Heart Rate Danger Zone?

Hey Folks,

Is there any level of Cardio that would be deemed unhealthy for a mans heart? This man is in his late 20s and is 70 lbs overweight. In my late teens and early twenties I was able to run very efficiently, about 48-56 miles/week in 6-7 hours. Since then I've endured an injury which confines me to the elliptical. I had a long lapse (3-4 years) of relative inactivity. Since my latest venture to re-attain strong fitness levels, I have noticed that my lung capacity and strength has weakened considerably. This was to be expected. What I hadn't anticipated was that my non-tangible traits that made me a solid runner have remained intact. Determination, drive, will... Whatever you may call it, I still have it. I find myself running the heartbeat monitor up around 195. I'm able to sustain and function quite comfortably other than the anxiety it causes me when I start realizing how many beats that is.

My Question: Is it safe for a late-20s male, 70 lb over weight (or ever for that matter) to exercise at ~200 BPM for an extended period of time 30-60 mins, assuming this person feels good while doing it?

PS My blood pressure is a bit high, 130/90 on occasion.