Supraventricular Tachycardia

Your heart has its own electrical system that controls how fast and how regularly it beats. With each heartbeat, your heart squeezes to pump oxygen-rich blood out to the body and then relaxes to fill with blood again.

For adults, a normal resting heart rate is between 60 and 100 beats per minute. You’ve probably noticed your heart beating faster at times – for example, during exercise or times of extreme stress.

But with supraventricular tachycardia, or SVT, the heart suddenly starts beating too fast, even if you are resting or not active. During an episode, your heart rate may jump to 150 to 250 beats per minute or higher.

SVT is a type of abnormal fast heart rhythm (abnormal heart rhythms are also called arrhythmias). It happens when electrical signals in the upper chambers of the heart get misdirected. There are several types of SVT, the most common being:

• Atrioventricular nodal reentrant tachycardia (AVNRT)
• Atrioventricular reentrant tachycardia (AVRT)
• Atrial tachycardia (AT)

In most cases, SVT is not cause for alarm. But if you notice your heart racing or fluttering, you should get it checked out, especially if it’s affecting your life in any way.

Stay in tune with your heart. Use this condition center to learn more about SVT, its symptoms, causes, and how to get checked out.