电极长度对心房除颤阈值的影响。

Timmermans C, Rodriguez L M, Ayers G M, Lambert H, Smeets J, Wellens H J

Department of Cardiology, Academic Hospital Maastricht, The Netherlands.

J Cardiovasc Electrophysiol. 1998 Jun;9(6):582-7. doi: 10.1111/j.1540-8167.1998.tb00938.x.

INTRODUCTION

Catheter-based electrodes have been used previously to terminate episodes of atrial fibrillation in animals and man. Typically, these electrodes span 6 to 7 cm, and lowest energy requirements are achieved when these electrodes are positioned in the distal coronary sinus and in the right atrium. The purpose of this study was to evaluate the use of longer electrode lengths for atrial defibrillation.

METHODS AND RESULTS

In 15 patients, two decapolar catheters were inserted, one into the distal coronary sinus and one in the right atrium. To provide longer electrodes lengths, a third catheter was inserted and alternated positioned in the right atrium or coronary sinus. A 6-cm electrode span was obtained by using the distal 8 rings on the coronary sinus catheter or 8 consecutive electrodes on the right atrial catheter and increased from 6 to 11 cm by connecting 5 consecutive, nonoverlapping rings of the third catheter with the 10 rings of the initial right atrial or coronary sinus catheter. Atrial defibrillation thresholds were determined twice, in a randomized order, in each patient for each of the three combinations of electrode lengths. All 15 patients could be successfully converted to sinus rhythm without complications; however, one patient could be converted reproducibly with only 2 of the 3 electrode combinations. Mean thresholds were 306 +/- 102 V, 5.9 +/- 4.0 J for the 6 cm/6 cm electrode length combination with an impedance of 72 +/- 18 omega. For the electrode combination using the 11-cm electrode in the right atrium, the defibrillation threshold was 296 +/- 107 V, 5.8 +/- 3.9 J with an impedance of 61 +/- 17 omega and was 294 +/- 91 V, 5.6 +/- 3.6 J with an impedance of 55 +/- 11 omega for the 11-cm electrode in the coronary sinus. There were no significant differences in defibrillation voltage or energy (P > 0.05) associated with the longer electrode lengths; however, the longer electrode lengths did significantly lower shock impedance (P < 0.05).

CONCLUSION

The use of longer electrodes, when using the right atrium to coronary sinus shock vector, does not lower the defibrillation requirements for restoration of sinus rhythm.

引言

基于导管的电极此前已用于终止动物和人类的房颤发作。通常，这些电极跨度为6至7厘米，当这些电极置于冠状静脉窦远端和右心房时，能量需求最低。本研究的目的是评估使用更长电极长度进行心房除颤的效果。

方法与结果

在15例患者中，插入两根十极导管，一根置于冠状静脉窦远端，一根置于右心房。为了提供更长的电极长度，插入第三根导管，并交替置于右心房或冠状静脉窦。通过使用冠状静脉窦导管上的远端8个环或右心房导管上的8个连续电极获得6厘米的电极跨度，并通过将第三根导管的5个连续、不重叠的环与初始右心房或冠状静脉窦导管的10个环相连，将电极跨度从6厘米增加到11厘米。对每位患者的三种电极长度组合，以随机顺序测定两次心房除颤阈值。所有15例患者均能成功转为窦性心律，无并发症；然而，只有1例患者能用3种电极组合中的2种重复转为窦性心律。对于6厘米/6厘米电极长度组合，平均阈值为306±102伏，5.9±4.0焦，阻抗为72±18欧姆。对于在右心房使用11厘米电极的电极组合，除颤阈值为296±107伏，5.8±3.9焦，阻抗为61±17欧姆；对于在冠状静脉窦使用11厘米电极的情况，除颤阈值为294±91伏，5.6±3.6焦，阻抗为55±11欧姆。较长电极长度相关的除颤电压或能量无显著差异（P>0.05）；然而，较长电极长度确实显著降低了电击阻抗（P<0.05）。