This may sound like a pathetic waste, but i have had a gambling addiction for several years. Now I have been diagnosed with murmur and valve issues. There is no question this was caused by the stress of gambling. I brought it on myself. However, different personalities react in different ways, I had two friends who joined the army in college, one was successful and one could not handle the pressure. Different personalities react differently. The same can be said of teaching. Some personalities get nervous in front of a room. Can it heal? I do not know. I pray that it does. There should be a warning label like on cigarettes: STRESS CAN LEAD TO ACCELERATED AILMENTS. May there be a complete healing to those in need.
I am not a doctor.
The short answer is no, stress doesn't affect the valve.
If you have high blood pressure, this can make the valve leak more than with normal blood pressure. You would have your condition even if you didn't have PTSD.
First of all, thank you for putting your life on the line. My Dad was Navy, 28 years, in Viet Nam twice. So I'm not surprised you have PTSD considering what you've been through. War is never easy, never pretty.
I'm not sure if stress can make a valve condition worsen. Then again, I'm thinking everyday stress that we have like traffic jams and annoying co-workers. Perhaps the stress you experienced raised your BP levels for long periods of time and the stress hormones released probably had an overall impact on your body.
I hope someone who really knows the answer will chime in. Welcome home and I hope your heart is healing nicely.