01 Nov 2012, BioSpectrum Bureau , BioSpectrum
Singapore: For the first time ever, researchers have been able to visualize in 3-D the stresses induced by flowing blood in an embryonic heart. The technique, which promises to provide new insight into how and why heart defects develop, is described in a paper published in the Optical Society's (OSA) open-access journal Biomedical Optics Express.
The researchers, led by Dr Andrew M Rollins, an associate professor of biomedical engineering at Case Western Reserve University in Cleveland, looked at a particular type of stress in the heart known as shear stress, which is simply the parallel force of one material sliding along another. In the developing heart, shear stress is induced in the heart's own endocardial cells as blood cells rush past them.
Normally, such shear stress helps to control and regulate cellular processes involved in heart development. Even tiny aberrations in the heart beat, however, can alter blood flow patterns and change these developmental forces, leading to congenital heart defects such as abnormal valve formation.
"All previous attempts at shear-stress mapping have been two dimensional, but the 3-D geometry of the embryonic heart is changing hour by hour at these early stages, and the shape of the heart twists and turns as it develops," said Dr Rollins, "so a 2-D projection doesn't really provide a good approximation."
Rollins and his colleagues at Case Western Reserve developed their new imaging method by modifying a technique called Doppler optical coherence tomography, or OCT. The other co-authors on the Biomedical Optics Express paper are Ms Lindsy Peterson, graduate research assistant, Dr Michael W Jenkins, research assistant and professor of biomedical engineering, and Dr Michiko Watanabe, a professor of pediatrics, anatomy, and genetics, all at Case Western Reserve.