Charlee, take it from an RN who diagnosed her DH's condition even though the MDs all said he was fine but he actually had a problem similar to yours...aortic valve stenosis, among other things...and required surgery. He has a Bovine valve replacement and 3 weeks after the surgery, he was out using a push mower on a hill (much to the surgeon's unhappiness) and that was over 10 years ago. The only problem he has had since was the need to have his pacemaker replaced. He is almost 80 years old and is still out in this Florida heat doing yard work and other much heavier work every day. When he gets too hot or too tired he rests. He also avoids stress and drama.
The advice below is the best...along with resting and not overdoing. We love you so much and depend on your wonderful fountain of knowledge so be a good girl and know that there are many prayers being sent up on your behalf. If at a later time you have to have valve replacement, just remember, the docs can work magic on you like you do on vintage machines.
Love and hugs,