Ventricular tachycardia Health Article

Definition

Ventricular tachycardia (VT) is a rapid heartbeat that starts in the ventricles.

Alternative Names

Wide-complex tachycardia; V tach; Tachycardia - ventricular

Causes, incidence, and risk factors

Ventricular tachycardia is a pulse rate of more than 100 beats per minute, with at least three irregular heartbeats in a row.

The condition can develop as an early or late complication of a heart attack. It may also occur in patients with:

• Cardiomyopathy
• Heart failure
• Heart surgery
• Myocarditis
• Valvular heart disease

Ventricular tachycardia can occur without heart disease.

Scar tissue may form in the muscle of the ventricles days, months, or years after a heart attack. This can lead to ventricular tachycardia.

Ventricular tachycardia can also be caused by:

• Anti-arrhythmic medications
• Changes in blood chemistry (such as a low potassium level)
• Changes in pH (acid-base)
• Lack of enough oxygen

"Torsade de pointes" is a form of ventricular tachycardia that is often due to congenital heart disease or the use of certain medications.

Symptoms

If the heart rate during a ventricular tachycardia episode is very fast or lasts longer than a few seconds, there may be symptoms such as:

• Chest discomfort (angina)
• Fainting (syncope)
• Light-headedness or dizziness
• Sensation of feeling the heart beat (palpitations)
• Shortness of breath

Note: Symptoms may start and stop suddenly. In some cases, there are no symptoms.

Signs and tests

Signs include:

• Absent pulse
• Loss of consciousness
• Normal or low blood pressure
• Rapid pulse

Ventricular tachycardia may be seen on:

• Continuous ambulatory electrocardiogram (Holter monitor)
• ECG
• Intracardiac electrophysiology study (EPS)
• Loop recorder

Blood chemistries and other tests may be done.