I just saw on the news that 3 runners died this weekend in a Detroit marathon from apparent Cardiac problems. All 3 were fairly young and Cardiac arrhythmia is suspected of being a factor. Not bringing this up to scare anyone... simply pointing out that its important to consult your doctor if you have any concerns about how your will be effected by endurance running.
You may be interested to learn that as an endurance athlete you are over 5 times more likely to encounter arrhythmia problems. The EP's know this and there are studies going on to further understand it, but they only have theories as to why.
I have experienced exercise induced afib but it has always self corrected after a brief period of reduced intensity. I have two training partners that went into more permanent A-fib as you described while exercising. They just slowed down and limped home. Kind of low key..."here it comes again" attitude.
With all three of us we have been through all the testing ( Holter, Stress Test, Nuclear Stress Test, Echo-cardiogram, blood test ) that indicated there were no structural problems with the heart. The cardiologist needs to rule out any chance that the arrhythmia is caused by more dangerous heart defect. If you have not been to see a cardiologist, completed these tests, and ruled out other problems, I would not recommend running in a Marathon.
If you are cleared and have a structurally normal heart, I think you need to consider what happens when you go into A-fib during the race and if this is something you can live with. I have run in five marathons and I know how difficult it is to plan and train for this event, and then pull out at the last minute. If you do enter, you should probably carry a cell phone in case you need to call for a ride back. Another precaution is to take aspirin daily as strokes can occur from clots formed during a-fib if it goes on for a while. Best to have your blood already thinned.
As for future marathons there is hope. I think that for endurance athletes one of the best cases of complete recovery is pro cyclist Bobby Julich formally with Team CSC who retired last year at 36. Bobby was diagnosed with RSVT in 1996 and was treated with radio frequency ablations. Bobby went on to place 3rd in the 1998 Tour De France, win a Bronze metal in the Cycling Time Trial in the 2004 Olympics and win the 2005 Paris-Nice Criterium International.
As others have said, it sounds like an episode of lone afib. You should confirm this with the doctor to be sure. As Jerry said, atrial fib has been associated in some studies with exercise, particularly at high training levels. My own experience is that exercise brings on the condition. I'm no doctor but, if I were you, I would take this incident as a shot across the bow and would err on the side of caution and back off a bit on the training. A 2 day episode, especially if it was your first time, is not to be taken lightly. Trust me, you do not want to join the ranks of people living with afib.
Afib begets afib. Do what it takes to avoid a recurrence.
Hi, and welcome. A-fib can come on at any age. A single episode is called lone a-fib. It could have been triggered by something you ate or drank, energy drinks, caffeine, herbs or spices, stimulants, the list goes on. I'm surprised it lasted for 2 days. I've been dealing with it for a long time and I always know when I go into it, But looking back, I could have had episodes I didn't realize I was having. Exercise in itself has never seemed to "cause" my a-fib. Mine started with ephedrine in supplements back in the 90's. If your Dr checked you out you should be good to go. Good luck with your running!
Your question is best put to your doctors.
That said I will venture, while you didn't say, that you heart went into atrial fibrillation (AFib).
This condition has some been found to have some relationship to extreme athletic exertion. AFib is commonly found to be temporary, but it often (usually?) comes back. My guess is you had a bout of AFib, a condition that is sometimes treated/stopped with an electric shock (electrocardioversion).
AFib is usually not life threatening but does affect one's ability to do physical activities (especially running), and can cause blood clots (with a small probability in an short period of time - months) which can cause extremely bad conditions, including death.
Now what did I conclude? I think if your doctors agree it is ok to run, and if they told you you had an attack of AFib, then you should be ok, and if the AFib comes back the worse outcome of that will most likely be poor performance in the race.