| Description |
Atrial fibrillation is the most prevalent cardiac arrhythmia and causes increased risk for stroke, yet accurate pathophysiological diagnosis remains a challenge. This study aimed to further investigate the physiologic biomarkers in the left atrium (LA) related to atrial fibrillation (AF) using 4D flow data in an animal model with experimentally induced atrial fibrillation. Velocity-encoded phase contrast magnetic resonance angiography was used to gather 4D flow data in sinus rhythm and after 6 months of AF. Several metrics including mean velocity, peak velocity, stasis and vorticity were analyzed with custom created MatLab code and compared across regions of the LA including fibrotic regions determined from LGE MRI of the LA. Decrease in mean velocity, peak velocity, and increase in stasis were comparable to previous studies. Vorticity increased on average across the cardiac cycle, except in the LAA. Vorticity decreased on average at peak flow time in certain regions, but not the entirety of the LA. Vorticity and velocity were similar in fibrotic and non-fibrotic regions of the LA wall. The results support previous research indicating stasis and peak velocity as consistently relevant biomarkers, while suggesting AF also causes more rotational, stagnant blood flow patterns between contractions of the LA. Vorticity therefore has the potential to indicate prothrombotic conditions in the LA but needs further investigation with larger sample sizes. |
