I have these and they really used to freak me out. You can feel your heart skipping and sometimes it makes you have to catch your breath. It s very unsettling. I talked to my Dr. and I wore a monitor for a week. Unfortunately nothing showed up. I then wore another type of monitor for a month where it would constantly monitor my heart and if I had a palpitation I would press a button and it would record and retain the last minute of my heart rhythm. I would then call a phone number and transmit the results. In the end I had several heart tests run including a stress test, EKG s and sonogram. My Dr. eventually told me that I was having benign PVC s or Pre-Ventricular Contractions. He said they were harmless and many people have them...some more than others. A woman I work with was having hundreds of them a day for a while so she started taking medication which helped. For me it ended up that I also have high blood pressure and needed medication for that and a side affect of it is that it regulates heart rhythm so I haven t had them for a long time now...except occasionally. If you re worried be sure to get it checked out. It could be a valve problem or murmur, but you might also be one of the many people that have these totally benign PVC s. Concerning the vitamins you take, I have a perpetually low Magnesium which helps regulate heart rhythm. Perhaps you have this or a low Potassium and taking the vitamins helps with this. Best Wishes!!! :)