Cardiac rhythms: the 5 families and how to tell them apart

It's easier to learn rhythms in families than as a long list. Most teaching sets group them five ways: sinus, supraventricular, conduction (the AV blocks plus the junctional escape rhythm), ventricular and paced, and arrest. Learn what each family shares, and the individual rhythms fall into place.

  • Sinus
  • Supraventricular
  • Conduction
  • Ventricular/Paced
  • Arrest
The Rhythm Lessons screen showing a 0 of 27 progress tracker, a foundation track, a 367-term glossary, and rhythm families with a lesson for each rhythm

Sinus rhythms

Normal architecture — an upright P before every QRS — with only the rate changing: normal sinus, sinus tachycardia (fast), and sinus bradycardia (slow).

Supraventricular rhythms

Rhythms from above the ventricles: atrial fibrillation (irregularly irregular, no organized P waves), atrial flutter (saw-tooth flutter waves), SVT, and related narrow-complex tachycardias. Afib vs flutter: flutter has regular saw-tooth waves and often a regular ventricular response; afib is chaotic and irregularly irregular.

Conduction rhythms

Where the signal is delayed or blocked between the atria and ventricles — the first-, second-, and third-degree AV blocks — plus the junctional escape rhythm that takes over when the normal pacemaker fails. See the heart blocks guide.

Ventricular and paced rhythms

Rhythms from the ventricles or an artificial pacemaker. A ventricular beat is wide because activation spreads cell to cell, while paced beats are flagged by a pacer spike (wide with ventricular pacing, narrow with atrial pacing). This family holds the slow idioventricular escape rhythm and the paced rhythms; the fast, dangerous ventricular tachycardias are taught with the arrest rhythms — see the dangerous rhythms guide.

Arrest rhythms

The rhythms of cardiac arrest: ventricular fibrillation, pulseless electrical activity, and asystole. A key teaching point: electrical activity on the monitor does not prove a pulse.

Learn all 27 in the app

VitalSim Rhythm teaches all 27 rhythms grouped into these five families — each with a live strip you can drive, a component breakdown, and a quiz — so the families become second nature.

FAQ

What are the main types of cardiac rhythms?

Teaching sets usually group them into five families: sinus, supraventricular, conduction (AV blocks and escape rhythms), ventricular/paced, and arrest.

What's the difference between atrial fibrillation and atrial flutter?

Flutter shows regular saw-tooth flutter waves and often a regular ventricular response; atrial fibrillation is chaotic, with no organized P waves and an irregularly irregular rhythm.

How many rhythms should I learn?

VitalSim Rhythm teaches 27, which covers the common rhythms across all five families — a solid foundation for reading a monitor.

VitalSim Rhythm