While not heart-related, I spent most of last summer going through radiation and chemo for cancer, so have a little experience coming back from a major medical experience. All I can say is, take it slow. I rushed back and have played a couple of gigs since, and I'm still not near 100%. First gig back - back in January - I made it through the gig (with a very good friend sitting in as a fall-back should I have faltered), but less than five minutes after the last tune was face-down asleep at a table only to be awoken when my wife poked me and said all the guys had loaded my stuff out into the car and she was ready to drive me home. Humbling, to say the least, and also lent a keen appreciation to the level of kinship I feel for my bandmates. I've put everything on hold till late summer/fall. It's just not worth jeopardizing your health for the music. First things first, and the rest will follow. Mark Karan and his wife Maile have been invaluable assets in getting me through this experience (he is also an oral cancer survivor), and I cannot stress enough how necessary it is to take care of your body first, and let the music follow. You'll come back, but don't push it. We'd all rather you play longer for many years than rush to the stage sooner and sacrifice any aspect of your recovery. As said above, you know your own body best, so listen to it and follow accordingly. Just don't push it beyond what you may be able to reasonably take on...
Best wishes on your recovery!
Seems like I've been here before...
The Road's Facebook Page (including links to tunage) is here:
http://www.facebook.com/pages/The-Road/ ... 200?ref=nf