Electroanatomic Voltage mapping and Conduction Heterogeneity
Left and right atrial geometries created using Ensite Precision were
exported and fused with the AcQMap anatomies using fiducial points and a
nearest neighbour approach to assign bipolar voltage amplitude to each
site on the AcQMap chamber enabling comparison between sites according
to identified activation patterns.
Activation time maps obtained using Supermap were exported and analysed
offline. The local activation time difference (LAT) for a 5mm radius
from every vertex of the anatomy was calculated for each map and the
largest value taken for each point to generate a histogram. The median
LAT difference (MAT) and the conduction heterogeneity index (CHI)
(95th percentile - 5thpercentile/median) was calculated within regions shown to demonstrate
stable high frequency activation patterns during AF as described
previously(8) and the effect of extrastimulus pacing on the CHI
calculated in these regions compared to the remainder of the chamber.