Symptoms

The main symptom of supraventricular tachycardia (SVT) is a very fast heartbeat (100 beats a minute or more) that may last for a few minutes to a few days. The fast heartbeat may come and go suddenly, with stretches of normal heart rates in between.

Some people with SVT have no signs or symptoms at all.

Signs and symptoms of supraventricular tachycardia may include:

• Very fast (rapid) heartbeat
• A fluttering or pounding in your chest (palpitations)
• A pounding sensation in the neck
• Weakness or feeling very tired (fatigue)
• Chest pain
• Shortness of breath
• Lightheadedness or dizziness
• Sweating
• Fainting (syncope) or near fainting

In infants and very young children, signs and symptoms may be difficult to identify. They include sweating, poor feeding, pale skin and a rapid pulse. If your infant or young child has any of these symptoms, ask your child's doctor about SVT screening.

When to see a doctor

Supraventricular tachycardia is generally not life-threatening unless you have heart damage or other heart problems. However, in extreme cases, an episode of SVT may cause unconsciousness or cardiac arrest.

Call your doctor if you have an episode of a very fast heartbeat for the first time, and if the abnormal heartbeat lasts longer than a few seconds.

Some signs and symptoms may be related to a serious health condition. Call 911 or your local emergency number if you have an episode of SVT that lasts for more than a few minutes, or if you have an episode with any of the following symptoms:

• Chest pain
• Shortness of breath
• Weakness
• Dizziness