Related Experiment Video
Updated: Sep 2, 2025
Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation
Published on: July 20, 2022
Stroke risk evaluation for patients with atrial fibrillation: Insights from left atrial appendage with
Runxin Fang1, Zidun Wang2, Xie Zhao3
1School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China.
Insights
Patients with non-valvular atrial fibrillation (NVAF) and stroke history have distinct left atrial appendage (LAA) characteristics. These anatomical and blood flow differences, including lower LAA velocities and higher particle residual rates, may help predict stroke risk.
Area of Science:
- Cardiology
- Medical Imaging
- Biomedical Engineering
Background:
- Cardioembolic strokes in non-valvular atrial fibrillation (NVAF) often originate from the left atrial appendage (LAA).
- Current stroke risk assessment relies on general clinical factors, not individual LAA anatomy or hemodynamics.
Purpose of the Study:
- To investigate differences in LAA morphology and hemodynamics between NVAF patients with and without a history of stroke.
- To identify specific LAA parameters that could improve stroke risk stratification.
Main Methods:
- Reconstructed 3D geometric models of the LAA from 39 NVAF patients (17 non-stroke, 22 stroke history).
- Measured morphological parameters (tortuosity, orifice area) and hemodynamic parameters (orifice velocities) using fluid-structure interaction analysis.
- Analyzed particle residual rates (PRR) and blood renewal rates (BRR) to assess thrombogenesis dynamics.
Main Results:
- The stroke group exhibited significantly lower LAA tortuosity and orifice area compared to the non-stroke group.
- Significantly lower LAA orifice velocities were observed in the stroke group (0.15 ± 0.06 cm/s vs 0.16 ± 0.10 cm/s).
- The stroke group showed significantly higher PRR (14.58 ± 9.43 vs 9.25 ± 4.67) and BRR (52.41 ± 18.11 vs 38.36 ± 24.07).
Conclusions:
- Specific LAA morphological and hemodynamic parameters differ significantly between NVAF patients with and without stroke history.
- These parameters, including LAA shape, flow dynamics, and thrombogenesis indicators, show potential for enhanced individual stroke risk assessment in NVAF patients.
Abstract:
The majority of cardioembolic strokes in patients with non-valvular atrial fibrillation (NVAF) are resulted from clot formation in the left atrial appendage (LAA). Current stroke risk stratification is based on the overall risks estimated from demographic and clinical profiles but not on individual anatomy or physiology. We aim to explore the differences in LAA morphological and hemodynamic parameters by comparing patients with and without a stroke history. Thirty-nine patients with persistent NVAF were included. Of these, 17 patients without a stroke history (non-stroke group) were compared with 22 patients with a history of stroke (stroke group). Their LAA geometric models were first reconstructed, and the morphological parameters were then measured. Furthermore, their LAA hemodynamic parameters were calculated by fluid-structure interaction analysis. Moreover, particle residual rates (PRR) and blood renewal rates (BRR) analyses were also employed to characterize the thrombogenesis dynamics. The results showed that compared to the non-stroke group, the stroke group had significant smaller LAA tortuosity and LAA orifice area, and significantly lower LAA orifice velocities (0.16 ± 0.10 vs 0.15 ± 0.06 cm/s; p = 0.044), but higher PRR (14.58 ± 9.43 vs 9.25 ± 4.67; p = 0.040) and BRR (52.41 ± 18.11 vs 38.36 ± 24.07; p = 0.044). These LAA morphological and hemodynamic parameters may be used to assess stroke risk in patients with NVAF.
