Today, I was speaking with someone about the importance of carrying around an old EKG (or ECG if you prefer) whenever traveling. If you end up in an ER with chest pain or syncope, it will be very beneficial to have an old EKG with you (unless your problem is swallow syncope).
Digital copies may suffice, but I would suggest paper redundancy in the case of an EKG. Most modern hospitals have Internet-connected computers, but I don't know that they'd let you log in to your Google Health or Microsoft Health Vault to access your old EKG. Maybe they would (they should if they don't).
So do you have a copy of your old EKG? Is it on Google Health or Microsoft Health Vault? Hopefully you also have a copy in your wallet. Make sure to keep an updated PHR (personal health record).