I have been having difficult breathing over the past few days which started after a 1 or 2 km walk. I was born with a bicuspid aorta, and every 5 years I have an echocardiogram to check on it. Most recently was last august, and was apparently ok. I also had a 24 hour holter monitor, also ok. But this recent shortness of breath and feeling of tightness in my chest has me worried. Excercise for only 15 minutes on a treadmill made it worse. I went to the doctor today and he said he could not hear anything of concern but im getting a chest xray and blood test tommorow anyway. Should i be really concerned about or am i being paranoid?