Is this all the time or just occasionally?
I would see an EP cardiologist. People with IST have high heart rates.
I am not a medical professional, however, you may want to see a doctor or cardiologist. They may want you to take a stress test and see what happens to your heart when you exercise. They will hook you up to ekg and check heart rhythm. They can tell if you have something going on. Do you have high cholesterol, overweight, just starting exercise program? Might be nothing. Check back on this website after you get results. I had high resting heart rate and they put me on Atenolol, beta blocker (worst decision of my life). Atenolol slows your heart down but can depress cardiac function. Also, on Atenolol you will not achieve those increased heart rates necessary for improving cardio fitness, as it slows exercising heart rate, too. I didn't have chest pain on exercise though. Get this checked out and make sure doc's know what they are talking about. I wish I had gotten more info from my doc's. Hope things get better.