ALTERATIONS OF SPONTANEOUS BRAIN ACTIVITY, SYNCHRONIZATION ACTIVITY, AND FUNCTIONAL CONNECTIVITY IN PATIENTS WITH ATRIAL FIBRILLATION: A RESTING-STATE FUNCTIONAL MAGNETIC RESONANCE IMAGING STUDY

Shuai Guo¹, Dayang Huang¹, Dechun Yin¹, Lulu Li², Xiufen Qu^{1, *}

¹Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, Harbin, China - ²Department of Radiology, The First Affiliated Hospital of Harbin Medical University, Harbin, China

Background: A large network of brain regions control cardiovascular function, with particular relevance to arrhythmogenesis. Resting-state functional magnetic resonance imaging (rs-fMRI), a non-invasive approach to localizing and measuring neural activity. 

Methods: Our study involved healthy participants as control (CON), and patients with paroxysmal atrial fibrillation (PAF). We collected the rs-fMRI data and combined different methods to identify arrhythmia-related alterations in brain function: the amplitude of low-frequency fluctuations (ALFF), fractional-amplitude of low-frequency fluctuations (fALFF), regional homogeneity (ReHo), and seed-based functional connectivity (FC). 

Results: Compared with the CON group, the PAF group showed decreased ALFF in the left inferior temporal gyrus, and increased fALFF mainly in the right middle occipital gyrus. The values of ReHo were mainly decreased in the left middle temporal gyrus and increased in the left middle frontal gyrus orbital part. With altered regions as seeds, disturbed functional connectivity mainly distributed in the right inferior frontal gyrus triangular part, left middle temporal gyrus, left superior temporal gyrus, left insula, and left caudate nucleus, the right superior temporal gyrus, right angular gyrus, left supramarginal gyrus, and left hippocampus. 

Conclusion: In patients with PAF, the regions with alteration of brain activity indicated that an altered parasympathetic tone may be main responsible for PAF. Our study can help to devise neuromodulation therapeutic targets for the management of arrhythmias.