Co-Author(s):
Amir Naqvi, DO
Evan Hiner, MD
Dipak Shah, MD
Ascension Providence Hospital/MSU-CHM
16001 W. 9 Mile Road 4th Flr Fisher Building Southfield, MI 48075
Introduction | Objectives: Atrial fibrillation (AF) ablation, while generally safe, can result in esophageal injury.  Esophageal temperature monitoring is routinely used to guide radiofrequency ablation (RFA).  High power short duration (HPSD) RFA is becoming more utilized.  Traditional RFA relies on distal conductive heating while HPSD creates lesions by local conductive and resistive heating; thereby, potentially minimizing esophageal injury. The objective of this study is to compare traditional versus HPSD RFA on esophageal temperature during AF ablation.
Methods: We conducted a retrospective analysis of all consecutive AF ablations performed over an 18-month period. All ablations were performed by one operator who changed his practice from traditional to HPSD RFA. The parameters of the traditional ablation were 15-30 grams of contact force, force time integral (FTI) of 400-600, and power of 20–30 Watts. The parameters for HPSD were contact force of 5-20 grams with 50 Watts of power applied for 3-15 seconds targeting a 10Ω impedance drop.  Data analysis included type of method used, temperature changes and basic characteristics including underlying type of AF. Patients were excluded if they had prior left atrial ablation.  A simple t-test analysis was done comparing both the max temperatures, as well as the absolute temperature change for each group.
Results: A total of 145 patients were included in the analysis.  72 patients in the traditional ablation group had a mean max temperature of 37.6 + 1.39 ˚C.  Comparatively, the 73 patients in the HPSD group had a mean max temperature of 37.3 + 0.646 ˚C, which was trending towards, but did not achieve statistical significance (p=0.099).  However, when comparing the absolute temperature change, HPSD RFA demonstrated a significantly less increase in temperature than the traditional RFA (1.14 + 0.48 ˚C  vs. 1.69 + 0.60 ˚C  (p< 0.0001)).
Conclusions: HPSD RFA resulted in a significantly lower esophageal temperature change likely due to less distal conductive heating.  Studies suggest numerically less atrioesophageal fistula (AEF) with HPSD, albeit it the numbers are small.  With an increasing prevalence of HPSD RFA being used significantly less AEF may be seen in AF ablation registries.