The 12 lead ECG

The grid on this page shows the small and large squares that an ECG is commonly recorded on.
Note that a small square is 1mm by 1mm and a large square is 5mm by 5mm.

It is recommended that you proceed in the following order...

Basic ECG guide
Guide to more rhythms
Guide to axis
NOBEL PRIZE site game (takes 10 mins)
A set of ECG quizzes with answers
Heart block made easy (You tube)
Bundle Branch Block made easy (You tube)

Here is a normal 12 lead ECG with THREE additional rhythm strips at the bottom.

Normal 12-lead ECG