Hey there - I found out 6 years ago when I was 19 that I have mvp. It is a relatively minor heart defect that is fairly common. Mvp is a defect in the mitral valve of your heart where the valve is deformed and doesn't completely close when your heart beats. That causes small amounts of blood to leak back into the heart chamber and creates the murmurs doctors hear when they listen to your heart. Because this is considered a minor defect, it doesn't require surgery and the only extra thing you have to do is to take antibiotics when you go to the dentist to prevent infection of the valve. Its just a minor inconvenience. The classic symptoms of mvp can be rapid heartbeat for no reason (such as when you are resting), shortness of breath, chest pains, lightheadedness, fatigue, etc. All of these symptoms are minor and usually are very brief.
I went to the university doctor complaining of these symptoms and was told nothing was wrong with me. I went home over the holidays and mentioned them to my regular doctor who ordered me to have some tests including an ultrasound of my heart. My doctor suspected mvp but the ultrasound confirmed his suspicions.
It hasn't changed my life at all. I'm just more aware of the symptoms now when they happen (maybe once or twice every couple of months) and I have to be sure to take antibiotics before I visit the dentist. Other than that, you are able to lead a normal life. My doctor told me that it is a defect you are born with and many many people live their whole lives and never know they have it and never have any problems. I hope the diagnosis didn't scare you too much - if you have any questions feel free to let me know