Cardiac remodeling as a consequence of atrial fibrillation: An anatomical study of perfusion-fixed human heart specimens

Background: Atrial fibrillation (AF) causes a continuum of atrial anatomical remodeling. Methods: Using a library of perfusion-fixed human hearts, specimens with AF were compared to controls. During this preliminary assessment study, direct measurements were taken of atrial volume, pulmonary vein (PV) circumference, and left atrial (LA) wall thicknesses. Results: Hearts with AF typically had larger atrial volumes, as well as a much larger variation in volume compared to controls (range of 59.6-227.1 mL in AF hearts compared to 65.1-115.9 mL in controls). For all hearts, right PVs were larger than left PVs (mean: 171.4 ± 84.6 mm² for right and 118.2 ± 50.1 mm²for left, P < 0.005). LA wall thicknesses ranged from 0.7 mm to 3.1 mm for both AF and control hearts. Conclusions: Hearts with AF had a large range of sizes which is consistent with the progression of atrial remodeling during AF. The large range of thicknesses will influence the amount of energy needed to create transmural lesions during ablation procedures.