Within-subject alterations in CSF and blood flow dynamics following rhythm-control intervention in atrial...

Cardiac- and respiration-driven vascular pulsations influence cerebrospinal fluid (CSF) oscillations and neurofluid dynamics and are considered relevant for perivascular fluid transport and brain homeostasis. In atrial fibrillation (AF), irregular cardiac rhythm alters cerebral hemodynamics and may affect CSF flow dynamics. This exploratory pre-post pilot study investigated physiological changes in CSF and blood flow dynamics following AF intervention.

This pilot study included 7 patients with AF, using a 3 T MRI system. To capture CSF and blood flow, real-time phase-contrast flow MRI was employed in the aqueduct, the internal carotid artery, the jugular vein and the sagittal sinus. T1-weighted MRI and fast T1 mapping characterized the tissue anatomy and integrity and EPI diffusion assessed fluid motion along the perivascular space. Artefact-free STEAM diffusion described whole-brain CSF dynamics. Physiological data were recorded simultaneously during MRI.

Before intervention, AF patients exhibited reduced CSF flow and irregular CSF oscillatory patterns. After intervention, CSF dynamics shifted toward more periodic, cardiac-dominated oscillatory patterns, with increased CSF flow volume, consistent with altered neurofluid dynamics following restoration of sinus rhythm. Blood flow in the internal carotid artery, jugular vein, and sagittal sinus similarly shifted toward sinus rhythmic patterns, while DTI-ALPS, quantitative T1 measures, brain volume, ventricular size, and white matter integrity remained unchanged.

Within-subject comparisons indicated that restoration of sinus rhythm was accompanied by measurable alterations in CSF and blood flow dynamics.