It is very common in the 3rd stage of CPRS/RSD to suffer bouts of fainting as well as raped heart rate. There is a sac that surrounds our hearts called the cardiac sympathetic plexus it is a rich sympathetic nerve structure, and its dysfunction can cause severe chest pain. Chest pain, stroke , Fainting and even heart attacks is not uncommon in the 3rd stage of CPRS. This fact is usually over looked by doctors because most suffers of CPRS are relatively young women in age and put simply we don't have heart problems let alone heart attacks. Proper treatment with alpha blockers as well as sodium or calcium channel blockers is very helpful. Also cervical and epidural blocks are quite effective. Not trying to scare anyone but seems like us CPRS suffers cant get help unless we find the information for ourselves. I myself have been having fainting episodes and rapid heart rate. If you Google the site RSDRX It contains a wealth of RSD information.The RSD puzzle is well worth the reading. I could not believe how may symptoms I wrote off that are symptoms of my RSD.Hope the information at this website helps!!!