Ventricular Arrhythmia
Ventricular Arrhythmias
Ventricular arrhythmias are abnormal heart rhythms that start in the lower chambers of the heart, the ventricles. They range from extra beats that are often harmless to rhythms that need prompt assessment.
On this page
Understanding ventricular arrhythmias
What Are Ventricular Arrhythmias?
The ventricles are the main pumping chambers of the heart. A ventricular arrhythmia is an abnormal rhythm that starts in these chambers instead of in the normal electrical pathway from the top of the heart.
This page is an overview. It introduces premature ventricular contractions and ventricular tachycardia and explains how ventricular rhythms are assessed and treated in general terms.
Their significance varies widely. Some people have no symptoms and need reassurance and follow-up, while others need further tests or treatment.
Origin of the rhythm in the lower chambers
A range of rhythms
From Extra Beats to Sustained Rhythms
Ventricular arrhythmias are grouped by how they behave. The same person may have more than one type.
Premature ventricular contractions
Single extra beats that start in the ventricles. Often described as skipped or thumping beats.
Non-sustained ventricular tachycardia
A short run of fast ventricular beats that stops on its own, usually within seconds.
Sustained ventricular tachycardia
A fast ventricular rhythm that lasts longer or needs treatment to stop. It needs prompt medical assessment.
The type of rhythm is established by ECG and rhythm recordings, not by symptoms alone.
Extra beats
Premature Ventricular Contractions
A premature ventricular contraction (PVC) is an early beat that begins in the ventricles. After the early beat there is often a brief pause, and the next normal beat can feel forceful.
Reference
Normal Beat
The impulse starts in the sinus node and travels through the normal pathway to the ventricles.
Variation
Premature Ventricular Beat
An early impulse starts within the ventricle itself, producing an extra beat.
Many people have PVCs from time to time. Assessment looks at how frequent they are, how they feel and whether there is any underlying heart condition.
Faster rhythms
Ventricular Tachycardia
Ventricular tachycardia (VT) is a rapid rhythm that starts in the ventricles. It is described in several ways.
Non-sustained
A short run that stops by itself.
Sustained
A longer run, or one that needs treatment to stop.
Monomorphic
The beats look the same on the ECG, which can suggest a single circuit or focus.
Polymorphic
The beats change shape on the ECG and need individual assessment.
Sustained VT, fainting or severe breathlessness need urgent medical care.
Mechanisms
How Ventricular Arrhythmias Arise
Ventricular rhythms can start in different ways. The mechanism matters because it influences the work-up and the available treatments.
Conceptual illustration of ventricular activation
Focal activity
A small area of the ventricle fires early and repeatedly, producing extra beats or a faster rhythm.
Re-entry
An electrical signal travels around a circuit and re-excites the tissue repeatedly.
Scar-related circuits
In some patients, areas of scarring from previous heart conditions can form pathways for abnormal circuits.
What patients may notice
Symptoms
Symptoms vary. Some people feel nothing, and the rhythm is found on an ECG or monitor.
Skipped or extra beats
A pause or a forceful beat.
Palpitations
Awareness of a pounding or racing heart.
Shortness of breath
Feeling breathless during an episode.
Chest discomfort
Pressure or discomfort in the chest.
Dizziness
Feeling light-headed or unsteady.
Fainting or near-fainting
Needs urgent medical assessment.
Tiredness
Feeling unusually tired.
Fainting, chest pain or severe breathlessness need urgent medical care.
ECG
What Ventricular Rhythms Can Look Like on an ECG
- Ventricular beats often look wider than normal beats
- PVCs appear as early beats
- VT appears as a run of fast, wide beats
An ECG recorded during symptoms is the most informative. ECG interpretation needs clinical context.
Looking at the heart
Is the Heart Structurally Normal?
Heart structure assessment
Not every ventricular arrhythmia is linked to structural heart disease, and many occur in a structurally normal heart.
Because the answer influences the overall assessment, the evaluation often looks at:
- Heart structure and pumping function
- Previous heart conditions or scarring
- Family history of rhythm problems or sudden death
- Other contributing factors
Assessment
How Ventricular Arrhythmias Are Assessed
Assessment is built around documenting the rhythm and understanding its context.
Clinical assessment
History, symptoms, family history and examination.
A recording of the rhythm at rest, and during symptoms where possible.
Continuous recording over a period of time.
Extended recording when episodes are infrequent.
Heart imaging
Assessment of structure and function.
Contributing factors
Review of medicines, blood tests and other conditions.
Electrophysiology
EPS and Mapping
An electrophysiology study (EPS) records electrical activity from inside the heart and can help to understand a ventricular rhythm when it is clinically indicated.
Mapping may be used to identify where a rhythm starts or which tissue supports a circuit. Where relevant, it can include looking at areas of abnormal tissue.
Activation mapping and substrate mapping are different approaches, and the choice depends on the rhythm and the patient.
Treatment approach
Treatment
Treatment depends on the type of rhythm, symptoms and the overall heart assessment. Not every patient needs treatment.
Observation
Some extra beats are monitored over time and need no treatment.
Contributing factors
Where relevant, other conditions and triggers are reviewed and addressed.
Medication
Medicines may be used to reduce episodes or symptoms where clinically appropriate. The choice is individual.
In selected patients a defibrillator may be considered.
This page does not replace medical advice. Anyone with ongoing episodes together with fainting, chest pain or severe breathlessness should seek urgent medical care.
Catheter ablation
Catheter Ablation for Ventricular Rhythms
Catheter ablation treats the part of the ventricle that triggers or maintains a rhythm. Whether it is appropriate depends on clinical assessment.
EPS
The rhythm is studied from inside the heart.
Mapping
The origin or circuit is located.
Target identification
The tissue responsible is identified.
Ablation
Energy is delivered to the selected area.
Reassessment
Electrical behaviour is checked again.
After assessment or treatment
Follow-up
Follow-up depends on the rhythm and any treatment given. It may include repeat ECGs or rhythm monitoring, review of symptoms and discussion of any changes in treatment.
Patients are told which symptoms need urgent medical care. For procedure preparation and recovery, see the patient information pages.
Questions