Just to show how everyone is different, Metoprolol has worked wonderfully for me. I've cut my dosage from 25 mg to 12.5 mg a day, and daily baby aspirin to only one every other day. I get spontaneous palpatations almost every day, but never higher range than in the 130s BPM, and they stop spontaneously as well, or with some help from vegus maneuvers. Most last for less than 30 minutes. Oh, I'm an active 82yo male and Tai Chi instructor.