Shear Stress and Wall Strain Distribution in Human Coronary Arteries In-vivo

strain measurement (right). INTRODUCTION Blood flow induced wall shear stress (SS) plays an important role in the (patho)physiology of the vascular wall [1]. Recently tools became available to study the 3-dimensional SS distribution in the coronary arteries relative to local wall morphology in-vivo [2]. In addition, local strain distribution in the wall can be measured with an ultrasound-based technique called elastography. This strain distribution can be applied to determine local properties of the vascular wall [3]. We combined SS and strain measurements in-vivo to test feasibility of determining vulnerable plaque parameters relative to SS distribution. METHODS In a patient enrolled in a stent study, biplane angiography and an ECG gated stepped pull back with intravascular ultrasound catheter were performed to obtain the 3D geometry of a coronary segment. IVUS images were first recorded with a sheathed catheter (CVIS), which is essential for an accurate 3D reconstruction using the ANGUS method [2]. Subsequently, another IVUS catheter (JOMED) was introduced. IVUS images and elastographic data were acquired during a continuous pullback in the same arterial segment (figure 1). SS was determined by applying computational fluid dynamics, using the 3D reconstructed arterial segment and patient-specific SHEAR STRESS AND WALL STRAIN DISTRIBUTION IN HUMAN CORONARY ARTERIES IN-VIVO