A cutting-edge technique that allows scientists to zoom in on tiny details in a 3D image of an entire animal heart may lead to new knowledge about congenital heart disease.
Surgery and other interventions can help repair structural heart defects in many of the 1% of infants born with congenital heart disease. But 10 to 25 percent of those children still don’t survive their first year, and 44 percent don’t survive to age 18. The new technique, originally described in an article published on bioRxiv * and now published in eLife, reveals defects in cells and the components they contain found in hearts affected by congenital heart disease. This can lead to treatments to correct these defects and further improve survival.
When pumping blood, the heart chambers fill and then contract to push blood back into the circulation. In order to contract effectively, the heart cells and the tiny muscle fibers inside must be organized with precision.
“When the heart is diseased or has defects, this organization can be lost or partially lost, and the heart can no longer pump blood efficiently, resulting in complications and even death,” says lead author Graham Rykiel, MS, biomedical engineer who conducted the study as a graduate student in a research team led by senior author Sandra Rugonyi at Oregon Health & Science University (OHSU), Portland, Oregon, USA.
By combining two imaging techniques, 3D computed tomography and 3D scanning electron microscopy, the OHSU team were able to create high-resolution 3D images of the entire heart of a chicken embryo and zoom in to study organization within heart cells. They then used this tool to examine the differences between cells and their structures between a healthy, normal chicken heart and a chicken heart with a defect called tetralogy of Fallot, a relatively common form of congenital heart disease in humans. This revealed structural differences between the cellular components in the healthy chicken heart and the heart with the defect.
âOur imaging technology will allow us to study exactly what happens in the heart and its cells when the heart fails or is sick,â said Rykiel. “This knowledge will give us clues to design better treatments for patients with heart defects and other abnormalities.”
The technique will be useful for studying normal heart development in chickens and other animals, and how factors such as drugs or environmental differences might influence congenital heart disease – a goal of Rugonyi’s group for over 15 years. This in turn may help explain how tiny structural differences in heart cells can cause heart problems or heart failure in people with congenital heart disease, even after successful surgery.
“Using our imaging technology on chicks with heart defects, we can begin to understand how the hearts of human babies with similar defects differ from normal hearts and what needs to be done beyond surgery for them. repair and avoid their failure, âconcludes lead author Sandra Rugonyi, PhD, professor of biomedical engineering at OHSU.
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