Chest Pain With Fast Heart Rate. EKG Showed Extra Heart Beats. Prescribed Pepcid. Cause And Cure?

Question: My 8 year old daughter is having chest pains. Sometimes they are on on the left side and at times on the right side just above and to the left of her nipple. She complained of hurting this morning and said it felt like her heart was racing and fluttering. she said that the pain felt like someone was squeezing her chest and then suddenly jerking it hard. She is a worrier and has been under alot of stress worring about a tonsilectomy. She is also sprouting breast buds. The nurse said she had an irreglular hearbeat. We had never been told that before. THE DOCTOR RAN A EKG and said there was a couple extra beats and set her up with a pediatric cardiologist. She was prescribed Pepcid. After taking that she complained of chest pains that evening but as she was explaining to me the location ( right side chest) she burped real loud 3 times. I asked her if her pain went away and she said yes. This has been going on 3 days. After this mornings episode we took her t oa different doctor. He ordered blood wThe pain my daughter describes ork and halter monitor and echo cardiogram. But did not say much about the ekg that was given 2 days ago or what all this may be. Her mother has thyroid and female hormone issues and suffers from panic attacks and irregular heartbeats with chest pains also. Can you help?