Question about a job

Hi im from new jersey and i was looking and the local hospital near me is hiring for er techs.. they will take you with your emt-b cert which is what i have but they also want you to have your Telemetry certification may i ask what exactly that is and how one would obtain such a cert?
My hospital provides a 4-day basic dysrhythmia course that I had to take and pass in order to work as tele monitor tech and now as a CV tech. All ICU, ER, PACU, cath lab, and general cardiac floor nurses are required to take it as well. Then there's a more in-depth class on EKG interpretation my hospital also offers. I'm not sure if that's how it's done in your area, but maybe you could call some local hospitals' education departments and ask if they offer something like that that non-employees can take through them for a fee, or where in the community you could get similar training.