ANR - CardiacBABYO2 : Manon Denis (2025-2029)

Oxygen is the most important element for survival, and man lives with arterial blood saturation >94%. Congenital heart defects are associated with anatomical alterations that lead to impaired blood flow. For example, Tetralogy of Fallot, a congenital heart defect due to altered cardiac morphology, leads to situations where the baby either has an arterial saturation considered normal (saturation >94%), or has a saturation falling to 70%, a saturation value found in populations living at 5300m altitude (expedition 5300). However, these children tolerate the situation for weeks, even months, before surgery. The survival of these children is surprisingly good for values of hypoxemia often considered incompatible with life. The molecular mechanisms essential to their survival under hypoxemic conditions are poorly understood and little studied, but represent a physiological mystery with far-reaching pathophysiological implications in any context of ischemia and tissue reperfusion. I have built up a biocollection of cardiac and blood samples taken during reconstructive cardiac surgery and blood from children living at 5300m altitude. Using these biocollections, we are trying to understand how these population adapt to hypoxia.