Multiscale Structure and Function of the Aortic Valve Apparatus

Abstract

While studying the aortic valve in isolation has facilitated the development of life-saving procedures and technologies, the dynamic interplay of the aortic valve and its surrounding structures is vital to preserving their function across the wide range of conditions encountered in an active lifestyle. Our view is that these structures should be viewed as an integrated functional unit, herein referred to as the aortic valve apparatus (AVA). The coupling of the aortic valve and root, left ventricular outflow tract, and blood circulation is crucial for AVA's functions: unidirectional flow out of the left ventricle, coronary perfusion, reservoir function, and supporting left ventricular function. In this review, we explore the multiscale biological and physical phenomena that underly the simultaneous fulfilment of these functions. A brief overview of the tools used to investigate the AVA is included, such as: medical imaging modalities, experimental methods, and computational modelling, specifically fluid-structure interaction (FSI) simulations, is included. Some pathologies affecting the AVA are explored, and insights are provided on treatments and interventions that aim to maintain quality of life. The concepts explained in this paper support the idea of AVA being an integrated functional unit and help identify unanswered research questions. Incorporating phenomena through the molecular, micro, meso and whole tissue scales is crucial for understanding the sophisticated normal functions and diseases of the AVA.