Heart Rate

I was curious if any of you found this abnormal: When I do cardio (mainly I run on the treadmill) I always do it an extremely high heart rate. For example today I ran 7 miles in 63:30 (slow, but take into account I had to take 15 months off from running due to a knee injury), and when I was done I measured my pulse and I was in the 180-190 range (46 beats in 15 seconds). Oh, btw, this is the first time in my life I ever did over 5 miles, so go me!
While I generally take a very moderate amount of caffeine before a workout if I’m cutting (100 mg of caffeine) this should not be elevating it this much. Further, I didn’t feel like I was running at more than a slight jog and I could’ve maintained a converation while doing this. I breathe heavy, but I"m definetly not panting or short of breath.
On the other hand, when I up the speed a bit, eg, when I was in better shape I used to run 2 miles in 14 minutes, or 4 miles in 28. My pulse would be around 200 when I came off and I would be completely short of breath and be laying on the floor for 5 minutes. But I could still maintain it for an extended period of time.
Any thoughts?
Jason