Definition of Ventricular tachycardia:

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

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.