Jones D L, Klein G J, Kallok M J
Am J Cardiol. 1985 Mar 1;55(6):821-5. doi: 10.1016/0002-9149(85)90163-8.
Internal cardiac defibrillation with an intravascular catheter was compared with a new method for internal cardiac defibrillation using 2 pulses delivered in sequence directly to the myocardium. For the sequential pulses, the first pulse was passed through an intravascular catheter (Medtronic 6880), between the anode in the superior vena cava-atrial junction region and the cathode in the apex of the right ventricle. The second pulse was delivered between the catheter tip in the right ventricular apex as cathode and an oval plaque electrode (Medtronic TX-7) secured on the epicardium of the left ventricular free wall as anode. Defibrillation pulses were of truncated, trapezoidal waveform (65% tilt), separated by 1, 10 and 100 ms. Using the catheter alone, 36 normal pig hearts could be defibrillated by 44 J. However, 22 pig hearts (60%) could not be defibrillated with energies below 35 J. Defibrillation threshold was improved with sequential twin pulses, the improvement being dependent on pulse separation (42, 34 and 19 J, at 100-, 10- and 1-ms separation, respectively; F = 14.6, df = 2.29, p less than 0.01). In conclusion, sequential twin pulse defibrillation provides a considerable reduction in energy necessary for defibrillation in comparison to single pulses using the catheter alone. In this study, the optimal separation was 1 ms.
将血管内导管进行的心内除颤与一种新的心内除颤方法进行了比较，后者使用依次直接施加于心肌的双脉冲。对于双脉冲，第一个脉冲通过血管内导管（美敦力6880），在腔静脉-心房交界区域的阳极与右心室心尖的阴极之间传递。第二个脉冲在右心室心尖的导管尖端作为阴极与固定在左心室游离壁心外膜上的椭圆形斑块电极（美敦力TX-7）作为阳极之间传递。除颤脉冲为截断的梯形波形（65%倾斜度），间隔分别为1、10和100毫秒。仅使用导管时，36个正常猪心脏可被44焦耳除颤。然而，22个猪心脏（60%）在能量低于35焦耳时无法除颤。双脉冲顺序除颤可改善除颤阈值，改善程度取决于脉冲间隔（间隔为100、10和1毫秒时，分别为42、34和19焦耳；F = 14.6，自由度 = 2.29，p小于0.01）。总之，与仅使用导管的单脉冲相比，双脉冲顺序除颤可显著降低除颤所需的能量。在本研究中，最佳间隔为1毫秒。
