I take bystolic and a diuretic for high blood pressure. I went into the hospital recently for heart palpitations and they only found low potassium and magnesium. They gave supplements for both. I now have very itchy skin and therefore stopped the supplements for the last two days but then the palpitations came back. Which supplement can be the cause of this or is it that my levels may be too high now? Kidneys checked out fine on bloodwork.