I am in my 3rd trymester in my pregnancie. i development stv. can this be because im pregnant i never had this. doctor gave me beta blocker and dig?

Treatment: Your doctors are treating you, they are the best to answer your questions. From your description the chose appropriate medication.

SVT: Not caused by your pregnancy most likely. It may improve after delivery or not. Seek the advice of a cardiac electrophysiologist. They can give you more information and counsel you on the pros and cons of the different treatments of your condition.