Wanderer posted a thread including comments on cardiac rehab so in order to avoid hijacking it...
After a summer of strenuous riding I had my fun little attack after 3mi of out and back with a friend trying testing a possible bike purchase. The day before I had done some 12% hills but I knew I had severe plaque and already was on a variety of drugs. In the bike shop (how appropriate) I went down for the count and they put a stent in. My resting HR hovered at 50 and the doc immediately said I could go back to riding as hard as I wanted the day after getting out of the hospital. Maybe he had me wait one or two days.
While at the hospital, prior to checking out, the cardiac rehab people scheduled me in. We had a bit of a back and forth as I told them I was excited to get on their spinning bikes while hooked up to monitors and find out what my max HR was. They were having none of that but I explained I would be going almost directly from cardiac rehab to spinning class where I'd be pushing myself nearly as hard so I might as well push while under their care but they had their protocols.
The next day my cardiologist called and told me he had cancelled my cardiac rehab and explained that I was already exercising at a higher level than anything they would even begin to allow me to do and that the entire diet program they would push was less healthy than the one I had already adopted (no oil vegan) and that frankly I'd be wasting my time. I chuckled and said "thanks". Last week I got back from a biking vacation in Tucson where I tackled Mt. Lemmon (not fast...but I did it) which is 25mi of nearly relentless uphill at 5-8% with 6000+ feet of gain and knocked off 500+ miles which is nothing for a fit 20...or 30...or 40 something but was pretty good for me.
It just goes to show how different we all are. I'm certain cardiac rehab is a critical thing for many people but was happy to learn I was fit enough that it was entirely unnecessary in my case. I have, however, had to get used to the lower HR numbers I see for any given perceived effort and have found that my better heart-oxygen flow has balanced out the limitations my drug therapy has caused with their heart-rate limiting effects.