Should I be concerned about my marfan syndrome?

Yes, you do need to be concerned about your Marfan Syndrome. BUT, not to the point where it is exacerbating your panic attacks. You need to make regular appointments with your specialist physician to have echocardiograms to monitor your heart and check for aneurysms. Aneurysms are when a blood vessel bulges out at some point instead of being more linear like a straw. (Like a long thin balloon you blow up a little bit, where a bulge comes out, but most of it is long and thin). This is a high risk/probablilty with your syndrome. The problem comes in when the 'bulge' is so big, the vessel becomes so weak it can tear, and you could bleed from that area very quickly. But if you routinely have this checked, they can monitor for this condition and you could theoretically have surgery to fix this when it becomes too serious to wait any longer. As for your chest, it is a common trait w/ Marfan and I wouldn't get too excited that your chest is a bit different than other people w/ this syndrome. As for your panic attacks, these seem to really be effecting your quality of life, and a psychiatrist can assist you with this. Good luck.