Flow mechanisms driving left atrial hemodynamics under mechanical circulatory support in heart failure with preserved ejection fraction
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061907_1_5.0325596.pdf
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Published version
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1.63 MB
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3c7a7055532b9682862cd6b8487a9f5a
Author(s)
Langer, Nina
Khamooshi, Mehrdad
Singh, Manisha
Atkinson, Callum
Roche, Ellen T
Gregory, Shaun D
Date Issued
June 10, 2026
Journal
Physics of Fluids
Publisher
AIP Publishing
Citation
Nina Langer, Mehrdad Khamooshi, Manisha Singh, Callum Atkinson, Ellen T. Roche, Shaun D. Gregory; Flow mechanisms driving left atrial hemodynamics under mechanical circulatory support in heart failure with preserved ejection fraction. Physics of Fluids 1 June 2026; 38 (6): 061907.
Version
Final published version
Abstract
Mechanical circulatory support (MCS) alters cardiac flow dynamics and can contribute to thrombosis. Although commonly used for heart failure with reduced ejection fraction, its application in patients with preserved ejection fraction (HFpEF), nearly half of all heart failure cases, remains limited. Left atrial (LA) inflow cannulation may be advantageous for HFpEF patients due to their reduced ventricular volume, but the resulting LA flow disturbances are not well understood. This study evaluates how MCS affects LA blood flow dynamics in a HFpEF patient to clarify mechanisms influencing thrombosis risk. The effects of cannula length and drainage flow rate on thrombosis-related flow characteristics were quantified. To assess the importance of atrial mechanics, simulations incorporating LA contraction were compared with rigid-wall models, addressing the common simplification of rigid geometries. Predictions were validated against two-dimensional magnetic resonance imaging measurements obtained using a soft-robotic LA model. MCS increased washout by 50% under rigid-wall conditions and 27% with wall contraction compared with unassisted flow. However, thrombus risk increased with cannula advancement, driven by up to 151% higher shear stress. LA wall contraction reduced stasis by 68% and improved washout but also elevated predicted wall shear stress. Cannula advancement and its proximity to pulmonary veins and the mitral valve altered local flow structures and shear stress distributions, demonstrating the benefit of patient-specific positioning. Overall, MCS can enhance LA flow, but lower insertion depth and reduced pump flow may mitigate cannula-related thrombus risk. Even minimal atrial contraction notably affected washout, residence time, and shear stress patterns, highlighting its importance in thrombosis assessment.
MIT Department
Massachusetts Institute of Technology. Institute for Medical Engineering & Science
Massachusetts Institute of Technology. Department of Mechanical Engineering
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DOI of Published Version
https://doi.org/10.1063/5.0325596
