Submitted by Dr T on November 22, 2011 – 10:29am
The swelling in your legs can be caused by a variety of causes, one of which includes problems with your heart, or deep vein thrombosis (DVT) in your legs. If it is your heart, there should be other evidence of heart failure such as trouble breathing, lack of energy, early fatigue. An Atrial Septal Defect (ASD) at your age can certainly cause these symptoms, but it may also be incidental to other problems with your heart.
I cannot tell from here what is going on yet, but the echocardiogram was a good start. I expect that DVT has been excluded, but apart from finding the ASD, your heart needs more evaluation.
Get back to me if you need more information. Hope this helps