heart rate question

After being sedentary for many years I had an MI in early September.  Fortunately, or so I am told, I did not sustain serious heart damage, as my ejection fraction is still 65.  I do have some damage to the bottom of the heart but I was assured it would not result in symptoms.

Since then I have been gradually trying to increase my exercise.  However, I have noticed that even with what seem to be very light exercise (for example, 18 minutes on a treadmill between 2.3 and 2.4 MPH), my heart rate can get as high as 110-120, which to me seems much higher than it should be?  I feel only normal exertion and am not short of breath or lightheaded at this level, and my rate does go down quite quickly once I stop.  My resting pulse is fine, between 60 and 70, sometimes 80 with anxiety or stress.  Is the heart rate perhaps just indicative of my lack of fitness rather than being any cause for concern?  Thanks in advance.

[erijon]

Your heart rate would normally be very high with poor conditioning during exertion or stress. Having said that I don't think 120 BPM is unreasonable at that level of exercise. Keep in mind that you are using one of your large muscle groups and they will have a higher oxygen need so your heart will work harder, how hard depends on your overall condition.

I do 45 - 60 minutes on a treadmill everyday and I usually get 120 BPM at about 3 MPH and I usually top out at 140 -150 BPM at 4 MPH and 5% incline (can't run due do arthritis in my knees) and my max projected heart rate is 170 BPM so I try to stay at about 85 - 90% of that number at most. I don't think your heart rate response is unreasonable, but if you are concerned you should ask your cardiologist.

Hope this helps,

Jon