EsthersDoll,

Heavy cardio, yoga positions with the head down, and other intense tasks may not ever be in your future. I can do strenuous work but have limits to how I can position my body. Too much head down or head lower during efforts can be problematic.

You may try starting with a chair bike pedal exerciser. Here is a link to some models available. http://www.nextag.com/chair-bike-pedals/compare-html

By exercising without foot plant impacts from walking nor visual or auditory over-stimulation at a gym, you can know that any symptoms are just from the exercising.

Track the amount of time and the tension settings you use and your blood pressure and pulse before, during and after the exercise. If you become symptomatic, rest and try a lower level of effort the next time. When you find the no-symptom exercise level, do this exercise for a few weeks before increasing your effort by a small amount, maybe 10%.

This is basically the Buffalo protocol.

Hope this helps.

My best to you.