Ed Gud'on ya! Getting through the major league surgery and thinking about climbing! Excellent!
Can't speak to heart surgery but I had a bit of a bout with cancer 20 years ago. Surgery, chemo, bone marrow transplant and radiation treatment. It was a long way back. Passion at the time was ice hockey. Took a couple of years and some concerted effort but got back to playing at my pre-cancer level. Started rock climbing 15 years ago and haven't looked back. Hockey fell by the wayside and I climb year round and relish everyday on the rock.
Only long-term effect is a reduction in my aerobic capacity due to the impact of the chemo on lung elasticity and my heart valves. Makes some approaches a bit of a grunt. But hell with your plumbing now completely roto-rooted you should be better off now than before the surgery!
There is a light at the end of the tunnel. It is the light of the setting sun glinting off of a Rail Trail Ale at the Otter as you sit on the patio after another terrific, magical day of climbing at the Gunks with great friends.
God bless you and keep you Ed and may your enjoy many, many years of all that life has to offer!