I am a 55 year old female, 133 pounds and have always worked out. I teach Zumba 3x a weeks and teach Pound 4x and also workout and additional 3x a week. Recently, during a group circuit workout, my started feeling short of breath and lite headed, then felt like I was going to pass out. After I got home, I synced my Polar fitness watch and it had registered my Hr at196. I had no energy and just didn't feel good the rest of the day. 2 weeks later, I was waiting to start Pound class and I started feeling the same way, I glanced at my fitness watch and my HR was 222, at this time, I was standing in the hall and hadn't started class yet. 5 days later, while in Circuit training my HR jumped to 231. I went to my cardiologist after the first incident, he put a HR monitor on me, (wireless) it came off the next day, I tried to get it back on but again it fell off during working out. I sweat excessively. He was going to put a monitor with wires but my insurance won't pay for it. So he wants me to have another wireless monitor put on on a Fri, so I will wear it on days I don't teach. My question is....1. Is this anything to be concerned about.? And 2. 2 out of 3x this has happened I have been working out.....what are the chances of it happening when I'm not working out.