What is ventricular tachycardia?

Ventricular tachycardia (VT or V-tach) is a type of abnormal heart rhythm, or arrhythmia. It occurs when the lower chamber of the heart beats too fast to pump well and the body doesn't receive enough oxygenated blood.

A normal heartbeat begins with an electrical impulse from the sinus node, a small area in the heart's right atrium (right upper chamber). Ventricular tachycardia begins in the lower chambers (ventricles) and is quite fast. When it lasts only a few seconds, ventricular tachycardia may cause no problems. But when sustained, ventricular tachycardia can lower the blood pressure, resulting in syncope (fainting) or lightheadedness. Ventricular tachycardia can also lead to ventricular fibrillation (a life-threatening arrhythmia) and cardiac arrest.

What causes ventricular tachycardia?

Structural Heart Disease

Ventricular tachycardia most often occurs when the heart muscle has been damaged and scar tissue creates abnormal electrical pathways in the ventricles. Causes include:

• Heart attack

• Cardiomyopathy or heart failure

• Myocarditis

• Heart valve disease

Idiopathic Ventricular Tachycardia

Sometimes, people with no known heart disease can develop ventricular tachycardia, often due to an irritable focus — when cells outside the sinus node start generating an electrical impulse automatically on their own. This form of ventricular tachycardia is easier to address and is usually not life threatening.

Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a genetic condition that can cause a fast abnormal heart beat from the ventricles. CPVT may cause a loss of consciousness or sudden death due to the lack of blood pumped to the body. This inherited disease is common in individuals who have a family history of syncope, also known as fainting.

What are the symptoms of ventricular tachycardia?

When ventricular tachycardia lasts a short time, there may be no symptoms except palpitations — a fluttering in the chest. But ventricular tachycardia lasting more than 30 seconds may cause more severe symptoms:

• Chest pain

• Dizziness

• Fainting (syncope)

• Shortness of breath

• Cardiac arrest

How is ventricular tachycardia treated?

• Radiofrequency ablation: a minimally invasive procedure to destroy the cells that cause ventricular tachycardia; less effective when there is structural heart disease

• Implantable cardioverter defibrillator (ICD): an implanted device that delivers an electrical pulse to the heart to reset a dangerously irregular heartbeat

• Medication: A number of antiarrhythmic medications are used to prevent ventricular tachycardia. These include:

  • Sotolol

  • Flecainide

  • Propafenone

  • Amiodarone

Learn more about arrhythmias or visit the Johns Hopkins Electrophysiology and Arrhythmia Service.