Esophageal electric fields are predictive of atrial cardioversion success-a finite element analysis.BACKGROUND
 Atrial fibrillation (AF) is a debilitating cardiac arrhythmia, one potential treatment of which is external cardioversion.  Studies have shown external cardioversion success is affected by electrode placement and that esophageal electric fields (EEFs) during low strength shocks have the potential to be used in determining patient-specific optimal electrode placements during animal experiments.  The objective of this study was to determine the relationship between EEFs and atrial defibrillation thresholds (ADFTs) during computer simulations using an anatomically realistic computer model of a human torso.


 Over 600 electrode placements were simulated during which EEFs were compared to ADFTs.


 There was no single optimal electrode placement with multiple electrode placements resulting in similarly low ADFTs.  There was over 40% difference in the ADFTs between the most and least optimal electrode configurations.  There was no correlation between EEFs and ADFTs for all electrode placements, but a strong negative correlation when small shifts from clinically relevant electrode placements were performed.


 CONCLUSIONS
 These results suggest a small shifts protocol from clinically relevant electrode placements has the potential to increase the probability of successful cardioversion on the first shock and reduce the cumulative number of shocks and energy to which patients are exposed.
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