Unless you are incredibly smart, it may be helpful to review a few things:

• Lead Placement.

• Conduction system in the heart.

• P-QRS-T.... It's not just the alphabet anymore.   

• Identify the complexes. *

• Normal values for various species.

• What is the cardiac rhythm?  Is it normal sinus or some type of arrhythmia? *

       Short-cut to a menu of ECGs from the entire tutorial

    * Information given in these sections was taken from these references