Optical coherence elastography reveals the changes in cardiac tissue biomechanical properties after myocardial infarction in a mouse model

Abstract

A leading cause of death and decrease in the quality of life in the USA is myocardial infarction (MI). Molecular and genetic analyses have revealed a plethora of information about critical processes involved with MI. However, there is a lack of accompanying information about cardiac tissue biomechanical properties, which may provide additional critical information to understand the tissue remodeling process after MI. In this work, we utilize two complementary noncontact optical coherence elastography (OCE) techniques to assess the changes in mouse cardiac tissue biomechanical properties 6 weeks after the MI was induced. A focused micro air-pulse induced localized displacements, which were detected by a phase-sensitive OCE (PhS-OCE) system. The localized tissue displacement was modeled by a spring-mass damper model to quantify the tissue stiffness. Additionally, the propagation of an air-pulse induced elastic wave was measured at various meridional angles as a complementary measurement of tissue stiffness and anisotropy. The damping results show that the MI caused a decrease in the stiffness of the cardiac tissue. Similarly, the analysis of elastic wave propagation showed that the cardiac tissue became softer and more isotropic after MI. These results show that OCE can detect the changes in cardiac tissue biomechanical properties after MI. OCE may also be useful for developing targeted therapies by identifying regions of cardiac tissue affected by MI.