How to doctors study the electric system of the heart?
A common way of looking at the electric system of the heart is the electrocardiogram (EKG). By placing several electrodes on different parts of your body the elecrtric wave that is generated inside the heart is picked up and printed on a piece of paper called an electrocardiogram. Doctors read this print out to understand what is going on with your child's heart.

Normal Electrocardiogram (EKG)
Here's an animation to illustrate normal electric changes in the heart during a heart beat:

As the electric impulse is generated in the SA node and activates the Right and Left Atrium it generates a little bump or wave on the electrocardiogram called a p wave. Between the p wave and before the onset of the q r s which is the contraction in the Ventricle there is a little delay which is caused by the AV node. When the electric impulse arrives at the lower parts of the heart (ventricles) it activates both ventricles and causes the q r s complex. When the heart relaxes it produces the t wave.

If you would like to read more about the electric system of the heart, click here to visit our "How the Heart Works" pages.