Gradaus R, Böcker D, Dorszewski A, Lamp B, Hammel D, Breithardt G, Block M
Westfälische Wilhelms-University Münster, Department of Cardiology & Angiology and Institute for Arteriosclerosis Research, Germany.
Europace. 2000 Apr;2(2):154-9. doi: 10.1053/eupc.1999.0084.
In patients with implantable cardioverter-defibrillators (ICD), the goals of lowering the defibrillation threshold (DFT) can be achieved by means of higher defibrillation safety margins, more rapid charging of capacitors, improved battery longevity, implying smaller devices. Whether an increase in the electrically active surface of ICD leads by fractal coating results in decreased DFTs is unknown.
In this prospective randomized cross-over study the defibrillation efficacy of a novel right ventricular endocardial defibrillation electrode fractally coated with iridium was compared with an uncoated but otherwise identical electrode in 30 patients undergoing ICD implantation. In each patient, DFT testing was performed twice according to a binary search protocol introducing the two different electrodes in a random order. The mean DFT was 8.4 +/- 4.1 J with the fractally coated lead and 9.6 +/- 3.6 J using the uncoated lead. The improvement of 1.2 J was statistically not significant (P = 0.11). No differences were observed between the patients with an improved DFT (n =12) and those with an unchanged or worsened DFT (n = 18) concerning age, underlying cardiac disease, NYHA class, or left ventricular ejection fraction, respectively.
Increasing the electrical surface of defibrillation leads by fractal coating does not lead to a substantial clinically relevant reduction in defibrillation thresholds. Defibrillation impedance is not influenced by the increased electrical surface of the defibrillation lead.
对于植入式心脏复律除颤器（ICD）患者，可通过提高除颤安全 margins、加快电容器充电速度、改善电池寿命（意味着设备更小）来实现降低除颤阈值（DFT）的目标。目前尚不清楚通过分形涂层增加 ICD 导线的电活性表面积是否会导致 DFT 降低。
在这项前瞻性随机交叉研究中，将 30 例接受 ICD 植入的患者中，一种新型的经铱分形涂层的右心室心内膜除颤电极的除颤效果与未涂层但其他方面相同的电极进行了比较。在每位患者中，根据二元搜索协议，以随机顺序引入两种不同的电极，进行两次 DFT 测试。分形涂层导线的平均 DFT 为 8.4±4.1 J，未涂层导线的平均 DFT 为 9.6±3.6 J。1.2 J 的改善在统计学上不显著（P = 0.11）。在 DFT 改善的患者（n = 12）和 DFT 未改变或恶化的患者（n = 18）之间，在年龄、潜在心脏病、纽约心脏协会（NYHA）分级或左心室射血分数方面均未观察到差异。
通过分形涂层增加除颤导线的电表面不会导致临床上与除颤阈值相关的实质性降低。除颤阻抗不受除颤导线电表面增加的影响。
