Alright so about 8 years ago I had a scare like this.
I started to freak out after a night of the white (hard) and long story short I thought I was having a heart attack. Numb left arm, shortness of breath, all in what my eyes seemed like an attack. Well anxiety kicked in and I was at a party and didnt know what to do. I went to the hospital and they monitored my heart and found nothing wrong there. It turned out just to be a mixture of other drugs that day and anxiety that really kicked it off afterwards.
Granted, good coke will do that to you kind of. It can be hard to distinguish between a rush, then the afterfeeling and come down from coke. End of the day they pumped me with some benos and I was good to go. Just be careful, it can be very dangerous to the body. Prolly best to get it checked if problems persist past the amount of time the coke has effect.