Abstract 17049: Computer Simulation to Study the Effect of Structural Remodeling on Atrial Fibrillation Using Clinically-obtained Cardiac MRIs
Introduction: Structural remodeling of the atria in the form of fibrosis is known to be a contributing factor for the initiation and maintenance of atrial fibrillation (AF).
Hypothesis: Using computer simulation based on clinically-obtained MRIs, we tested the hypothesis that both dense and diffuse fibrosis play significant roles in the inducibility of AF and the effectiveness of pulmonary vein (PV) ablation.
Methods: Magnetic resonance angiograms and delayed enhancement MRIs (DEMRIs) of the left atrium from 34 AF patients were used to construct the models for the computer simulations. Using the Fenton-Karma action potential model, three conditions were tested for AF inducibility: 1) no fibrosis, 2) diffuse fibrosis, and 3) diffuse and dense fibrosis. AF induction was attempted at each of the four PVs and episodes lasting >30 s were considered sustained. Wide area PV ablation was simulated on all sustained episodes.
Results: With no fibrosis, sustained AF was achieved in 55.9±32.0% of induction attempts. This percentage was significantly increased to 92.6±15.7% and 93.4±12.8% with diffuse fibrosis and combined dense and diffuse fibrosis, respectively (p<0.0001 for both). PV ablation terminated 75% of episodes induced with no fibrosis, 62% with diffuse fibrosis and 60% with combined dense and diffuse fibrosis. Organized reentry usually formed after ablation with dense scar providing an anchor for reentry in episodes where dense scar is present.
Conclusions: Both diffuse and dense fibrosis significantly increases the likelihood for AF induction and maintenance in the computer model with dense fibrosis providing additional anchor points in the left atrium for reentrant circuits.
Author Disclosures: J. Ng: Research Grant; Significant; NIH. J.K. Ng: Research Grant; Significant; NIH. P. Parikh: Research Grant; Significant; AHA. J.J. Goldberger: Research Grant; Significant; NIH. M. Markl: Research Grant; Significant; NIH. J. Carr: Research Grant; Significant; NIH. W. Bai: None. P. Kanagaratnam: None. P.B. Lim: None. L.C. Malcolme-Lawes: None. N.A. Qureshi: None. N.S. Peters: None.
- © 2015 by American Heart Association, Inc.