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Supraventricular Tachycardia (SVT)

Medically reviewed by: Nak Hyun (Tom) Choi, MD

What Is Supraventricular Tachycardia (SVT)?

Supraventricular tachycardia (SVT) is a type of arrhythmia (abnormal heart rhythm) in which the heart beats very quickly.

The abnormal heart rhythm starts in the atria, which are the top chambers of the heart. Supraventricular tachycardia (soo-pruh-ven-TRIK-yuh-ler tak-ih-KAR-dee-uh) often happens suddenly and can last for a few minutes or many hours.

What Happens in Supraventricular Tachycardia (SVT)?

An area in the atria called the sinus node sends electrical signals that tell the heart to beat at a normal rate. They also tell the heart to speed up during exercise or times of stress, and to slow down during sleep.