I have heart rhythm issues: have had them since before Lyme. If you take a combination of Magnesium, Potassium, and Tuarine (an amino acid) you may notice a difference: this combination is used by thousands of people with arrythmias & is very very good for hearts challenged by illness: these three things are even more depleted by illness. You can get Potassium Gluconate (a powder) and Taurine (a powder) from NOW (a reputable supplement company) and Magnesium Glycinate ( a pill: use the Glycinate because it is the best tolerated form of Magnesium - doesn't cause as many gut issues) - it is available from a number of companies (I use KAL). You can take relatively high doses: several grams of the Potassium and Taurine, mixed in water or juice, and 1200 mg of the Mag - with absolutely no adverse affects. You will most definitely notice a change in your heart rhythm.