需求的略微降低，并且由于需要额外的电极而被放弃。使用较小的电容（60-90 μF）降低了最大能量输出，但通常不会降低除颤的能量要求。然而，对于更有效的电极，可以使用将有助于减小除颤器的尺寸的更小的电容。因此，如果使用约90-μF电容器通过双极导线系统（使用右心室电极作为阳极）输送双相脉冲，则目前除颤在能量、电容器尺寸和植入难易性方面都得到了优化。
Defibrillation of the heart is achieved if an electrical current depolarizes the majority of the unsynchronized fibrillating myocardial cells. The applied current or the corresponding voltage described as a function of time is called the waveform. In pacing, to stimulate myocardial cells close to the electrode, a relatively low voltage is needed for a relatively brief duration. However, in defibrillation, approximately a 100‐fold higher voltage is needed and achieved by the use of capacitors. The exponential voltage decay of a capacitor during its discharge determines the basic waveform for defibrillation. In an attempt to lower the energy needed for defibrillation, the steepness of the decay (different capacitances), the duration (fixed duration waveforms) or tilt (fixed tilt waveforms), or the initial polarity can be changed. Additionally, the polarity of the electrodes can be reversed during the discharge of the capacitor once (biphasic waveform) or twice (triphasic waveform). If two capacitors and defibrillation pathways are available, bidirectional defibrillation pulses can be delivered sequentially. In humans, the original standard waveform used with endocardial leads was a single monophasic pulse delivered by a 125‐μF capacitor using the endocardial right ventricular electrode as cathode. It is now known that a reversal of the initial polarity and a reversal of polarity during capacitor discharge may significantly lower the energy needed for defibrillation, thereby preventing formerly frequent failures of defibrillation with endocardial lead systems. The use of sequential pulses showed no or only slight reductions of energy requirements and was abandoned due to the additional electrode needed. The use of a smaller capacitance (60–90 μF) reduced maximum energy output but generally did not reduce energy requirements for defibrillation. However, with more efficient electrodes, smaller capacitances that will help to reduce the size of the defibrillator might be used. Thus, today defibrillation is optimized with respect to energy, capacitor size, and ease of implantation if an approximately 90‐μF capacitor is used to deliver a biphasic pulse via a bipolar lead system using the right ventricular electrode as anode.
登录
查看更多内容
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
影响因子：
37.8
作者：
DIXON, EG;TANG, ASL;IDEKER, RE
通讯作者：
IDEKER, RE
使用双相波形进行心室除颤：相持续时间的重要性。
影响因子：
24
作者：
Tang,AS;Yabe,S;Wharton,JM;Dolker,M;Smith,WM;Ideker,RE
通讯作者：
Ideker,RE
影响因子：
20.1
作者：
S. Yabe;William M. Smith;J. Daubert;P. Wolf;D. Rollins;R. Ideker
通讯作者：
S. Yabe;William M. Smith;J. Daubert;P. Wolf;D. Rollins;R. Ideker
影响因子：
20.1
作者：
Xiaohong Zhou;James P. Daubert;Patrick D. Wolf;William M. Smith;R. Ideker
通讯作者：
Xiaohong Zhou;James P. Daubert;Patrick D. Wolf;William M. Smith;R. Ideker