Stajduhar K C, Ott G Y, Kron J, McAnulty J H, Oliver R P, Reynolds B T, Adler S W, Halperin B D
Arrhythmia Services, Oregon Health Sciences University, Portland 97201, USA.
J Am Coll Cardiol. 1996 Jan;27(1):90-4. doi: 10.1016/0735-1097(95)00380-0.
This study was performed to determine the optimal position for the proximal electrode in a two-electrode transvenous defibrillation system.
Minimizing the energy required to defibrillate the heart has several potential advantages. Despite the increased use of two-electrode transvenous defibrillation systems, the optimal position for the proximal electrode has not been systematically evaluated.
Defibrillation thresholds were determined twice in random sequence in 16 patients undergoing implantation of a two-lead transvenous defibrillation system; once with the proximal electrode at the right atrial-superior vena cava junction (superior vena cava position) and once with the proximal electrode in the left subclavian-innominate vein (innominate vein position).
The mean (+/- SD) defibrillation threshold with the proximal electrode in the innominate vein position was significantly lower than with the electrode in the superior vena cava position (13.4 +/- 5.7 J vs. 16.3 +/- 6.6 J, p = 0.04). Defibrillation threshold with the proximal electrode in the innominate vein position was lower or equal to that achieved in the superior vena cava position in 75% of patients. In patients with normal heart size (cardiothoracic ratio < or = 0.55), the improvement in defibrillation threshold with the proximal electrode in the innominate vein position was more significant than in patients with an enlarged heart (innominate vein 13.0 +/- 6.5 J vs. superior vena cava 17.9 +/- 5.1 J, p < 0.01). In patients with an enlarged heart, no difference between the two sites was observed (innominate vein 13.9 +/- 4.5 J vs. superior vena cava 13.6 +/- 8.3 J, p = NS).
During implantation of a two-lead transvenous defibrillation system, positioning the proximal defibrillation electrode in the subclavian-innominate vein will lower defibrillation energy requirements in the majority of patients.
本研究旨在确定双电极经静脉除颤系统中近端电极的最佳位置。
将心脏除颤所需能量降至最低有诸多潜在益处。尽管双电极经静脉除颤系统的使用日益增多，但近端电极的最佳位置尚未得到系统评估。
对16例接受双导联经静脉除颤系统植入的患者，随机顺序测定两次除颤阈值；一次将近端电极置于右心房 - 上腔静脉交界处（上腔静脉位置），另一次将近端电极置于左锁骨下 - 无名静脉（无名静脉位置）。
近端电极位于无名静脉位置时的平均（±标准差）除颤阈值显著低于位于上腔静脉位置时（13.4±5.7 J对16.3±6.6 J，p = 0.04）。75%的患者中，近端电极位于无名静脉位置时的除颤阈值低于或等于位于上腔静脉位置时的阈值。在心脏大小正常（心胸比率≤0.55）的患者中，近端电极位于无名静脉位置时除颤阈值的改善比心脏扩大的患者更显著（无名静脉13.0±6.5 J对上腔静脉17.9±5.1 J，p < 0.01）。在心脏扩大的患者中，两个部位之间未观察到差异（无名静脉13.9±4.5 J对上腔静脉13.6±8.3 J，p =无显著差异）。
在植入双导联经静脉除颤系统时，将近端除颤电极置于锁骨下 - 无名静脉可降低大多数患者的除颤能量需求。
