Thanks again to bogstandardcomp from the TES Boards.

This Shockwave app shows the full cycle of the heart beat and can be paused at any point. It includes ‘live’ ECG and blood pressure graphs and some tutorials (though I had difficulty getting them to work). Conveniently, it can also be saved using Firefox or Flashcatcher, to be used on the whiteboard.

Derryclare also posted a great link:

Howard Hughes Medical Institute circulation animations.