My 89 year old mother is still 'fit', active, cleans her house, gardens, walks etc, but has congestive heart failure with an ejection fraction of 13% to 17%. She wants to fly from UK to Switzerland (one and a half hours) to visit her daughter. She has often flown in the past and is very comfortable making the journey, but I wonder if it poses an additional thread to her already fragile health. Her heart attack was six years ago and she was not treated until about 5 or 6 hours after onset of symptoms, so she clearly suffered damage, and has had bouts of atrial fibrilation since. What do you advise? I would be very grateful for any information you can give me..