Does Taking Percocet Cause Worsening Of Mitral Valve Prolapse?

I have been prescribed Percocet 10/325 for the last two years now for a botched knee surgery that keeps me from walking, running, bending at the knees, getting up, ect. I have been diagnosed with Mitral Valve Prolapse 5 years ago. From October to now (April), my Dr. says that my MVP has gotten significantly worse, and I have been having chest pains often. I am otherwise a very healthy 27 yo woman. Could the Percocet be the cause of my MVP getting worse? I take 2-4 tablets a day, depending on the intensity of my pain, or difficulty walking. I no longer get dizzy, or a 'high' from them anymore, as I guess I have gotten a bit of a tolerance from how long I have been taking them, but I still get pain relief from them. I just want to know if they can be affecting my heart, or making it worse.