Honestly I am afraid to do hot yoga. I know that heat puts an added stress on your heart and I'm afraid to add that to exercise. I just take regular yoga class in a climate controlled room and I'm fine. Those classes can be close to 100 degrees I have heard.
As you were diagnosed with MVP, your question should be put to the doctor who knows your specifics...made the diagnosis.
My guess, given I have no idea what a "hot yoga" is, is that the MVP shouldn't be a problem. Many people live normal lives, again I can't say I know that includes "hot yoga", with MVP.