Chapter 4 - Sinus Rhythms

turn calipers on, then drag the two blue handles onto your landmarks

Step 1 - Caliper and measure it yourself, then reveal the key to check.

Rate

Regularity

P wave

PR interval

QRS

Reveal the measurement key

Step 2 - Name it from memory (think first - no choices shown):

That’s the free sample — four sinus rhythms.

The full Chapter 4 set adds the pauses and blocks, and Chapters 5–12 cover every other rhythm family the same way.