Validating Left Atrial Low Voltage Areas During Atrial Fibrillation and Atrial Flutter Using Multielectrode Automated Electroanatomic Mapping.

ABSTRACT

OBJECTIVES: This study aimed 1) to determine the voltage correlation between sinus rhythm (SR) and atrial fibrillation (AF)/atrial flutter (AFL) using multielectrode fast automated mapping; 2) to identify a bipolar voltage cutoff for scar and/or low voltage areas (LVAs); and 3) to examine the reproducibility of voltage mapping in AF. BACKGROUND: It is unclear if bipolar voltage cutoffs should be adjusted depending on the rhythm and/or area being mapped. METHODS: High-density mapping was performed first in SR and afterward in induced AF/AFL. In some patients, 2 maps were performed during AF. Maps were combined to create a new one. Points of <1 mm difference were analyzed. Correlation was explored with scatterplots and agreement analysis was assessed with Bland-Altman plots. The generalized additive model was also applied. RESULTS: A total of 2,002 paired-points were obtained. A cutoff of 0.35 mV in AFL predicted a sinus voltage of 0.5 mV (95% confidence interval [CI] 0.12 to 2.02) and of 0.24 mV in AF (95% CI 0.11 to 2.18; specificity [SP] 0.94 and 0.96; sensitivity [SE] 0.85 and 0.75, respectively). When generalized additive models were used, a cutoff of 0.38 mV was used for AFL for predicting a minimum value of 0.5 mV in SR (95% CI 0.5 to 1.6; SP 0.94, SE 0.88) and of 0.31 mV for AF (95% CI 0.5 to 1.2; SP 0.95, SE 0.82). With regard to AF maps, there was no change in the classification of any left atrial region other than the roof. CONCLUSIONS: It is possible to establish new cutoffs for AFL and/or AF with acceptable validity in predicting a sinus voltage of <0.5 mV. Multielectrode fast automated mapping in AFL and/or AF seems to be reliable and reproducible when classifying LVAs. These observations have clinical implications for left atrial voltage distribution and in procedures in which scar distribution is used to guide pulmonary vein isolation and/or re-isolation.