A Comparison of Methods for Fiber Direction Estimation from Electrograms

The estimation of conductivity parameters from Electrograms (EGMs) could provide valuable insights into the underlying electrophysiological mechanisms of cardiac arrhythmia.However, accurate estimation requires knowledge of the fiber orientation.Despite numerous proposed methods for determining the fiber direction from EGMs' derived activation and voltage maps, the most accurate approach remains uncertain.This study presents a performance evaluation of the different estimation techniques employing data generated from four distinct monodomain cardiac models mimicking the complex fiber distribution in Bachmann's bundle, the left atrium, and the left ventricle.The findings reveal that approaches based on ellipse-fitting to the projected components of local conduction velocity or slowness vectors, computed from an activation map, offer the highest accuracy.Nevertheless, the methods are susceptible to fiber direction heterogeneity across the myocardial wall.