Left arm tightness/ pain

On and off i have been having intesne and mild left arm numbness/pain. Im only a 21 yr old male. I have a history of PVC's and afib. notinh to big. I have had a stress test, Echo, 24 hr moni all about a year ago all came out ok. the left arm and jaw pain just started about 2 weeks ago on and off. Last night i got it so bad along with chest pain that i called 911 and was rushed to the ER. A EKG confirmed i was not having a heart attack..... I still have the left arm tightness and numbness and it is getting worse. its random but last all day. Anybody else have this and if so what can be the cause. thanks

I do have severe reflux. That mimic heart attack pain at times but the let arm thing is new. and i have appt on thusrday for a echo of my heart.