Supraventricular Tachycardia

Supraventricular tachycardia (SVT) is an abnormal, rapid heart rhythm that starts in the upper chambers of the heart, called the atria. In a normal heart, electricity travels from the atria, through the atrioventricular (AV) node to the lowers chambers, called the ventricles. This transmission produces a regular heartbeat of 60 to 100 times per minute. In SVT, the heart beats too quickly — up to 300 beats per minute — preventing the heart from filling completely with blood. As a result, the body doesn't receive the blood volume it needs to function properly.

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There are many different forms of SVT, including:

  • Atrial fibrillation, the most common SVT, occurs when multiple sites in the atria fire impulses in an irregular fashion. As a result, the heart can beat very quickly and ineffectively.
  • Atrial flutter is a rapid heart rhythm caused by an extra electrical pathway in the heart that begins in the atria. This causes a very fast, steady heartbeat.
  • Atrioventricular nodal reentrant tachycardia (AVNRT), the second most comman type of SVT, occurs when there is an extra electrical pathway in the AV node.
  • Atrial tachycardia is an abnormal rhythm that arises in the atria.
  • Wolff-Parkinson-White syndrome is an abnormal electrical connection between the atria and ventricles. This pathway is known as an accessory pathway and may result in a very rapid heartbeat.

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Supraventricular Tachycardia may cause the following symptoms:

  • Chest pressure or pain
  • Fainting, also known as syncope, or near-syncope
  • Fatigue
  • Lightheadedness or dizziness
  • Palpitations, which can be skipping, fluttering or pounding in the chest
  • Shortness of breath

Supraventricular tachycardia may occur spontaneously with unpredictable timing. Therefore, in many cases, the condition requires specialized tests to acquire an accurate diagnosis. If your doctor suspects that your child has an arrhythmia, one or more of the following diagnostic tests will be ordered to determine the source of your child's symptoms.

  • Electrocardiogram (ECG or EKG) — An ECG records the heart's electrical activity. Small patches called electrodes are placed on your child's chest, arms and legs, and are connected by wires to the ECG machine. The electrical impulses of your child's heart are translated into a graph or chart, enabling doctors to determine the pattern of electrical current flow in the heart and to diagnose arrhythmias.
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The treatment for your child's supraventricular tachycardia (SVT) will depend on the type and severity of their condition and the results of various diagnostic tests, such as the electrophysiology (EP) study. You and your doctor will decide which treatment is right for your child.

The following treatments may be considered:


Certain anti-arrhythmic drugs change the electrical signals in the heart and help prevent heart abnormalities from starting irregular or rapid heart rhythms. Medication may be used to convert SVT to a normal rhythm, slow down the heart rate or prevent recurrences. Our goal is to find the medication that works best for your child. On occasion, we admit children to the hospital and monitor their heart rhythm while we start the medication.

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Reviewed by health care specialists at UCSF Benioff Children's Hospital.

Related Information

UCSF Clinics & Centers

Heart Center

Arrhythmia Center
1825 Fourth St., Sixth Floor
San Francisco, CA 94158
Phone: (415) 514-2783
Fax: (415) 353-4144
Appointment information

Pediatric Heart Center Clinic at Mission Bay
1825 Fourth St., Sixth Floor
San Francisco, CA 94158
Phone: (415) 353-2008
Fax: (415) 353-4144
Appointment information

Cardiac Intensive Care Unit
1975 Fourth St., Fourth Floor
San Francisco, CA 94158
Phone: (415) 353-1955
Fax: (415) 353-9144