Ventricular Ectopic Beats
Premature Ventricular Contractions (PVCs)
PVCs are early heartbeats that start in the ventricles, the lower chambers of the heart. They are common, and their significance depends on the individual patient.
On this page
Understanding PVCs
What Are Premature Ventricular Contractions?
A premature ventricular contraction (PVC) is a heartbeat that comes earlier than expected and starts in the ventricles instead of the usual starting point.
Because the ventricles are activated early, the heart has less time to fill and the beat can be weaker. Many people feel an extra or skipped beat.
After the early beat there is often a brief pause, called a compensatory pause. The next normal beat can then feel forceful.
Early beat starting in the ventricle
Educational comparison
Normal Beat vs PVC
This is a comparison of how the heart is activated, not a before-and-after of treatment.
Reference
Normal Beat
The impulse starts in the sinus node, travels through the atria and the normal conduction pathway and activates the ventricles in the expected sequence and timing.
Variation
PVC
An impulse starts within the ventricle, earlier than the expected normal timing, and spreads outside the normal pathway.
Mechanism
How PVCs Occur
Conceptual illustration of an ectopic focus
A PVC arises when a small area of the ventricle produces an impulse of its own before the next normal beat is due. This area is called an ectopic focus.
The reasons differ between patients, and in many people no single cause is found. PVCs can occur in a heart with normal structure and, in some patients, in the presence of underlying heart disease.
What patients may notice
Symptoms
PVCs may cause no symptoms and are sometimes found on an ECG or monitor. When symptoms occur they vary.
Skipped-beat sensation
A pause followed by a stronger beat.
Extra beat
An additional beat between normal ones.
Strong thump
A forceful beat felt in the chest.
Palpitations
Awareness of the heartbeat.
Dizziness
Experienced by some patients.
Fatigue
Experienced by some patients.
Fainting, chest pain or severe breathlessness need urgent medical care.
How they present
PVC Patterns
Isolated PVCs
Single early beats separated by normal beats.
Repetitive PVCs
Two or more early beats in a row.
Bigeminy
Every normal beat is followed by a PVC.
Trigeminy
A PVC follows every two normal beats.
Different morphologies
PVCs may look the same or different on an ECG, depending on where in the ventricle they start.
The pattern is established by ECG and rhythm recordings.
ECG
PVCs on an ECG
- Shows early beats that start in the ventricles
- PVCs often look wider and different from normal beats
- Gives information about their shape, or morphology
The shape of the PVC can give clues about where in the ventricle it starts. Interpretation needs clinical context.
Assessment
How PVCs Are Assessed
Assessment is aimed at documenting the beats and understanding their context.
Confirms the beats are PVCs and shows their shape.
Continuous recording over a period of time.
Longer monitoring
Used where needed when symptoms are infrequent.
Clinical assessment
History, symptoms and examination.
Cardiac imaging
Used where appropriate to assess structure and function.
Rhythm recording
Holter Monitoring
A Holter monitor records the heart rhythm continuously while you go about your day. It is an important tool for PVCs.
- Continuous rhythm monitoring
- Assessment of how often PVCs occur
- Matching symptoms to the rhythm
- Quantifying PVCs over the monitoring period
Quantifying PVCs
PVC Burden
PVC burden describes how much of the total heartbeat over a monitoring period is made up of PVCs.
It is one piece of information among several. It is read together with symptoms, the pattern of the PVCs, the structure and function of the heart and the overall assessment.
There is no single number that decides treatment for every patient. What the burden means depends on the clinical context.
Conceptual illustration of PVC burden over a monitoring period
Looking at the heart
Cardiac Evaluation
Where clinically indicated, doctors may also look at the heart itself, because the findings influence the overall assessment.
Heart structure
Whether the chambers and walls look normal.
Ventricular function
How well the ventricles pump.
Underlying heart disease
Whether another condition is present.
Many people with PVCs have a structurally normal heart.
Mapping
3D Mapping for PVCs
If catheter ablation is being considered, mapping can help to localise where in the ventricle the PVCs start.
A three-dimensional map shows the shape of the chamber and the timing of electrical activation, helping to point to the origin of the early beats.
Treatment approach
Treatment
Treatment depends on symptoms, the pattern and burden of the PVCs and the overall heart assessment.
Observation
Where appropriate, PVCs are followed over time.
Contributing factors
Other conditions and triggers are reviewed.
Medication
May be used in selected cases. The choice is individual.
Considered in selected patients.
This page does not replace medical advice.
Catheter ablation
Catheter Ablation for PVCs
Ablation treats the small area in the ventricle that produces the early beats. Whether it is appropriate depends on clinical assessment.
Mapping
The ventricle is mapped to find where PVCs start.
Focus localisation
The origin of the early beats is identified.
Target identification
The area to treat is selected.
Ablation
Energy is delivered to the target.
Reassessment
The result is checked.
Context
Extrasystoles and Premature Beats
The term extrasystole simply means an early beat. Premature ventricular contractions (PVCs, or VES) arise in the ventricles. Premature atrial contractions arise in the atria and are also common, usually harmless and often felt as a skipped beat.
Their ECG appearance differs, and distinguishing them matters because management differs. An atrial beat is considered here only because it can produce similar symptoms.
Extra beats may become more noticeable at rest or at night, and pauses followed by a strong beat are typical.
If you also have symptoms such as fainting, or have heart disease, tell your physician rather than assuming the beats are benign.
What May Influence PVCs
Lifestyle and Trigger Context
Stimulants
Caffeine, nicotine and certain energy drinks or medicines may make beats more frequent in some people.
Sleep, stress and alcohol
Disturbed sleep, high stress and alcohol can increase awareness or frequency.
Medical contributors
Thyroid disorders, anaemia, electrolyte imbalance and some medicines are worth reviewing.
The effect of triggers varies. Changing habits may help some people but does not always reduce PVCs, and no-one should be blamed for them.
Beyond triggers
Exercise and When Lifestyle Changes Are Not Enough
Exercise
Regular, moderate activity is encouraged for most people. If PVCs increase with exertion, or come with fainting, chest pain or breathlessness, assessment is advised before further intense exercise. Advice on competitive or intense sport is individual and depends on the findings.
When lifestyle changes are not enough
If symptoms persist after triggers have been reviewed, or if PVCs are frequent or linked to reduced heart function, the next steps may include longer monitoring, heart imaging, medicines (see Antiarrhythmic Medication) and, in selected patients, PVC ablation.
Treatment
When Ablation Becomes Relevant
If PVCs are frequent, symptomatic, or associated with reduced heart function, catheter ablation of the origin may be discussed after other options have been considered.
After assessment or treatment
Follow-up
Follow-up depends on the findings and on any treatment given. It may include repeat monitoring, a review of symptoms and discussion of any changes.
Patients are told which symptoms need urgent medical care.
Questions