Obesity results in progressive atrial structural and electrical remodeling: implications for atrial fibrillation

Hany S Abed, Chrishan Surendran Samuel, Dennis H Lau, Darren James Kelly, Simon Guy Royce, Muayad Alasady, Rajiv Mahajan, Pawel Kuklik, Yuan (Michael) Zhang, Anthony G Brooks, Adam J Nelson, Stephen G Worthley, Walter Abhayaratna, Johnathon Kalman, Gary G Wittert, Prashanthan Sanders

Research output: Contribution to journalArticleResearchpeer-review

288 Citations (Scopus)


BACKGROUND: Obesity is associated with atrial fibrillation (AF); however, the mechanisms by which it induces AF are unknown. OBJECTIVE: To examine the effect of progressive weight gain on the substrate for AF. METHODS: Thirty sheep were studied at baseline, 4 months, and 8 months, following a high-calorie diet. Ten sheep were sampled at each time point for cardiac magnetic resonance imaging and hemodynamic studies. High-density multisite biatrial epicardial mapping was used to quantify effective refractory period, conduction velocity, and conduction heterogeneity index at 4 pacing cycle lengths and AF inducibility. Histology was performed for atrial fibrosis, inflammation, and intramyocardial lipidosis, and molecular analysis was performed for endothelin-A and -B receptors, endothelin-1 peptide, platelet-derived growth factor, transforming growth factor beta1, and connective tissue growth factor. RESULTS: Increasing weight was associated with increasing left atrial volume (P = .01), fibrosis (P = .02), inflammatory infiltrates (P = .01), and lipidosis (P = .02). While there was no change in the effective refractory period (P = .2), there was a decrease in conduction velocity (P
Original languageEnglish
Pages (from-to)90 - 100
Number of pages11
JournalHeart Rhythm
Issue number1
Publication statusPublished - 2013

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