Your son's cardiologist has failed you by neglecting to mention the most important breakthrough in this area in the past decade, which is angiotensin receptor blocker (ARB) therapy for people with dilated aortic roots. They keep prescribing beta blockers, which are relatively worthless, and ignoring the enormous potential for ARBs in people with MFS, EDS, LDS, etc and other connective tissue disorders.
Please google "Marfan and losartan" as a starting point for your research, realizing that losartan is probably the weakest ARB out there and that others are much stronger. I realize Marfan has been ruled out but the mechanism for action in these drugs appears to be the same for other connective tissue diseases.
After reading up on the research, contact the clinic of Dr. Hal Dietz at Johns Hopkins for an evaluation or for a recommendation for a more knowledgeable pediatric cardiologist in your area.
Feel free to contact me with questions.
Nick
My 20 year old daughter has Ehler's-Danlos hypermobility type and has alot of the symptoms you describe your son as having. She is 6'0 tall and has quite a few stretch marks. The joint pain is constant, but, like your son, she considers it to be normal. She has taken a beta-blocker for years and it seemed to slow down the progression of cardiac complications until recently. A beta-blocker should decrease the heart rate and blood pressure, not increase it. He may need his dosage adjusted.
My daughter also has a congenital heart valve defect that, combined with the EDS, has caused her aorta and aortic root to dilate quite a bit faster than usual, compared to most EDS patients. Hopefully, this is not an issue with your son. Her cardiologist felt that without the valve issue she likely would not have had such a large change in her aortic root and aorta dilation. She just had open heart surgery a couple of days ago to replace the valve, repair the aorta, and aortic root and is doing very well.
Although your posting was a few months ago, I hope this is a little helpful in regards to some of your concerns. I ran accross your questions while sitting at the hospital searching for information regarding her surgery.
Michelle
Q:"I guess my question is to anyone who has experienced this or has children with similar conditions".
Our sister forum has participating members that can identify with your medical concerns and experience from having children with health issues. Sorry to hear of your son's condition, and thanks for posting on this forum. Take care, and I wish you son well going forward.
http://www.medhelp.org/forums/Pediatric-Cardiology/show/302
Ken