A Patchwork Inverse Method in Combination with the Activation Time Gradient to Detect Regions of Slow Conduction in Sinus Rhythm

Abstract

Noninvasive electrocardiographic imaging (ECGI) methods are known to produce artificial lines of block in healthy tissue. However, it remains unclear if ECGI can detect regions of slow conduction in damaged hearts. The aim of this study was to develop and test a method to detect the presence of slow conduction zones using ECGI. Activation times were estimated from simulated electrocardiograms using two classical ECGI methods and a new method called the Patchwork Method (PM), which locally selects the optimal ECGI method. Five different methods (maximum, minimum, mean, nearest neighbor and random) to compute activation time gradients were then tested to pinpoint the slow conduction zones. Overall, the local maximum and mean gradients both accurately located the zones of tissue damage. While the classical ECGI methods did not identify any of these regions, the Patchwork Method succeeded in identifying 5 of the 6 slow conduction zones. This novel approach thus overcomes some of the limitations of classic ECGI methods to detect regions of slow conduction.