Heart palpitations in pregnancy

Hi all. I'm 25 weeks and for the last week I've had really heavy palpitations and tightening of the chicest like someone is crushing it. I told my obstetrician today who is putting me on a tape to record any irregular heart beats for 24hours. Worries me a bit but at least she's being thorough.  Just wondered if anyone else has had this or experienced palpitations?