Numerical Study of Atrial Fibrillation Effects on Flow Distribution in Aortic Circulation

Abstract

Atrial fibrillation (AF) is the most common type of arrhythmia, which undermines cardiac function. Atrial fibrillation is a multi-facet malady and it may occur as a result of other diseases or it may trigger other problems. One of the main complications of AF is stroke due to the possibility of clot formation inside the atrium. However, the possibility of stroke occurrence due to the AF and the location from which an embolus dispatches are subject of debate. Another hypothesis about the embolus formation during AF is thrombus formation in aorta and carotid arteries, embolus detachment and its movement. To investigate the possibility of the latter postulation, the current work suggests a parametric study to quantify the sensitivity of aortic flow to four common AF traits including lack of atrial kick, atrial remodelling, left ventricle systolic dysfunction, and high frequency fibrillation. The simulation was carried out by coupling several in-house codes and ANSYS-CFX module. The results reveal that AF traits lower flow rate at left ventricular outflow tract, which in general lowers blood perfusion to systemic, cerebral and coronary circulations. Consequently, it leads to endothelial cell activation potential (ECAP) increase and variation of flow structure that both suggest predisposed areas to atherogenesis and thrombus formation in different regions in ascending aorta, aortic arch and descending thoracic aorta.

A computational simulation platform for designing real-time monitoring systems with application to COVID-19

“…Computational fluid dynamics (CFD) is one of the best solutions for this matter. In recent years, CFD has successfully been applied to numerous biomedical-related projects involving design, validation and proof-of-concept; some examples from the present authors include ( Deyranlou et al, 2020 ; McElroy and Keshmiri, 2018 ; Ruiz-Soler et al, 2017 ; Swanson et al, 2020 ).…”

Impact of heart failure severity on ventricular assist device haemodynamics: a computational study

“…The localization of various lesions including atherosclerosis and thrombosis has been extensively studied and have shown to be related to different local haemodynamic metrics including some of the work of the present authors (Deyranlou et al 2020;Kabinejadian et al 2016;Keshmiri et al 2016;McElroy et al 2016a;McElroy and Keshmiri 2018;Ruiz-Soler et al 2017;Swanson et al 2020). These haemodynamic parameters can be directly derived from the flow velocity fields obtained by CFD-based simulation tools.…”

“…Each outlet is coupled to a three-element Windkessel model in this study, which has been implemented in the solver by the present authors. The threeelement Windkessel (Westerhof et al 2009) has become the most widely used and accepted lumped parameter model of the circulatory system as it tends to produce realistic aortic pressures and flows (Capoccia 2015;Deyranlou et al 2020;Kaufmann et al 2012).…”

“…Despite more reliable methods existing, it is still common amongst the cardiovascular research community to use simpler outlet BCs such as zero-pressure (Cheng et al 2014;Deyranlou et al 2020;Janiga et al 2015;Kabinejadian et al 2016;Karmonik et al 2014Karmonik et al , 2012bMcElroy et al 2016b;Moon et al 2014;Ruiz-Soler et al 2017;Shang et al 2015). Running 'Tests 0-6' using a conventional zero-pressure BC for all outlets produces significantly different results and misleading conclusions when compared against using a threeelement Windkessel model.…”

Numerical solutions for blood flow in elastic vessels

“…[1][2][3][4][5] Simulations of blood flow in vessels are based on the Navier-Stokes equations. [4][5][6][7][8][9][10][11][12] This is a current and important issue utilized in many practical applications, for example, the study of atrial fibrillation effects on flow distribution in aortic circulation, 13 atherosclerosis formation, 14 stroke simulation, 15 and others. [16][17][18][19][20][21][22][23] The review of blood flow modeling is presented in.…”