Mechanical stress caused by blood flow, such as wall shear stress (WSS)
and its related parameters, is key moderator of endothelial degeneration. However,
an in vivo method to measure WSS on heart valves has not been developed.
The result that Vector flow mapping method using intraoperative epi-aortic echocardiogram is an effective way of measuring WSS and OSI on normal aortic leaflet in vivo, allowing for better understanding of the pathophysiology of aortic valve diseases.

Hideyuki Hayashi, Koichi Akiyama, Keiichi Itatani, Scott DeRoo, Joseph Sanchez, Giovanni Ferrari, Paolo C. Colombo, Koji Takeda, Isaac Y. Wu, Atsushi Kainuma, Hiroo Takayama, "A novel in vivo assessment of fluid dynamics on aortic valve leaflet using epi-aortic echocardiogram", Echocardiography, (2020) https://doi.org/10.1111/echo.14596.