Atrial fibrillation is associated with altered left-to-right atria gene expression ratio: implications for arrhythmogenesis and thrombogenesis

Background: Atrial fibrillation (AF) causes atrial remodeling, and the left atrium (LA) is the favored substrate for maintaining AF. However, it remains unclear if AF remodels both atria differently and contributes to LA arrhythmogenesis and thrombogenesis. Results: AF was associated with differential LA-to-RA gene expression related to specific ion channels and pathways as well as upregulation of thrombogenesis-related genes in the LA appendage. Targeting the molecular mechanisms underlying the LA-to-RA difference and AF-related remodeling in the LA appendage may help provide new therapeutic options in treating AF and preventing thromboembolism in AF. Paired left atrial and right atrial specimens were obtained from 13 patients with persistent AF receiving valvular surgery. The Paired specimens were sent for microarray comparison. Selected results were validated by quantitative real time-PCR (q-PCR) and Western blotting. Ultrastructural changes in the atria were evaluated by immunohistochemistry.