I work at a major cardiac rhythm management (CRM) device manufacturer, and as part of my training we were shown a video of a doctor demonstrating different types of arrhythmias by moving his arms (to represent the atria) and his legs (to represent the ventricles). I thought the video was hilarious but wasn't able to find a copy online. Until today:
It starts out a little slow but gets pretty funny at around 2:00. Despite the sort of silliness of the video, I actually think it's a very effective way of explaining arrhythmias.
Video via this post by Dr. Wes.