My 10 yr old son has just recently diagnosed with Marfan Syndrome. His aeortic ventrical is enlarged mild to moderate and the right side of his heart is considerably bigger than the left. His doctor has referred to it as enlarged. He has a resting heart rate of about 108. I was told that the right side of the heart being much bigger than the left is a different disorder than Marfan. What is the name for it?