Altered brain functional connectivity in paroxysmal atrial fibrillation: Insights from resting-state fMRI

Paroxysmal atrial fibrillation (PAF), an episodic form of irregular heart rhythm, is associated with changes in brain connectivity, particularly in regions involved in auto-nomic regulation. This study aimed to examine whole-brain functional connectivity (FC) in PAF patients compared to healthy controls (HCs) using resting-state functional MRI (rs-fMRI). Twenty PAF patients and 19 age and gender matched HCs underwent rs-fMRI scans. The whole-brain voxel-wise FC analysis was conducted based on regions of interest defined by the Automated Anatomical Labeling 3 (AAL3) atlas. Seed regions showing significant group differences were refined into subregions to further define the altered function network. PAF patients exhibited altered FC in several brain regions, including the left posterior orbitofrontal cortex, the left hippocampus, multiple hypothalamic nuclei, left insula, left inferior frontal gyrus opercular part, left fusiform, right globus pallidus and left ventral tegmental area. Moreover, altered FC was observed in the left ventral anterior insula and the left anterior hippocampus with enhanced connectivity in limbic regions linked to autonomic dysregulation. These findings reveal that PAF is associated with significant alterations in the neural networks that regulate emotional processing, sensory integration, and autonomic control.