I suffered cardiac arrest in 2006 with the only change in my 51 y/o basically healthy lifestyle was i started taking 500 mg/day of levaquin four days prior to my collapse in front of my students in the classroom. I am a 4th grade teacher - I had suffered cardiac arrest at least three times before I was treated with Arctic Sun therapy to help recover. The heart catheterization afterwards showed no blockage in my heart. There was a good chance, in my opinion, that levaquin could have caused my cardiac arrest. Although not conclusive because I had a tooth infection which was the reason I was prescribed the levaquin and i was taking an said for the discomfort, the back of my mind always comes back to levaquin because i suffered the joint weakness i read in articles of other users of the medication. I also was reminded after the accident that a young person we knew of had died unexpectedly in her sleep a and she was taking levaquin. It makes you think it may have been the levaquin, but no actual proof could be determined by my doctors. However, I will never take this medication again, knowing there are so many other antibiotics on the market to help me.