Obesity and Atrial Fibrillation: A Chronic Ovine Study

Abstract

Obesity is associated with atrial fibrillation. Mechanisms resulting in a proarrhythmic substrate remain unknown. Methods: Thirty sheep commenced on a high caloric energy-dense diet, along with 6 weight-maintenance controls were samples at baseline, 4 and 8 months for cardiac MRI, invasive hemodynamic measures (LA and systemic pressure) and detaild electrophysiologic studies. A custom-made 128-electrode plaque applied to the LA and RA was used to quantify effective refractory periods (ERP), conduction velocity (CV) and conduction hererogeneity index (CHI) at 4 pacing cycle lengths (CL) from 4 sites. AF indicibility by ramp pacing was recorded. Quantitative histology was performed for fibrosi..