Supraventricular Tachycardia

The heart has 4 chambers (spaces that hold blood): 2 atria at the top and 2 ventricles at the bottom. A complex electrical system makes these chambers squeeze and relax, at the right time and in the right order, to pump blood. A heartbeat starts in the right atrium when a group of cells (sinus node) sends an electrical signal.

In SVT, an overly fast heartbeat comes from a faster-beating (electrically overactive) area of the atria or from a “short circuit” of electricity involving the atria.

SVT typically happens in distinct episodes. How often these episodes happen and how long they last are different from one person to another. Short episodes usually do not bother the person much. But if the fast heartbeat continues too long, the heart can become tired, which can be dangerous.

• Seattle Children’s team of 40+ pediatric cardiologists diagnoses and treats SVT in children of all ages, from newborns to adolescents.
• Our Arrhythmia Program includes 3 full-time pediatric electrophysiologists, more than anywhere else in the region. After their training in pediatric cardiology, they have further subspecialty training in dealing with cardiac arrhythmias, like SVT. The Arrhythmia Program is also supported by a team of specialty technicians and nurses who know how to deal with these conditions.
• We offer a full range of diagnostic procedures and treatments. Along with using heart medicines, we have deep experience with radiofrequency ablation and cryoablation procedures in children who need them to correct an abnormal heart rhythm.

• See our statistics and outcomes.

• If your developing baby is diagnosed with SVT before birth, our Fetal Care and Treatment Center team works closely with you and your family to plan and prepare for the care your baby will need.
• Your child’s treatment plan is custom-made for them. Some children with SVT do not need treatment, and others do. We closely watch your child’s needs to make sure they get the care that is right for them at every age.
• If your child was born with SVT, we have a special Adult Congenital Heart Disease Program to meet your child’s long-term healthcare needs. This program, shared with the University of Washington, transitions your child to adult care when they are ready.

• We are committed to your child’s overall health and well-being and to helping your child live a full and active life.
• Whatever types of care your child needs, we will help your family through this experience. We will discuss your child’s condition and treatment options in ways you understand and involve you in every decision.
• Our nurses are experienced at supporting families with SVT. They help manage your child’s care and teach you and your child about this condition.
• Our child life specialists know how to help children understand their illnesses and treatments in ways that make sense for their age.
• Seattle Children’s has many resources, from financial to spiritual, to support your child and your family and make the journey as smooth as possible. We regularly see families who travel from other states and countries to come to our Arrhythmia Program.
• Read more about the supportive care we offer.

• Doctors at Seattle Children’s are working to advance treatment for SVT and enhance the quality of life for children with this condition.
• We were the first institution in the region to routinely offer cryoablation for children, greatly increasing the safety of ablation for SVT.
• Seattle Children’s is one of the few institutions in the region to offer “zero fluoro” or “minimal fluoro” ablation. This means we use techniques – many that we developed – to expose your child to little or no X-ray radiation. Most places use fluoroscopy during ablation.
• Dr. Stephen Seslar has been part of creating international databases to track information about SVT ablation procedures. These databases help doctors learn more about which methods work best.
• Dr. Terrence Chun has a special interest in developing techniques to improve the safety and accuracy of ablation procedures. He has been invited to lecture on unique aspects of SVT ablation in children.