Assessment of the biomechanical changes in cardiac tissue after myocardial infarction with optical coherence elastography

Myocardial infarction (MI) is a leading cause of death and decrease of quality of life in the USA. An immense amount of research and development has been focused on the molecular mechanisms associated with MI, which have led to numerous therapies for treating and repairing cardiac tissue after MI. However, there is a relative lack of information about the changes in cardiac tissue biomechanical properties due to MI. Therefore, there is a direct need for techniques that can measure cardiac tissue biomechanical properties, which would help further develop our understanding of tissue biomechanical dynamics associated with MI as well as aid in the development of therapies that consider biomechanical properties. In this work we utilize noncontact dynamic optical coherence elastography (OCE) to evaluate the changes in cardiac biomechanical properties 6 weeks after MI in a mouse model. We performed complementary analysis based on elastic wave propagation and damping analyses. Our results show that the left ventricle cardiac tissue became more isotropic and softer after 6 weeks in the MI-affected mice as compared to the sham mice based on the elastic wave propagation measurements. The damping measurements also showed that the MI-affected mice had softer left ventricles as compared to the sham mice. Moreover, the damping analysis was able to localize the boundary of the MI-damaged region. These results show that OCE can be a powerful tool for understanding the dynamics in biomechanical changes in murine cardiac tissue and could potentially reveal diseased areas for targeted therapies.