Introduction to Ventricular Rhythms


This page provides an introduction to ventricular rhythms and links to training materials on this website.

When the ventricules handle the pacemaking role, ventricular rhythms can be observed on EKG tracings. This website and related websites provide training, practice drills and quizzes related to ventricular rhythms.

There are several type of ventricular rhythms:

  • Accelerated Idioventricular Rhythm
  • Asystole
  • Idioventricular Rhythm
  • Premature Ventricular Complex
  • Premature Ventricular Complex - Bigeminy
  • Premature Ventricular Complex - Trigeminy
  • Premature Ventricular Complex - Quadrigeminy
  • Ventricular Fibrillation
  • Ventricular Tachycardia
  • Ventricular Tachycardia Monomorphic
  • Ventricular Tachycardia Polymorphic
  • Torsade de Pointes

Ventricular Rhythm Types

Accelerated Idioventricular Rhythm

Accelerated Idioventricular Rhythm EKG tracing Accelerated idioventricular rhythm occurs when three or more ventricular escape beats appear in a sequence. Heart rate will be 50-100 bpm. The QRS complex will be wide (0.12 sec. or more).


Asystole EKG tracing Asystole is the state of no cardiac electrical activity and no cardiac output. Immediate action is required.

Idioventricular Rhythm

Idioventricular Rhythm EKG tracing Idioventricular rhythm is a slow rhythm of under 50 bpm. It indicates that then ventricules are producing escape beats.

Premature Ventricular Complex

Premature Ventricular Complex EKG tracing Premature ventricular complexes (PVCs) occur when a ventricular site generates an impulse. This happens before the next regular sinus beat. Look for a wide QRS complex, equal or greater than 0.12 sec. The QRS complex shape can be bizarre. The P wave will be absent.

Premature Ventricular Complex - Bigeminy

Premature Ventricular Complex - Bigeminy EKG tracing

Premature Ventricular Complex - Trigeminy

Premature Ventricular Complex - Trigeminy EKG tracing

Premature Ventricular Complex - Quadrigeminy

Premature Ventricular Complex - Quadrigeminy EKG tracing

Ventricular Fibrillation

Ventricular Fibrillation EKG tracing Ventricular fibrillation originates in the ventricules and it chaotic. No normal EKG waves are present. No heart rate can be observed. Ventricular fibrillation is an emergency condition requiring immediate action.

Ventricular Tachycardia

Ventricular Tachycardia EKG tracing A sequence of three PVCs in a row is ventricular tachycardia. The rate will be 120-200 bpm. Ventricular Tachycardia has two variations, monomorphic and polymorphic. These variations are discussed separately.

Ventricular Tachycardia Monomorphic

Ventricular Tachycardia Monomorphic EKG tracing Monomorphic ventricular tachycardia occurs when the electrical impulse originates in one of the ventricules. The QRS complex is wide. Rate is above 100 bpm.

Ventricular Tachycardia Polymorphic

Ventricular Tachycardia Polymorphic EKG tracing Polymorphic ventricular tachycardia has QRS complexes that very in shape and size. If a polymorphic ventricular tachycardia has a long QT Interval, it could be Torsade de Pointes.

Torsade de Pointes

Torsade de Pointes EKG tracing Torsade de Pointes is a special form of ventricular tachycardia. The QRS complexes vary in shape and amplitude and appear to wind around the baseline.

Training Resources

Ventricular Rhythms Training Module

A good starting point is our ventricular rhythms module, which focuses on the morphologic features and qualifying criteria of ventricular rhythms. The module includes interactive Q&A.

Ventricular Rhythms

EKG Rhythm Tests

Hundreds heart rhythms in this practice test. Test can be tailored for specific learning needs.

EKG Rhythm Tests

Heart Rhythm Quiz also has a heart rhythm quiz that is similar to a written exam. Twenty tracings are presented. Feedback as you progress. Score at the end.

ECG Quiz

ECG Monitor Challenge

Another type of quiz uses a simulated patient monitor. You must evaluate a scrolling waveform rather than a paper tracing.

ECG Monitor Challenge

External References

Free Dictionary