Supraventricular Tachycardia (SVT)

The sinus node (sinoatrial node or SA node) is the heart's own pacemaker. The electrical impulse is normally initiated here. The impulse travels across the atria (top 2 collecting chambers) stimulating contraction or "squeeze" and will eventually push blood into the ventricles (the bottom 2 pumping chambers).

The impulse then reaches the AV node (atrioventricular node). This is referred to as the "gateway" to the ventricles. The AV node receives the impulse from the SA node.

The impulse moves through special electrical tissue starting at the Bundle of His, moving to the bundle branches. This stimulates ventricular squeeze, which pumps blood to the lungs and the rest of the body. Each of these cycles is a "heart beat". Below is a picture of cardiac conduction system.

Normal heart rate varies in children based on age. Infants and children have a faster heart rate compared to adults. The normal adult heart rate is 60-100 beats per minute.

What are the symptoms?

  • Palpitations- the feeling of a rapid or erratic heart beat while sitting quietly or at rest or faster than normal heart rate with exercise
  • Dizziness
  • Fainting (syncope)
  • Chest pain
  • Shortness of breath
  • Heart pounding
  • Feeling pulsations in your throat
  • Sudden sense of a fast heart rate and a sudden end to the to the fast heart rate
  • Toddlers and younger (when verbal) children may describe symptoms as their “heart beeping”

Infants cannot communicate their symptoms but they may exhibit signs of:

  • Poor feeding
  • Profuse sweating with feeding
  • Being Listless/lethargic
  • Appearing generally ill
  • Breathing faster than normal

These symptoms can be brief but can also last for several hours.

Your EP team may prescribe medication for treatment. Medication is not a cure but can decrease the number of episodes and help to control symptoms.  In most cases, these medications are taken daily.