Nice voice over and visual explanation of complete heart block from @thevisualnurse! Be sure to check him out 👍 Complete heart blocks in 60 seconds! . Step 1: Is there one P wave per QRS? No? Step 2: Why? (The PR interval tells the story) . In the example above we see an atrial rate of ~50-60 with a ventricular rate ~30, the inherent rates for each, respectively. The variable and changing PR interval confirms that atria and ventricles are each doing their own thing, contracting independent of o