Although Beta Blockers are sometimes prescribed for this condition, in my case Atenolol caused near Syncope. It's a very unpleasant experience. I would suggest getting off of the beta blocker, if it's not working.
I understand how debilitating your problem is. Obviously, it is something that can cause everyday problems. And it is so unexpected. I have the same problem. I see an electrophysiologist (a cardiologist that specializes in rhythm problems) anyway they did a tilt table test. This is a simple test, but it shows whether that is for sure what your problem is. I was prescribed a medication called midodrine. This keeps your blood pressure from dropping. It really has helped me, and hasn't caused anything but a few superficial side effects. Another way that does not involve medication is increasing your salt intake and making sure you are well hydrated. Good luck!
Dear jsc,
The good news is that your episodes have been so infrequent and there are good therapy options that can help prevent further episodes. One such option is a medication called "Levsin" that can be placed under the tongue whenever you feel an episode coming on. Of course sitting or even lying down is also a good way to prevent the fainting. There are a number of doctors who specialize in the treatment of vasovagal disorders. If you are near Cleveland I would recommend Dr. Fouad or Dr. Jaeger here at the Cleveland Clinic. You can make an appointment with either of them by calling the number below. The National Dysautonomia Research Foundation maintains a list of providers who specialize in this area and it can be accessed on their website at ndrf.org. Best wishes and happy public speaking!