I've not had heart issues yet, nor faced surgery. I have had illness and fever in recent years that caused me to be down for 2 weeks, unable to eat, barely able to drink. When I was "better" I was weak as a kitten, and could not do a third of what I was doing just weeks prior...I can not imagine how you feel Spirit. Rest, and let your body tell you when it is ready. Glad to see ya posting