Angelique - this is Kathi from PPMD. Can you give some more information as to how Luc's heart function was measured and a little about Luc (how old is he?)? I can maybe help address your questions and concerns.
Lisa is correct - if it is the ejection fraction, 60% means that 60% of the blood is pumped out of the left ventricle with each heart beat. Pumping out 55-70% of the blood with each heart beat is normal.