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I am a 39yr old male. Kept in good shape all my life by running, lifting weights, various sports. I have been doing Triathlons for past 7 years. My normal resting heart rate is 50 to 60 bpm. December 20, 2000, while sitting and visiting with my Dad, I suddenly felt really bad, almost passed out and was taken to the emergency room. After lots of tests such as EKG, MRI, blood
flow study and stress test, Doctors said nothing was wrong. A few months later it happened again. Doctors found nothing. I had intermittent episodes later but November 2001 it happened again and I felt bad for days. Doctor put me on a 24hr holter monitor and found A-fib, A-flutter, long pauses in heart beat(3sec), heart went from 39 bpm to 170 bpm, all this while I slept.
My first doctor said it was tachy-brady syndrome. Recommended a pacemaker and meds. At this point I stopped exercising. I went for a second opinion. He did an echocardiogram and nuclear stress test. The stress test was fine. The echo shown a very slightly enlarged atria cavity and small hole in atria septum wall(he believes was from birth). He put me on tambocor. First week I was ok. The second week, I woke up every morning around 2am in A-fib(was wearing a 30 day event monitor) but never have A-Fib during the day. Later, I tried Sotalol. This slowed my heart rate to 40 during the day, slower at night and did not help. My doctor wanted to try Norpace next. I'm not taking anything right now. Over the past 3 weeks I've had 2 episodes of A-fib that lasted 4 to 6 hrs then back to normal rhythm. I have been diagnosed with pulmonary vein foci and my Doctors recommend oblation (ablation). My Dr says that he feels this oblation (ablation) technique will be making big improvements with in the next year but for now the success rate for A- fib cure is about 50%(at UAB). I still have episodes where, for no apparent reason, I begin to feel bad, very
nervous, dizziness, light headed, some times blurry vision and
uncontrollable shaking but feel nothing unusual with my heart. This occurs about twice a week for a couple of hours to some times a day. These symptoms are what caused me to go seek help in the first place. For all I know I'm still having A-fib in my sleep.

Question - Is this A-Fib life threatening to the point that I should have the oblation (ablation) done immediately or try other medicines?
Question - Why A-fib only at night?
Question - Could slightly enlarged atria cause this A-fib?
Question - Until 4 weeks ago, I worked at a chemical plant around various acids and solvents. I seem to have improved some since I changed jobs. Could exposure to chemicals have caused my problem?
Question - Could the symptoms of sudden nervousness, dizziness, etc. be caused by the arrhythmias?

[CCF-M.D.-DLB]

1. Atrial fibrillation can be life-threatening only if your heart rate gets very fast and you lose consciousness. Frequent or prolonged episodes of atrial fibrillation also increase the risk of stroke. Tachy-brady syndrome with episodes of long pauses in the heart rate could also be dangerous if this leads to passing out.
2. Sometimes atrial fibrillation occurs when the heart rate is slowed, such as during sleep.
3. Enlargement of atria does predispose to arrhythmia.
4. Probably, there is no connection.
5. These symptoms can be caused by arrhythmia.

[TJ38]

How is your blood sugar ?

[RDW]

My blood sugar has been normal. Also, my thyroid test shown to be on the very low end of normal.