I have a mechanical aortic valve for 2 years now, I was told by one of my cardiologists, that I HAVE AN IRREGULAR HEART BEAT, BUT NOT A-FIB. LATYELY I HAVE EXPERIENCED SOME MORE PROBLEMS, AND A NEW CARDIOLOGIST TOLD ME, I DEFINITELY HAVE A-FIB? I AM CONFUSED. I ALSO HAVE BEEN TOLD THAT I HAVE A LOW EF RATE (25 -30). WE ARE BOOKED ON A VACATIOON 96 HOUR FLIGHT) NEXT WEEK. iS IT SAFE????