Hi Columbus02,
If you are not satisfied with your physician's response to your concerns consider getting a second opinion. If you are happy with your physician, be sure to quiz her until you are satisfied with the answers, understand your treatment plan, and are comfortable with the decisions made regarding your health.
Since I do not know your medical history, I'm not able to say if you need to take action and be worried about your low heart rate and shortness of breath concerns.
All the best,
Lisa Nelson RD