Department of Mechanical, Aerospace and Civil Engineering (MACE), The University of Manchester, Manchester, M13 9PL, UK.
Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PL, UK.
Ann Biomed Eng. 2020 Apr;48(4):1291-1308. doi: 10.1007/s10439-020-02448-6. Epub 2020 Jan 14.
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.
心房颤动（AF）是最常见的心律失常类型，它会损害心脏功能。心房颤动是一种多方面的疾病，它可能是由其他疾病引起的，也可能引发其他问题。AF 的主要并发症之一是由于心房内形成血栓而导致的中风。然而，由于 AF 发生中风的可能性以及栓子脱落的位置存在争议。关于 AF 期间栓子形成的另一种假设是主动脉和颈动脉中的血栓形成、栓子脱落及其移动。为了研究后一种假设的可能性，目前的工作提出了一项参数研究，以定量评估四种常见的 AF 特征（包括无心房收缩、心房重构、左心室收缩功能障碍和高频颤动）对主动脉血流的敏感性。通过耦合几个内部代码和 ANSYS-CFX 模块进行了模拟。结果表明，AF 特征降低了左心室流出道的流速，这通常会降低全身、大脑和冠状动脉循环的血液灌注。因此，它会导致内皮细胞激活潜力（ECAP）增加和血流结构的变化，这两者都表明在升主动脉、主动脉弓和降胸主动脉的不同区域存在动脉粥样硬化和血栓形成的倾向区域。
