Temperature Dependence of the Cardiac Sodium Calcium Exchanger

Mortality associated with open-heart surgery is two to three times higher in newborns than in adults. Christian Marshall believes this is due to a lack of knowledge about heart function in newborns, including how the neonatal heart responds to surgery. He’s focusing, in particular, on the inability of newborn heart cells to control calcium levels. When unregulated, calcium can initiate destructive events leading to cell death. Marshall is examining the effects of changes in temperature on the sodium-calcium exchanger (NCX), a protein in the heart cell membrane that is key to calcium regulation. Since surgeons need to reduce the temperature of the heart to perform open-heart surgery, and much of the cell damage occurs when warming the heart after surgery, Marshall is seeking a better understanding about temperature effects on NCX. He hopes this will reveal ways to reduce cell death during heart surgery and contribute to a better survival rate for these tiny patients.