First, be aware that I am not a medical professional -- just a "user" of a diseased heart. . .
You haven't described your diagnosis, but from the selection of data you've supplied, I'm going to presume that you have aortic stenosis. I am also going to ask if you have been told whether your aortic valve is bicuspid (having two leaflets) or normal (having three leaflets).
The reason I mention this is that there are three typical causes for aortic stenosis (not in any special order):
1) Old age -- not likely you.
2) Rheumatic fever -- not mentioned.
3) Bicuspid aortic valve - if not either of the first two, this is often the cause.
Given all this, most bicuspid valvers, myself included, are asymptomatic until they near or enter middle age. At that time, often in their 50's, a murmur is detected and the medical management process begins. I found out about my murmur in a routine physical at age 54. I have aortic stenosis and a "probable" bicuspid valve, with echo statistics now similar to yours. My only symptom to date is gradual reduction in exercise tolerance over the past 5 or 10 years. I jog 5 days a week, and have slowed down from 7:30 miles to a more sedate 9:15 per mile pace. My cardio has not restricted my heart rate, even when I have indicated that it often goes up to 160 or so under full load. He does tell me to be on the lookout for changes, and if I don't feel good, don't run full speed. He has also restricted my "weight lifting" to 40-50 lbs., but I can do as many repetitions as I want.
I would guess that much is case-specific. I am at what appears to be a similar point in disease progression to yours, and my life has not been dramatically impacted. At the present time we (my cardio and I) describe my situation as "watching and waiting" and that surgery is still some years in the future. I hope to wait a while longer, so as to have as many valve choices as possible.
The usual caveats -- your mileage may vary. Just because I am able to do one thing or another, do not substitute my experience for advice from your doctor. If you are not happy with your doctor and his/her management of your case, though, by all means seek a second opinion.
