There are several possiblities. 1) The second echo was wrong and your heart function was normal at that time. 2) The second echo was right and your heart function has improved with the rate control provided by the amiodarone. 3) The third echo is wrong and you still have a low EF.
To help sort this out if you were to come to the Cleveland Clinic we would do our own echo which I have a high degree of confidence in. If I had to bet on one though I would take #2. The issue of the MVP is less clear and it is possible it was previously missed but I don't have a good explaination. It may be a good idea to get a second opinion at a major heart center.