Hi, Liam,
It sounds like you're on the right track so far. I'd keep up with exercise, to the limits of what you can tolerate - right up until you head to the hospital for the surgery. I was 63 when I had my valve replaced, and was jogging until about a week prior to surgery (that's when I had the pre-op angiogram, and had to drop the running for a bit). Stay healthy and in good shape until surgery. I feel that this helps you to recover better and sooner.
I agree with almost_hectic about cardio rehab. As I mentioned, I went into surgery in pretty good shape for an old gym rat, but the surgery took the wind out of my sails. (Read my old posts to see how many speed bumps I hit on the recovery road.) I finally started rehab at 12 weeks out from surgery, and by the end of the 12-week program, I was back in the gym 5 days a week at almost my pre-op intensity. My rehab program was 3 days a week for 12 weeks, and on the "off" days I just went to my own fitness center and did the same routine as I did at rehab, just without the supervision. I wear a heart rate monitor, so I could at least ensure that my heart rate was behaving as it did in the rehab sessions. Rehab proves to you how much you can do without harm, and the presence of trained technicians to monitor you gives you confidence.
A couple of things from my personal experiences:
1. The meds used during surgery and during your first few weeks of recovery will include pain meds. These will wreak total havoc with the digestive systems of many patients. They brought mine to nearly total stop. I suffered so much digestive distress that 4 weeks after heart surgery I had to be readmitted to the hospital to deal with my intestinal distress. Don't let this happen to you. Talk with your doctors about what you can do to avoid intestinal slow-down issues. One of our members (pellicle) recommends daily ingestion of a serving of kimchi (Korean cuisine), and swears that this kept him in fine shape. I recommend something more palatable to myself - Miralax. After my repeat trip to the hospital for digestive issues, the docs recommended daily use of Miralax to keep things moving. Your docs may recommend a different product, but do have the conversation so that if your system stops, you are prepared to deal with it before you need to go back to the hospital.
2. Keep track of your moods and mental situation. We haven't talked much about it lately, but depression is quite a common side effect after heart surgery. You need to read a bit about the symptoms and be honest with yourself in assessing your condition. Most patients are able to deal with minor depression just by being able to recognize it and to take simple steps to control their condition (the psychologists call this "behavioral modification"). I'm not a psychologist, but I recommend that you remain aware of the potential and take action as appropriate. In these cases, it is not any sort of stigma to seek professional help if you need it. Most of us recognize the simple symptoms like crying for no reason, and we just live with it and laugh about it. . . as long as it doesn't linger for months and months. You can find a good bit of information about this on this site, too.
Recovery will not be as easy as it looks on TV - where the patient is having a party in their hospital room the day after surgery. It isn't that bad, either. I was home after 9 days (complications, remember?), and by then I was fully able to get into and out of bed without help, walk up and down stairs multiple times daily, and to do most personal care tasks unaided. I had little stamina at first, but things progressed well and I was back to work part-time by about 5 or 6 weeks. By 4 weeks or so I was walking a mile at a time on an indoor track while my wife did her workout routine at the fitness center.
One of the most important aspects of recovery is your personal attitude. Just think of it this way. . . "If you think you can, you will. If you think you can't, you're probably right." YOU CAN!