Arrhythmias
Ventricular tachycardia
What is ventricular tachycardia?
Ventricular tachycardia is a type of arrhythmia that arises in the ventricles, the heart’s two lower chambers. It causes the heart to beat extremely quickly – sometimes up to 250 beats per minute. A normal heart rate is 60 – 100 beats per minute at rest.
Heart contractions: VT vs normal heart
The very rapid, shallow heartbeats associated with ventricular tachycardia prevent the heart from pumping effectively; blood pressure drops and proper blood supply to the body is interrupted.
An episode of ventricular tachycardia lasting more than about 30 seconds can cause you to loose consciousness. It can be very dangerous – even life-threatening.
Untreated ventricular tachycardia can result in cardiac arrest. Experts believe that it may be responsible for most cases of sudden cardiac death, which kills about 300,000 people per year in the United States.
If you want learn more about a normal heartbeat take a look at Your heart: The basics.
What causes ventricular tachycardia?
Sometimes, people with structurally normal hearts can experience brief episodes of ventricular tachycardia, and in these cases like this it may resolve on its own, but this is unusual.
Electrical signals: VT vs normal heart
Ventricular tachycardia can be the result of heart muscle injury, particularly injury caused by blood-flow blockage. A blockage can interrupt the organized flow of electrical pulses from the atria down to the ventricles and interfere with the heart’s ability to maintain a normal rhythm and rate.
Most of the time serious, life-threatening ventricular tachycardia is seen in people having an acute heart attack, or in those whose hearts have been severely weakened by heart failure.
Common causes of heart damage that can lead to ventricular tachycardia include:
- Heart muscle injury from a heart attack
- Heart failure, specifically left heart failure
- Certain inherited conditions, such as long QT syndrome
To learn more about how your heart’s electrical “wiring” works, take a look at Your heart’s electrical system.
What are the symptoms of ventricular tachycardia?
A very brief episode of ventricular tachycardia may have no symptoms, but if it lasts more than about 30 seconds you may lose consciousness.
Untreated ventricular tachycardia is very dangerous.
The key symptom of ventricular tachycardia is fainting, or loss of consciousness.
If someone you know experiences this symptom you should immediately seek emergency medical assistance.
How is ventricular tachycardia treated?
Your doctor will determine the best course of treatment for your ventricular tachycardia based on its diagnosed cause and the severity of your symptoms.
Treatments for ventricular tachycardia include:
- Surgical insertion of an implantable cardioverter defibrillator (ICD). An ICD will monitor your heart rate and deliver an electric shock to restore your normal rhythm if tachycardia occurs
- In emergency situations, you may be treated with cardioversion (an electric shock) or defibrillation
- Cardiac ablation, which uses electric current to destroy the cells causing the disruption to your heart’s normal rhythm, can be effective in some cases
- Medication: Antiarrhythmic medications can be used to help prevent ventricular arrhythmias
What are the aims of treatment?
The primary aim of treatment for people with ventricular tachycardia is to completely prevent episodes from occurring.
Ventricular tachycardia is a severe and often life-threatening disorder, and if you are diagnosed with it, your healthcare team will want to take urgent and aggressive steps to immediately stabilize your heart rate and then keep it under control long term.