Make sure to also check how the cardiac cycle applies to the different parts of an ECG/EKG waveform! In just this one lecture you will learn how the cardiac cycle, blood flow through the heart, and the cardiac conduction system all come together! We will also review the order of the blood flow through the heart step-by-step.Īs we walk through the cardiac cycle, we will also review the conduction system of the heart including the SA node, AV node, bundle of His, right and left bundle branches, and Purkinje fibers. We will use a step-by-step diagram that will be sure to have you understanding the cardiac cycle in minutes! This lecture will walk you through one cycle of the heart.

Systole and diastole are defined by whether the heart is depolarized (contracting) or repolarized (relaxed).