Arrhythmias
Ventricular tachycardia VT
Ventricular tachycardia, usually shortened to VT, is a heart rhythm problem in which the lower chambers of the heart beat too fast. Because the ventricles are the heart's main pumping chambers, blood cannot be pumped around the body efficiently while the rhythm lasts, and this can lead to a wide range of symptoms. Ventricular arrhythmias are very rare, but VT does occur in patients of all ages and it does need to be assessed and monitored properly.
What ventricular tachycardia is
The heart has four chambers. The two lower chambers, known as the ventricles, are the main pumping chambers. The right ventricle pumps blood to the lungs to exchange carbon dioxide for fresh oxygen, while the left ventricle delivers freshly oxygenated blood to the rest of the body.
Ventricular tachycardia is a condition where those lower chambers beat too fast. When the ventricles beat at that speed, blood cannot be pumped efficiently, and that is why VT can produce such a wide array of symptoms from one person to the next.
VT is not limited by age and is seen in patients of all ages. It does need to be monitored, which is why a fast rhythm arising from the ventricles is recorded and followed up properly rather than assumed to be harmless.
Why ventricular tachycardia is taken seriously
VT can be dangerous if episodes continue for long periods, because a rhythm that carries on is likely to progress to ventricular fibrillation, or VF. In ventricular fibrillation the electrical signals become chaotic and the heart cannot pump effectively.
Ventricular arrhythmias as a group are very rare, but they can be life-threatening if they are not treated appropriately. That is why a suspected ventricular rhythm is investigated and monitored rather than left alone.
Rhythms of this kind often occur in people who have an underlying problem such as coronary artery disease or a structural heart condition. Part of the assessment is therefore looking for a cause as well as recording the rhythm itself.
Symptoms you may notice
Symptoms vary widely from one person to another. Some people are very aware of an episode and others notice very little, which is one reason a recording of the rhythm matters more than the description of it alone.
You may notice one or more of the following.
Several of these symptoms are common on their own and are often harmless. What raises concern is the pattern. Closer attention is paid when palpitations happen during physical exertion, last for prolonged periods, come alongside dizziness, fainting or chest discomfort, or occur in someone already known to have heart disease.
Fainting during exercise, or a sudden blackout that arrives with no warning at all, is always taken seriously and should be investigated promptly.
- Palpitations, or a sense that the heart is racing, pounding or fluttering
- Dizziness or light-headedness
- Shortness of breath
- Fainting, or a blackout with little or no warning
- Chest discomfort
- Fatigue, which people often put down to ageing or lifestyle
How ventricular tachycardia is diagnosed
The diagnosis of heart rhythm issues is usually made with an ECG, or with a Holter monitor, which is a prolonged ECG recording. The aim is to capture what the heart is actually doing during an episode, and that recording is often the key to an accurate diagnosis.
Because VT may not appear during a short clinic appointment, longer monitoring is particularly valuable. Holter monitoring over 24 to 48 hours, or a longer term wearable monitor, can record intermittent symptoms that a single tracing would miss.
An echocardiogram is commonly arranged alongside the rhythm recording to assess the structure and function of the heart, since ventricular arrhythmias often occur in people with an underlying structural or coronary problem.
Once treatment has begun, regular ECGs are carried out to make sure that treatment is successful and remains effective.
How ventricular tachycardia is treated
Treatment depends on how often VT occurs, how long episodes last, and what is driving them. Dr Jogiya is an expert in arrhythmia treatment and in the management of abnormal heart rhythms, and the plan is matched to the individual patient and the symptoms they experience.
The main options are as follows.
Where a pacemaker is the right answer, it is a small device, usually about the size of a matchbox, implanted beneath the skin of the chest and connected to the heart by thin wires called leads. It monitors the heart's rhythm continuously and works quietly in the background. Implantation is a well established procedure, usually carried out under local anaesthetic with light sedation, and most patients return home within a day.
A pacemaker is not the only device used for a fast heart rhythm. A specialised pacemaker or an internal defibrillator may be implanted instead to help control fast heart rates, and implantable defibrillators are also used to manage abnormal heart rhythms in people with conditions such as cardiomyopathy. Which device suits you, if any device is needed at all, is decided from your own assessment.
Alongside any procedure or medication, the underlying cause is addressed wherever one is found, because understanding that cause helps guide the treatment decisions.
- Medication, which can treat short bouts of VT
- Ablation procedures, which remove or isolate the parts of the heart from which the abnormal rhythm originates
- A pacemaker, which can be implanted to regulate the heart rhythm and suppress VT from occurring
- An internal or implantable defibrillator, which may be used where a fast heart rhythm needs to be controlled
When to seek help
Call 999 immediately if someone collapses and is unresponsive or is not breathing normally, or if you have chest pain that is severe or comes on suddenly. Do not wait to see whether the episode settles on its own.
Arrange an assessment if palpitations are frequent or getting worse, if they last a long time, if they begin during exercise, if they come with dizziness, breathlessness or chest discomfort, or if you have fainted without warning. Episodes that feel different from anything you have experienced before are also worth reviewing.
Early evaluation offers reassurance when the cause turns out to be harmless, and it allows treatment to start promptly when a rhythm problem is found. Assessment usually starts with an ECG and a period of rhythm monitoring, with an echocardiogram where the structure of the heart needs to be assessed as well.
This page is general information about ventricular tachycardia. It is not a substitute for individual medical advice, which needs a consultation and your own test results.
More in arrhythmias
Related conditions he treats.
- Atrial fibrillationAtrial fibrillation, commonly known as AF, is a condition where the atria, or upper chambers of the heart, fire chaotic electrical impulses. This leads the muscle to quiver, or fibrillate, instead of beat, so the heartbeat becomes irregular and is often faster than normal. It is one of the most common heart rhythm issues and around 1.7 million people in the UK have been diagnosed with it.
- Atrial flutterAtrial flutter is a heart rhythm problem that affects the upper chambers of the heart, known as the atria. Instead of beating at a normal pace, the atria beat rapidly, but in a regular and organised pattern rather than a chaotic one. Because the chambers do not have enough time to fill properly, blood is not pumped efficiently from the top chambers to the bottom chambers, which is what leads to shortness of breath.
- Atrial tachycardiaAtrial tachycardia is a fast heart rhythm that starts in the atria, the two upper chambers of the heart. An electrical signal emerges from another section of the atria and causes a rapid repeating beat, which means the atria beat very fast. It is one form of supraventricular tachycardia, or SVT, and short bouts of it can be common.
- Bundle branch blockBundle branch block describes a block in the part of the heart's conduction system known as the bundle branches. These branches carry the electrical impulse from the AV node down to each ventricle, and when one of them is blocked the signal reaches one side of the heart before the other, so the two ventricles no longer contract in step. It is a pattern picked up on an ECG, and mostly it is something monitored rather than actively treated.
- First degree heart blockFirst degree heart block is common, and it can affect anyone at any age. It describes a delay in the electrical signal as it travels from the upper chambers of the heart to the lower chambers, rather than a true blockage. Every signal still gets through, which is why many people notice nothing at all and why the condition is usually diagnosed when testing is being done for something else.
- Second degree heart blockSecond degree heart block is a fault in the heart's electrical wiring, not a blockage in an artery. Some of the electrical signals travelling from the upper chambers of the heart fail to reach the lower chambers, so a heartbeat is occasionally missed. There are two types, known as Mobitz I and Mobitz II, and they are treated very differently.
- Sick sinus syndromeSick sinus syndrome, also called sinus node disease, is a condition where the sinus node, the small area of tissue that acts as the heart's own natural pacemaker, is not functioning properly. Sometimes the node will send an impulse as it should, and sometimes it may not fire an impulse at all, or the impulses may be out of sync. Some patients notice symptoms such as palpitations and shortness of breath, and because the node is unreliable rather than permanently stopped, those symptoms often come and go.
- Supraventricular tachycardiaSupraventricular tachycardia, usually shortened to SVT, is a fast heart rhythm that starts above the ventricles, in the upper part of the heart. Symptoms vary widely from one person to another, so some people are very aware of an episode while others barely notice one. Short bouts of SVT can be common, and can usually be treated very easily.