Fitch David A, Soberman Judith, De Jongh Curry Amy L
Department of Biomedical Engineering, The University of Memphis, Memphis, TN, USA.
Pacing Clin Electrophysiol. 2012 Mar;35(3):335-40. doi: 10.1111/j.1540-8159.2011.03291.x. Epub 2011 Dec 21.
Atrial fibrillation (AF) is a common cardiac arrhythmia characterized by disorganized cardiac electrical activity. Defibrillation electrode placement has been shown to affect the amount of energy and number of shocks required to defibrillate. The objective of this study was to investigate the relationship between esophageal electric fields (EEFs) and atrial defibrillation thresholds (ADFTs) to determine the feasibility of using EEFs during a low-strength shock to predict patient-specific defibrillation electrode placements.
AF was induced and defibrillated according to a Bayesian four-shock protocol for 12-electrode placements in six pigs. EEFs were measured during each of the four shocks of the protocol and during a 1-J shock for each electrode placement. Squared EEFs (EEF(2) s) during all shocks were compared to the ADFTs using a linear regression.
There was a negative relationship between EEF(2) s during the 1-J shocks and ADFTs, with median R(2) values of 0.863 and 0.840 for anterior-anterior (AA) and anterior-posterior (AP) electrode placements, respectively. There was a strong, positive relationship between applied energy and EEF(2) s, with median R(2) values of at least 0.866 for all animals. The placement with the highest EEF(2) resulted in the lowest ADFT for both AA and AP placements in four of six pigs. In the other two animals, this held for one electrode set but not both.
There was a strong negative relationship between EEF(2) s during 1-J shocks and ADFTs for both AA and AP electrode placements. These preliminary results suggest that using EEF(2) s to predict patient-specific electrode placements is feasible.
心房颤动（AF）是一种常见的心律失常，其特征为心脏电活动紊乱。已表明除颤电极的放置会影响除颤所需的能量和电击次数。本研究的目的是调查食管电场（EEF）与心房除颤阈值（ADFT）之间的关系，以确定在低强度电击期间使用EEF预测患者特异性除颤电极放置的可行性。
根据贝叶斯四电击方案，在六头猪身上诱导并进行12种电极放置的除颤。在方案的四次电击期间以及每次电极放置的1焦耳电击期间测量EEF。使用线性回归将所有电击期间的EEF平方（EEF²）与ADFT进行比较。
1焦耳电击期间的EEF²与ADFT之间存在负相关，前 - 前（AA）和前 - 后（AP）电极放置的中位数R²值分别为0.863和0.840。施加能量与EEF²之间存在强正相关，所有动物的中位数R²值至少为0.866。对于六头猪中的四头，EEF²最高的放置导致AA和AP放置的ADFT最低。在另外两头动物中，这仅适用于一组电极，而非两组。
对于AA和AP电极放置，1焦耳电击期间的EEF²与ADFT之间存在强负相关。这些初步结果表明，使用EEF²预测患者特异性电极放置是可行的。
