Ask The Doctors: February 2010

I had a tissue aortic valve transplant two years ago, and today I feel great. The fatigue is gone and I exercise every day. But when I had an echocardiogram, I had an ejection fraction of 55 percent, which was better than my pre-transplant ejection fraction of 35 percent, though still at the low end of "normal." Why is the ejection fraction still fairly low, and can it ever improve?