What's so difficult about ECGs--a bundle of what?

In the first in a series of understanding ECGs Dominic Cox and Hamish Dougall take you through the basics

Are electrocardiograms (ECGs) difficult? Should we believe the titles of numerous texts written on the subject, which proclaim “ECGs Made Easy,” “ECGs Made Simple,” or “ECGs So Simple Your Granny's Cat Could Do Them”? We'll let you into a secret. Reading ECGs is not that difficult. A medical student can make the majority of important diagnoses just as well as a cardiologist and probably far better than the average orthopaedic surgeon. (The definition of a double blind study is an orthopaedic surgeon and an ECG.)

At present you may run for cover on seeing an ECG. We hope to show you that there is no need to do this. If you experience a combination of confusion, apathy, and palpitations on hearing strange words, like ECG mapping, signal averaging, and QT dispersion by a consultant cardiologist on a ward round, take heart. Such discussions are intellectual twaddle and completely unnecessary for the majority of practising doctors to understand. All you need is to understand the basics of the ECG and the rest is simple pattern recognition. We hope to show that, with a simple approach to ECGs, you will no longer fear these “squiggly lines” and that they will aid and enhance your understanding of patients on a daily basis in whatever area of medicine you practise.