I had a Mitral Valve Repair and a Triple Bypass on Oct 9, 2018. In my case Open Heart means the heart was actually cut open. Lot's of nerve pathways cut and my heart had to relearn how to beat properly. Spent 36 hours in the Cardiac ICU in Afib. At the time of the surgery I was 63 years old and had a 3 year habit of daily exercise that probably prevented a Heart Attack, the LAD was 80% blocked.
Recovery. I was shocked at how weak I was after the surgery. Because prior to the surgery I was pretty fit for a 63 year old ex smoker, my VO2Max was 44 at that time. After the surgery walking just 50 feet was all I could manage on the first day I was allowed to walk. Spent 8 Days in the Recovery center before I was released to go home and you weren't released until you demonstrated good physical competance, meaning could you climb stairs.. In regards to exercise I was told that walking was OK but I was NOT to try and test my limits, at the earliest sign of fatigue I was to turn around and head home. It took me a week to work up to walking a mile and after that I started making real gains, after two weeks I was doing 3 mile walks. Four weeks after the surgery I did the Cardiac Rehab, which is basically treadmill, elliptical, or bycycle work to a specific heart rate and defined time. During each workout I was wearing an 8 lead portable EKG linked to monitors at the nurses station. If you let your heart rate get too high you heard about it, if you were slacking off you were asked to push a bit harder. I did 2 weeks of Rehab and was released to go home.
Landmarks, It was 4 weeks before I was released to drive my car and I was told if I got in any type of accident I had to insist in emergency transport to the nearest ER. The next milestone was going back to work, that happened 5 weeks after the surgery. The concern was potential damage to the Sternum, you do NOT want to re-break that healing Sternum. Two months after the surgery I rewarded myself for surviving Open Heart Surgery by purchasing myself a Beretta 686 Solver Pigeon I Sporting. Still shoot with that gun but it's now wearing an adjustable 682 Gold E stock. Shooting a shotgun was not permitted until 6 months after the surgery, my doctors want to be absolutely certain my Sternum was 100% healed before firing a shotgun. BTW I started doing practice mounts after Christmas.
Note, this surgery was the second time I've had my chest cracked. First time was when I was 13 and it was to correct a deviated Sternum. When you have a growth spurt that has you gain 5 inches in 3 months things can go a bit haywire. The first time I was fearful of my chest pain and tried to avoid the breathing exercises I was supposed to be doing. End up with too much fluid in my lungs and then had to undergo mechanical breathing therapy, which is quite painful. Second time around I was enthusiastic about doing my chest exercises and asked they double the inhaler therapy to help keep my lungs clear. As a result my longs stayed good and clear throughout my recovery form the heart surgery. When you are told to cough for the doctor take a deep breath and cough good and hard. It will be a bit painful but you won't bust any stitches and it will help get you started down the correct path. It is critical to keep you lungs clear and that means that you MUST cough when you need to clear your lungs. When they offer the inhaler once a day ask for the treatment twice a day, it willl help keep you from waking up in the middle of the night with a coughing fit, If they don't give you a Cough Pillow, ask for one. Coughing with a pillow held tight to the chest is a lot less painful that doing without. Mine looks like a teddy bear and I still have it. Fail to keep your lungs clear and you will pay a price for it and it will be a lot worse than making the effort to clear your lungs from the start
Finally a regular routine of exercise will speed your progress towards shooting again and long term make shooting easier. You don't have to go out and run marathons, they are actually bad for the heart. However moderate exercise is absolutely glorious for the heart and it's very easy to do. Simply make it a habit to set aside 45 minutes per day and go out for a 3 mile waks at a pace that you are comfortable with but does have you working up a bit of a seat.