| Autor: |
Salman HE; Biomedical Research Center, Qatar University, Doha, Qatar.; Department of Mechanical Engineering, TOBB University of Economics and Technology, Ankara, Turkey., Alser M; Biomedical Research Center, Qatar University, Doha, Qatar., Shekhar A; Department of Biomedical Engineering, Cornell University, Ithaca, NY, USA.; Regeneron Pharmaceuticals, Tarrytown, NY, USA., Gould RA; Department of Biomedical Engineering, Cornell University, Ithaca, NY, USA., Benslimane FM; Biomedical Research Center, Qatar University, Doha, Qatar., Butcher JT; Department of Biomedical Engineering, Cornell University, Ithaca, NY, USA., Yalcin HC; Biomedical Research Center, Qatar University, Doha, Qatar. hyalcin@qu.edu.qa. |
| Abstrakt: |
Congenital heart defects (CHDs) are abnormalities in the heart structure present at birth. One important condition is hypoplastic left heart syndrome (HLHS) where severely underdeveloped left ventricle (LV) cannot support systemic circulation. HLHS usually initiates as localized tissue malformations with no underlying genetic cause, suggesting that disturbed hemodynamics contribute to the embryonic development of these defects. Left atrial ligation (LAL) is a surgical procedure on embryonic chick resulting in a phenotype resembling clinical HLHS. In this study, we investigated disturbed hemodynamics and deteriorated cardiac growth following LAL to investigate possible mechanobiological mechanisms for the embryonic development of HLHS. We integrated techniques such as echocardiography, micro-CT and computational fluid dynamics (CFD) for these analyses. Specifically, LAL procedure causes an immediate flow disturbance over atrioventricular (AV) cushions. At later stages after the heart septation, it causes hemodynamic disturbances in LV. As a consequence of the LAL procedure, the left-AV canal and LV volume decrease in size, and in the opposite way, the right-AV canal and right ventricle volume increase. According to our CFD analysis, LAL results in an immediate decrease in the left AV canal WSS levels for 3.5-day (HH21) pre-septated hearts. For 7-day post-septated hearts (HH30), LAL leads to further reduction in WSS levels in the left AV canal, and relatively increased WSS levels in the right AV canal. This study demonstrates the critical importance of the disturbed hemodynamics during the heart valve and ventricle development. |
Full text from SpringerLink