左心房流体力学变化介导的心房结构重构在心房纤颤的发生与发展作用及机制

房颤是临床最常见的心律失常之一，严重影响患者的生活质量甚至威胁生命。到目前为止，房颤发生发展的具体机制仍未被阐明。左心房在发生房颤与发展阶段均会现出现流体力学特性的显著改变，并且研究发现左心房结构重构即纤维化在房颤的发生与发展中起到了重要作用。本项目拟采用四维流场磁共振（4D flow MRI）和延迟增强磁共振（DE-MRI）技术作为研究手段，利用已有的慢性房颤动物模型，应用4D flow MRI和DE-MRI技术深入研究不同类型房颤动物模型在房颤发生与发展的不同阶段心房流体力学变化及流场特性与纤维化联系。以接受外科手术的风心病合并永久性房颤患者作为研究对象，探索房颤射频消融术后心房易颤性与左心房流体力学变化和心房纤维化之间的关系，以 “流体力学改变 – 心肌纤维化因子 – 心房重构结构重构 - 房颤的发生及发展”思路为主线，从一个崭新的视角探索房颤发生与发展机制。

Atrial fibrillation is one of the most common and debilitating features of cardiovascular disease, accounting for high amounts of mortality and morbidity. Despite its clinical significance, the specific mechanism of atrial fibrillation has not been fully elucidated as of yet. In the left atrium, the hydrokinetic forces are suspected to be pivotal in development of the atrial fibrillation, because of the left atrium’s complex and unique anatomy and physiology. Our previous study has found that left atrial structural fibrosis plays a vital role in the development of atrial fibrillation. In this study, we use 4D flow MRI and DE-MRI technology to analyze this structural change. Using an existing canine model of right atrial chronic atrial fibrillation, including rapid pacing and mitral regurgitation, we apply the 4D flow MRI and DE-MRI technology to elucidate the relationship between the atrial hydrokinetic changes, flow field characteristics and fibrosis in the animal model of chronic atrial fibrillation at different stages of disease progression. Furthermore, by studying patients with rheumatic heart disease and severe atrial fibrillation, we explore the relationship between atrial fibrillation after the intervention of radiofrequency ablation and associated changes in left atrial hydrokinetic forces and atrial fibrosis. Additionally, according to the paradigm of ‘hydrokinetic—myocardial fibrosis factor—atrial structural reengineering—development of atrial fibrillation’, we explore how atrial structural reengineering changes with respect to the differing atrial hydrokinetic changes. Using this afore mentioned proposed technique, we will be able to investigate the development mechanisms of atrial fibrillation in terms of the atrial structural fibrosis and hydrokinetic changes, and radiofrequency ablation on atrial structural reengineering.