For people who have a irregular heartbeat, be sure and get 400 mg. Magnesium Oxide a day. I go to Walgreens and ask the Pharmacist for it. And if you get an irregular heartbeat and it won't settle down, take 500 to 1,000 mg.oOf Taurine. I went several times to the E. R. and had taken Taurine and by the time I was hooked up, I had a heartbeat of a "seasoned athlete! " It really works!