atrial fibrillation
"I have been taking Metoprolol for three years.  I had one episode two years ago, went to ER and it converted with an IV of something.  Was up to 170 when I got there.  I started taking 25 milligrams of Metoprolol twice a day and a lose dose aspirin once a day.  I had another episode last September.  They gave me Fleccinide (spelling?) and it reversed on its own.  The first time, I had very stressful day, drank huge amount of coffee, and didn't sleep well the night before.  The second time, I mowed both the front and back yard and did five minutes on stationary bike.  Other than that, the metoprolol has controlled it and I try to avoid stress, sleep well, and don't mow both yards at once.  The only side effect I have is fatigue."