I couldn't agree more Akulahawk... Patients often know what their baseline is, or have been in the hospital before and heard someone mention "some kind of block." I work on a telemetry floor with a lot of return customers, so to speak, and the most important thing is to look for changes. Start with the basics, but also be aware that a new block is occasionally indicative of something more serious (or sometimes it's just a new med, or often totally benign!!), but bottomline- don't be afraid to ask! I liked reviewing youtube videos, and Dubin's EKG interpretation book is great.