The EKG Cheatsheet!
 
Covers the following rhythms:
 
Normal Sinus Rhythm 
Sinus Bradycardia
Sinus Tachycardia
PAC
A Flutter
A Fib
PVC
V Tach
V Fib
 
Features the following sections for each rhythm:
 
Rhythm Visual
Rate
Rhythm
P waves
P to QRS Ratio
PR Interval
QRS Complex