atrial fibrillation
"Occasional episodes (one every few years) starting in my mid-30's, up to my mid-50's. In 2004 cardioversion failed to keep me out of AFIB.  Hospitalized for 3 days, then converted shortly after being given a large dose of Rythmol.  Needed max dose of 425 SR (Sustained Release) twice daily, which kept me in sinus 99% of the time.  When the price of the SR skyrocketed a couple of years ago (WUWT?!), I switched to propafenone 150mg every 4 hours. Paying a small fraction of what I used to. I can go months with no episodes, but then have periods lasting weeks with frequent episodes, even daily with no change in diet or activity.  Episodes last anywhere from a few minutes up to around 12 hours, rarely longer. Also on daily aspirin and metoprolol."