Chapman P D, Vetter J W, Souza J J, Troup P J, Wetherbee J N, Hoffmann R G
Medical College of Wisconsin, Department of Medicine 53226.
J Am Coll Cardiol. 1988 Sep;12(3):739-45. doi: 10.1016/0735-1097(88)90315-4.
Pentobarbital-anesthetized dogs were studied to determine the relative efficacy of monophasic and biphasic truncated exponential shocks employing a nonthoracotomy internal defibrillation pathway that consisted of a right ventricular catheter electrode (cathode) and a subcutaneous chest wall patch electrode (anode). In part 1 of the experiments, six dogs (19.6 +/- 1.1 kg) were utilized. Monophasic pulses of 5, 7.5, 10 and 12.5 ms duration were compared with biphasic pulses of the same total duration. The biphasic pulses had an initial positive phase (P1) followed by a terminal negative phase (P2) with the initial voltage equal for each phase. For each biphasic total pulse width, five relative P1 versus P2 durations were tested (50 and 50%, 75 and 25%, 90 and 10%, 25 and 75%, 10 and 90%). Ventricular fibrillation was induced by alternating current and pulse configurations were tested randomly to determine the minimal voltage and energy for defibrillation (threshold). Biphasic shocks with P1 longer than P2 were associated with significantly lower (p less than 0.01) energy thresholds than were monophasic shocks. Additionally, there was no significant relation between pulse width and voltage or energy thresholds. In part 2 of the experiments, six dogs (20.2 +/- 1.6 kg) were studied. Monophasic shocks were compared with biphasic shocks with P1 versus P2 durations of 75 and 25% and 90 and 10% for total pulse widths of 7.5, 10 and 12.5 ms. Threshold determinations were performed as in part 1. Subsequently, five initial voltages clustered about threshold were randomly tested four times and dose-response curves constructed for each pulse configuration with the use of stepwise logistic regression. Biphasic shocks resulted in significantly lower energy (p less than 0.0001) and voltage (p less than 0.001) requirements than did monophasic shocks.(ABSTRACT TRUNCATED AT 250 WORDS)
对戊巴比妥麻醉的犬进行研究，以确定采用非开胸体内除颤途径（由右心室导管电极（阴极）和胸壁皮下贴片电极（阳极）组成）的单相和双相截断指数电击的相对疗效。在实验的第1部分，使用了6只犬（19.6±1.1千克）。将持续时间为5、7.5、10和12.5毫秒的单相脉冲与相同总持续时间的双相脉冲进行比较。双相脉冲有一个初始正相（P1），随后是一个终末负相（P2），每个相的初始电压相等。对于每个双相总脉冲宽度，测试了五个相对的P1与P2持续时间（50%和50%、75%和25%、90%和10%、25%和75%、10%和90%）。通过交流电诱发心室颤动，并随机测试脉冲配置，以确定除颤的最小电压和能量（阈值）。P1长于P2的双相电击的能量阈值显著低于单相电击（p<0.01）。此外，脉冲宽度与电压或能量阈值之间没有显著关系。在实验的第2部分，研究了6只犬（20.2±1.6千克）。将单相电击与双相电击进行比较，双相电击的P1与P2持续时间分别为75%和25%以及90%和10%，总脉冲宽度为7.5、10和12.5毫秒。阈值测定与第1部分相同。随后，对围绕阈值聚类的五个初始电压进行四次随机测试，并使用逐步逻辑回归为每个脉冲配置构建剂量反应曲线。双相电击所需的能量（p<0.0001）和电压（p<0.001）显著低于单相电击。（摘要截断于250字）
