Only magnesium taurate doesn't give me heart palpitations despite making me sleepy with all the taurine. Magnesium malate gave me heart palpitations. Magnesium glycinate gave me heart palpitations. There was another one called magnesium chelate made by Albion and distributed through Swanson that didn't, but that might actually just be magnesium oxide.
I had it mentioned to me that if your magnesium levels are already high you might get heart palpitations when you introduce more magnesium. Reply to this thread if this happens to you.