I am a 31-year-old female with Neurocardiogenic Syncope and Orthostatic Hypotension. I had an ablation for AVNRT four years ago. When I exercise, my heart rate goes up quickly, and I feel dizzy. After trying several medicines, I'm on Cardiazem and Coreg. These are working better than the others. My question is, how can I lose the 25 pounds I need to lose if I can't tolerate walking on a treadmill for more than 15 minutes at a time? I've worn a holter monitor more than once, and the problem can't be found. After jumping on a trampoline for approximately five minutes the other day with my daughter, I checked my heart rate because I could feel it pounding, and it was 180 bpm. I had to be helped into the house, and I was sick the rest of the day. Any help is greatly appreciated.