Rhythm Library

The heart's baseline rhythm: SA node fires regularly, every P wave is followed by a QRS.

Sinus rhythm at a rate below 60 bpm.

Sinus rhythm above 100 bpm — usually a response to an underlying cause.

Chaotic atrial activity with irregularly irregular ventricular response and no discrete P waves.

Sawtooth flutter waves from a re-entrant atrial circuit (~300/min), usually with 2:1 AV conduction.

Narrow-complex regular tachycardia originating above the ventricles.

Wide-complex regular tachycardia from a single ventricular focus.

Twisting-axis polymorphic VT, often associated with prolonged QT.

Slow, wide ventricular escape rhythm.

Chaotic, disorganized ventricular activity — no cardiac output. Shockable.

Low-amplitude VF — easy to mistake for asystole. Still shockable.

Absence of electrical activity — flat line. NOT shockable.

Any organized rhythm on the monitor with NO palpable pulse. Rhythm looks normal — patient is in arrest.

Very slow, wide, dying complexes. Peri-arrest.

Every P conducted, but PR > 200 ms. Usually benign.

Progressive PR lengthening until a QRS is dropped.

Constant PR with sudden dropped QRS. High risk of progressing to complete block.

Complete AV dissociation — atria and ventricles fire independently.