Potassium and magnesium have some anti arrhythmic properties. Avoidance of stimulants such as caffeine is helpful in some patients. There is a comprehensive review of supplements used in traditionally Eastern medicine (Biomed Research International 4/2017) which documents the published literature on compounds like Beriberine, Ginkgolide, Omega 3 FA, Resveratrol and there is documented suppression of arrhythmias. There are also the potential for pro arrhythmias i.e. potential for causing worsening (sometimes fatal). The products commercially available are of different potencies depending on the manufacturer. When Cardioligists titrate traditional anti arrhythmic, medicines we will check drug levels and EKGs, initially on a daily basis. I would discourage the use of these products unless they are produced by a reputable, preferably American based company and with proper medical supervision (i.e EKG and rhythm monitoring). Hope that was helpful!