Medication and exercise

I have been using an elliptical machine at the gym for a long time before I was diagnosed and put on all these meds. I'm currently on Lamictal, Klonopin, Seroquel and Effexor. The elliptical has a heart rate monitor and my heart rate used to be right around the target zone for my age. Usually between 130 and 150 bpm. Now it always goes up to 170 and sometimes higher and stays there the whole time. This worries me a lot and I often feel dizzy. It's really upsetting because I have been trying to lose weight and was doing really well and now I have actually stopped going because I'm afraid I'm going to have a heart attack or something like that. I have no idea which one may be causing this reaction. Has anyone else experienced anything like this or know which med may be causing this side effect?

It could be one med, could be a combination. I know when I had a a similar reaction when working out on a different cocktail I had to cut back so I was in my target range. Better to be safe. I also checked in with GP to check for high blood pressure, etc. Could be caused solely by meds, some underlying condition triggered by meds or completely unrelated. Important to check. I would note any symptoms and talk to GP and leave a msg with pdoc about seeing GP for symptoms.
Be safe and take care!