Related Experiment Video
Updated: Jan 10, 2026
Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation
Published on: July 20, 2022
Left Atrial Wall Thickness as a Marker of Atrial Substrate in Patients With Atrial Fibrillation
Michael W Lim1, Geoffrey R Wong2, Troy W Watts3
1Royal Melbourne Hospital, Melbourne, Victoria, Australia; Alfred Hospital, Melbourne, Victoria, Australia; University of Melbourne, Melbourne, Victoria, Australia; Baker Heart and Diabetes Research Institute, Melbourne, Victoria, Australia.
Background:
Atrial substrate is characterized by regions of reduced bipolar voltage (BV), conduction velocity slowing, and complex potentials. It is thought to reflect the myocardial tissue loss and interstitial fibrosis that typifies atrial remodeling. Whether this remodeling results in regional changes in left atrial wall thickness (LAWT) is unclear.
Objectives:
This study sought to determine whether computed tomography (CT)-derived LAWT is associated with regional atrial substrate in atrial fibrillation (AF) patients.
Methods:
High-density electroanatomic maps of the left atrium (LA) were created in a cohort of adult patients undergoing index AF ablation. LAWT derived from the preprocedure CT utilizing automated postprocessing software was correlated with electrical markers of atrial substrate in the overall LA and at 6 predefined atrial regions.
Results:
The study included 77 patients. In multiple linear regression analyses incorporating mean LAWT, age, body mass index, AF type, and LA volume, mean LAWT was an independent predictor of mean BV (β = 1.34; P < 0.001) and conduction velocity (β = 25.63; P = 0.005) as well as an independent predictor of the percentage of low voltage (β = -30.80; P < 0.001) and conduction slowing/block (β = -31.69; P = 0.013) points. Regional mean LAWT was an independent predictor of regional mean BV across all 6 predefined LA segments (anterior/posterior/roof/inferior/septal/lateral). Regional mean LAWT of the anterior (β = -5.42; P = 0.033) and roof (β = -3.17; P = 0.021) segments were also independent predictors of the percentage of complex potentials in the corresponding segments.
Conclusions:
CT-derived LAWT is a promising noninvasive marker of LA substrate.
