Pulmonary vein flow split effects in patient-specific simulations of left atrial flow

Eduardo Durán; Manuel García-Villalba; Pablo Martínez-Legazpi; Alejandro Gonzalo; Elliot McVeigh; Andrew M Kahn; Javier Bermejo; Oscar Flores; Juan Carlos Del Álamo

doi:10.1016/j.compbiomed.2023.107128

Pulmonary vein flow split effects in patient-specific simulations of left atrial flow

Comput Biol Med. 2023 Sep:163:107128. doi: 10.1016/j.compbiomed.2023.107128. Epub 2023 Jun 12.

Authors

Eduardo Durán¹, Manuel García-Villalba², Pablo Martínez-Legazpi³, Alejandro Gonzalo⁴, Elliot McVeigh⁵, Andrew M Kahn⁶, Javier Bermejo⁷, Oscar Flores⁸, Juan Carlos Del Álamo⁹

Affiliations

¹ Department of Mechanical, Thermal and Fluids Engineering, Universidad de Málaga, Málaga, Spain; Department of Aerospace Engineering, University Carlos III of Madrid, Leganés, Spain. Electronic address: eduran@uma.es.
² Institute of Fluid Mechanics and Heat Transfer, TU Wien, Vienna, Austria.
³ Department of Mathematical Physics and Fluids, Universidad Nacional de Educación a Distancia, Madrid, Spain.
⁴ Department of Mechanical Engineering, University of Washington, Seattle, WA, United States.
⁵ Department of Bioengineering, University of California San Diego, La Jolla, CA, United States; Department of Radiology, University of California San Diego, La Jolla, CA, United States.
⁶ Division of Cardiovascular Medicine, University of California San Diego, La Jolla, CA, United States.
⁷ Gregorio Marañón University Hospital, Madrid, Spain; Spanish Cardiovascular Network (CIBERCV), Carlos III Health Institute, Madrid, Spain; Faculty of Medicine, Complutense University, Madrid, Spain; Gregorio Marañón Health Research Institute (IISGM), Madrid, Spain.
⁸ Department of Aerospace Engineering, University Carlos III of Madrid, Leganés, Spain.
⁹ Department of Mechanical Engineering, University of Washington, Seattle, WA, United States; Center for Cardiovascular Biology, University of Washington, Seattle, WA, United States; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, United States.

Abstract

Disruptions to left atrial (LA) blood flow, such as those caused by atrial fibrillation (AF), can lead to thrombosis in the left atrial appendage (LAA) and an increased risk of systemic embolism. LA hemodynamics are influenced by various factors, including LA anatomy and function, and pulmonary vein (PV) inflow conditions. In particular, the PV flow split can vary significantly among and within patients depending on multiple factors. In this study, we investigated how changes in PV flow split affect LA flow transport, focusing for the first time on blood stasis in the LAA, using a high-fidelity patient-specific computational fluid dynamics (CFD) model. We use an Immersed Boundary Method, simulating the flow in a fixed, uniform Cartesian mesh and imposing the movement of the LA walls with a moving Lagrangian mesh generated from 4D Computerized Tomography images. We analyzed LA anatomies from eight patients with varying atrial function, including three with AF and either a LAA thrombus or a history of Transient Ischemic Attacks (TIAs). Using four different flow splits (60/40% and 55/45% through right and left PVs, even flow rate, and same velocity through each PV), we found that flow patterns are sensitive to PV flow split variations, particularly in planes parallel to the mitral valve. Changes in PV flow split also had a significant impact on blood stasis and could contribute to increased risk for thrombosis inside the LAA, particularly in patients with AF and previous LAA thrombus or a history of TIAs. Our study highlights the importance of considering patient-specific PV flow split variations when assessing LA hemodynamics and identifying patients at increased risk for thrombosis and stroke. This knowledge is relevant to planning clinical procedures such as AF ablation or the implementation of LAA occluders.

Keywords: Cardiovascular flows; Computational fluid dynamics; Image-based simulation; Left atrium; Pulmonary veins; Thrombosis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Atrial Appendage*
Atrial Fibrillation*
Heart Atria / diagnostic imaging
Hemodynamics
Humans
Pulmonary Veins* / diagnostic imaging

Abstract

Publication types

MeSH terms

Grants and funding