hello, my father is 63 years old and was newly diagnosd with atrial fib a few months ago. he has never had an evaluation and this was his first. they found he has an atrial septal defect that was never discovered as a child. this came as a shock to me as he runs every day about 10 kilometers and is in very good condition for a man his age. most men younger than him wouldnt have the cardiac stamina he has. he does not suffer from HTN and has no physical s/s of CHF although he does have some atrial hypertrophy, but not ventricular. his heart rate has always been 60 to 80 as far as i can tell, without medication, and we dont know when the atrial fib began (i think a long time ago as a result of the atrial septal defect). we took him to the cardiology center in st. petersburg Russia and they told him to stop running. i cant understand why. he has run for the last 35 years, 5 days a week usually. i am a doctor in emergency medicine and i told him to continue running despite the advice of the cardiologist.  I have him on warfarin,  ramipril, and metoprolol and all of his lab values are normal. my question is about him running. should he stop as the cardiologist suggested? my thoughts are he has done this for years despite not knowing of the condition and he is in good health. i simply told him he needs to watch his heart rate while running. any thoughts?

Summarized question: Is running suggested for a atrial septal defect condition?