When I was in paramedic school, I was having some difficulties with some of the rhythm strips at first, especially in measuring waveform distances, as well as a Mobitz 2 heart block. This book helped me put ECG's together. It starts from the very beginning, such as what the waveforms mean, what distances should be for said waveforms, and finally explanations of each rhythm, where they begin (location wise in the heart) and what they mean. At the end of each chapter, it has a review of the rhythm's you just discussed, by interpreting 10-20 strips. At the end of the book there was 200 some random strips. By the end of cardiology, I could read pretty much any strip that was thrown at me, and I occasionally go back and practice, plus reread some information about some of the ECG's we see in the field and what causes them and how to treat them. This book is great, and I would recommend it to anyone going to school to be a paramedic, RN, PA, RNP, or MD.