My Emergency scare and hospital visit!

My Emergency scare and hospital visit! 
This morning was spent in the er with my son.  He gave me the scare of my life. 
He has been really tired lately but I chalked it up to being a teenager, since that is normal for a teen. Anyway this morning he couldn't get moving but finally he got going and his belt broke so we stopped at Walmart to get. He said his throat felt funny so I told him to go get something to drink I really didn't think much of it. I was picking out a belt and he came back his heart was beating so fast you could see the veins in his throat. I felt his chest and it was too fast to even count. Scared the heck outta me. I grabbed him and we went to the only place I know here which is the instant care and they weren't open so I banged on the door and showed the lady. She said their was no one thieir and couldn't help. I told her I just saw the doctor walk in. She said they couldn't help and would send him to the hospital. I was so mad I grabbed her hand and let her feel his chest and she gave us directions to the hospital. Well I couldn't find the er since I have never been to this hospital since we go to the in the next town. Well I finally get to the hospital and and find the er by the time they sign him in, get him to the back, the dr looks at him, they do the ekg well by that time its almost an hour later and everything was back to normal. His heart rate was down to like 112 which is high for laying down but not a cause for alarm. they did a cbc and enzyme test which were all normal. The doctor says he doesn't know what it was and sends him home. No referal or anything.