Mischke Karl, Schimpf Thomas, Knackstedt Christian, Eickholt Christian, Hanrath Peter, Kelm Malte, Schauerte Patrick
Department of Cardiology, RWTH Aachen University, 52074 Aachen, Germany.
Am J Emerg Med. 2008 Mar;26(3):287-90. doi: 10.1016/j.ajem.2007.05.017.
Increasing duration of ventricular fibrillation (VF) is associated with a higher risk of ineffective resuscitation. In addition, precountershock chest compression can influence defibrillation success. Transesophageal defibrillation may increase defibrillation success because of the proximity of the esophagus to the heart. We evaluated the efficacy of transesophageal defibrillation compared with standard transthoracic defibrillation after long episodes of VF.
Defibrillation success after 10 minutes of untreated VF was evaluated in 12 sheep randomized into 2 groups: (group A) in 6 sheep, up to 3 transthoracic shocks were applied, followed by up to 3 transesophageal shocks (first shock: 150 J, second and third shocks: 200 J). (group B) In 6 sheep, 2 minutes of precountershock chest compression preceded the defibrillation shocks. Truncated biphasic shocks were delivered between a sternal and an apical patch electrode for transthoracic defibrillation and between an esophageal and a cutaneous patch electrode for transesophageal defibrillation.
In group A with no precountershock chest compression, external defibrillation failed despite shocks with maximum energy (200 J) in all 6 sheep. Transesophageal defibrillation was successful in 3 sheep (50%). In group B with precountershock chest compression, external defibrillation failed in all 6 sheep. Transesophageal defibrillation was successful with the first shock in all 6 sheep.
Transesophageal defibrillation may terminate VF of long duration that is refractory to standard defibrillation. Precountershock chest compression may increase transesophageal defibrillation success.
心室颤动（VF）持续时间的增加与复苏无效风险的升高相关。此外，电击前胸部按压会影响除颤成功率。由于食管与心脏距离较近，经食管除颤可能会提高除颤成功率。我们评估了在长时间VF发作后，经食管除颤与标准经胸除颤相比的疗效。
将12只绵羊随机分为2组，评估未经治疗的VF持续10分钟后的除颤成功率：（A组）6只绵羊，先进行多达3次经胸电击，随后进行多达3次经食管电击（第一次电击：150 J，第二次和第三次电击：200 J）。（B组）6只绵羊，在除颤电击前先进行2分钟电击前胸部按压。经胸除颤在胸骨和心尖贴片电极之间施加截断双相电击，经食管除颤在食管和皮肤贴片电极之间施加。
在没有电击前胸部按压的A组中，所有6只绵羊尽管使用了最大能量（200 J）电击，体外除颤仍失败。经食管除颤在3只绵羊中成功（50%）。在有电击前胸部按压的B组中，所有6只绵羊的体外除颤均失败。经食管除颤在所有6只绵羊中首次电击即成功。
经食管除颤可能终止对标准除颤难治的长时间VF。电击前胸部按压可能会提高经食管除颤成功率。
