Ventricular tachycardia causes your heart to beat too fast, usually at a rate of about 120 to 200 beats per minute. Ventricular tachycardia is a type of arrhythmia (abnormal heart rhythm) caused by faulty electrical signals in your heart muscle fibres.
Tachycardia means a rapid heart rate, usually of more than 100 beats per minute. Ventricular means that the problem starts in the lower chambers of your heart (the ventricles).
Ventricular tachycardia can be life-threatening, especially if other heart problems already exist, such as heart disease or a history of heart attack. However, ventricular tachycardia can occur with an apparently normal heart. This is usually a less serious condition.
Your heartbeat is controlled by electrical signals (impulses), which start in a part of your heart wall called the sinus node and travel through your heart making it contract. The signals travel from your atria (the upper chambers of your heart) to your ventricles (the lower chambers of your heart) through an area called the atrioventricular (AV) node. The AV node helps to synchronise the pumping action of your atria and ventricles.
Ventricular tachycardia occurs when the electrical signals in your ventricles become disorganised, overriding your heart's normal rate and rhythm. This causes your ventricles to contract faster than normal. Your heart then pumps out blood quicker than normal and your ventricles may not have enough time to fill up properly with blood.
You will generally feel well in between attacks. Symptoms during an attack of ventricular tachycardia may include:
If you get these symptoms, this is known as ventricular tachycardia with a pulse. There is another form of ventricular tachycardia where your heart stops pumping blood around your body (pulseless ventricular tachycardia). This is an emergency situation.
These symptoms may be caused by problems other than ventricular tachycardia, however, if you have them, seek urgent medical advice.
If you have heart disease or have had a heart attack in the past, ventricular tachycardia can lead to a life-threatening condition called ventricular fibrillation, which causes cardiac arrest. Cardiac arrest is when your heart stops pumping blood around your body. This is life-threatening and usually fatal unless corrected within a minute or two.
Many conditions that affect your heart or blood circulation can cause ventricular tachycardia. These include:
Certain factors can trigger ventricular tachycardia, such as:
You may develop ventricular tachycardia without having any apparent underlying cause or risk factor.
Ventricular tachycardia is diagnosed with an electrocardiogram (ECG). An ECG is a test that records the electrical activity of your heart. An ECG will be done if you have had a heart attack, have suddenly become unwell with symptoms, such as chest pain and fainting, or if there is anything else to suggest a heart problem.
If you have symptoms, such as palpitations or fainting episodes, your GP or cardiologist (a doctor that specialises in heart conditions) will ask you about your medical history and may suggest you have an ECG. If your ECG test suggests you have ventricular tachycardia, you will need to go to hospital immediately for the following tests.
Treatment of ventricular tachycardia is aimed at stopping attacks, treating symptoms and preventing future attacks.
A ventricular tachycardia attack can sometimes stop by itself. However, if the attack is sustained (lasts for longer than 30 seconds) you may need hospital treatment to stop it.
If your symptoms aren't severe, you may be given an antiarrhythmic medicine, such as amiodarone, through a drip in your arm to get your heart rhythm back to normal. This is known as pharmacological cardioversion.
If you're having symptoms, such as low blood pressure, breathlessness, dizziness and chest pain, or are falling unconscious, it means that there may be an immediate risk of your condition getting worse and your heart going into ventricular fibrillation. This can be fatal. You will need to have an emergency procedure called electrical (DC) cardioversion. In this procedure, a controlled electrical current is applied to your chest via a machine called a defibrillator to help restore your heart to its normal rhythm. You will have a general anaesthetic for DC cardioversion, which means you will be asleep during the procedure.
There are several different types of medicine that can help control your heart rate and rhythm, including beta-blockers, calcium-channel blockers and antiarrhythmic medicines.
If your symptoms aren't severe, your doctor may prescribe a combination of any of these medicines. You may have to take them for just a short period of time until you have another treatment to restore your heart rhythm, such as DC cardioversion. Alternatively, you may be given medicine to take just when you get symptoms.
Always ask your doctor for advice and read the patient information leaflet that comes with your medicine.
Catheter ablation is now a preferred option for many people with ventricular tachycardia. This is when small tubes called electrode catheters are passed into the veins in your groin and threaded up to your heart. Abnormal tissue that is disrupting the electrical signals in your heart is burnt or frozen away.
You may need to have an implantable cardioverter defibrillator (ICD) fitted to detect ventricular tachycardia and restore your heart to a regular, slower rhythm in the event of future attacks.
An ICD is a device implanted under your skin, usually near your collarbone on your left side. It monitors your heartbeat and when it detects that your heart rate is too fast, it will carry out at least one of three treatments described below.
Produced by Alice Rossiter, Bupa Health Information Team, August 2012.
For answers to frequently asked questions on this topic, see FAQs.
For sources and links to further information, see Resources.
This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional. For more details on how we produce our content and its sources, visit the about our health information page.
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