What is supraventricular tachycardia?

The term “supraventricular tachycardia” (SOO-prah-ven-TRIK-u-lar tak-eh-KAR-de-ah), or SVT, describes several types of fast heart rates that usually aren't dangerous, but can cause troubling symptoms.

What are the symptoms?

Symptoms include a fast heart rate, tiredness, shortness of breath, dizziness, or feeling like you're going to faint. The fast heart rate usually starts and ends suddenly and can last for minutes to hours.

How do I know if I have SVT?

Your doctor may want to do a test that shows your heart's electrical signals. He or she may also want to record your heart's electrical activity. This can be done nonstop for one to two days (using a Holter monitor) or for up to one month (using an event monitor). An event monitor can record your heart's electrical activity all the time or only when you are having symptoms. Your doctor may also refer you to a heart doctor for more tests or treatment.

How is SVT treated?

Treatment is needed when you have serious symptoms, such as dizziness, chest pain, or fainting. Treatment also is needed when SVT could weaken your heart or increase your chances of dying.

Your doctor may treat you with medicine or a catheter ablation procedure. If the medicine doesn't work or isn't needed, a catheter ablation procedure can be done in a hospital. Your doctor will thread a wire to your heart through a vein in your leg. This wire delivers cold or hot energy to your heart to destroy the abnormal tissue that is causing the fast heart rate. This is usually a small amount of tissue.

Where can I get more information?

American Academy of Family Physicians

• Web site: https://familydoctor.org

American Heart Association

• Web site on catheter ablation: http://www.americanheart.org/presenter.jhtml?identifier=4682

• Web site on SVT: http://www.americanheart.org/presenter.jhtml?identifier=3062868

Heart Rhythm Society

• Web site on catheter ablation: http://www.hrspatients.org/patients/treatments/cardiac_ablation.asp