As a masters runner with "Electrical Heart Block" on one side, and instances of irregular heart beat, I have been searching for something to mitigate this problem.
I've been bummed about this. As far as I could tell, I'd eventually need a pacemaker, or at least an invasive procedure involving the scarring of heart tissue.
Then, children's nutritionist Judy Converse (my little sister) recommended Taurine, an amino acid, along with Magnesium to take care of the irregular beat.
I'm delighted that I've returned to regular training without the irregular beat coming back! I was very worried that my training and racing days were over! I'm a former 1:57/4:01 800/1500 man who still hopes for decent age group marks at 55.
I do not think this is common knowledge, so I'm sharing it. I'm no scientist, so check it out for yourself. Also, I certainly hope that Taurine is not a banned substance! I'd welcome any comments on this.