Human Heart Beating

My ultimate goal is to recreate the functions and form of a real beating heart. I found a clip on you tube that shows this is all of its glory……

Cells send signals to the heart to cause contraction. The first contraction happens in the upper chambers of the heart then the second contraction happens at the bottom of the heart. In the video the second contraction is more visible. However if the organ was upright both contractions would be clear. Below is a basis animation of how the heart works, this will help me to break down the most important elements of how the heart moves. I will then be able to start to recreate the unique movements that the heart makes. The heart that i build will be split up into different sections, which will have seperate motions.