Code 3 Workshop

Paramedic Education
Home/All lessons/Cardiac & ECG/Pediatric SVT vs Sinus Tachycardia
Lesson

Pediatric SVT vs Sinus Tachycardia

11 min Cardiac & ECG Skip to quiz

Objective: Tell pediatric SVT apart from sinus tachycardia by P waves, a rate that changes, and a reason for the rate. Treat the cause or the rate. Do not copy an adult number.

Why this matters

Do not call every fast narrow complex SVT. SVT means supraventricular tachycardia. In children this is easy to get wrong. A sinus rate that would be SVT in a 40-year-old can be normal in a febrile infant. Rough cutoffs still help. SVT is often about 220 or faster in infants and about 180 or faster in children. Use the tracing and the story with the number. Do not copy an adult cutoff.

Sinus tachycardia has P waves, changes when you stimulate the child, and has a reason. The reason may be fever, pain, dehydration, hypoxia, or shock. SVT is usually sudden and regular, with no visible P wave or a retrograde P wave, and the child looks worse than the fever explains. Adenosine in sinus tachycardia from sepsis does not fix the cause. It delays the real work.

Clinical sequence

  1. Protect the airway, breathing, and circulation first. Give oxygen if the sat is low. A hypoxic child with a fast rate is a breathing problem first.
  2. Print or freeze a strip. Name the rate, whether it is regular, whether there are P waves, whether the rate changes, and the story. If the rate changes when they cry, that points to sinus tachycardia. Check glucose if they are not acting normally.
  3. Look for a reason: fever, fluids, work of breathing, blood loss, or pain. A reason plus P waves is sinus tachycardia until you prove otherwise. Treat the cause. Do not chase the number with adenosine.
  4. If it is SVT and they are unstable from the rate, put the pads on and use synchronized cardioversion per protocol. Unstable means shock, altered mental status, or collapse, not a high number alone. Do not debate an adenosine dose first. If they are stable, use a vagal maneuver and then adenosine only if your protocol says so. Ice to the face is a vagal tool some systems use for infants. Protocol owns that step. Then reassess.

Teaching points

  • Rate cutoffs are education, not a law. Overlap exists. The tracing and perfusion decide.
  • Sinus tachycardia: a P wave comes before every QRS, the rate changes with stimulation, and there is a physiologic reason. Treat the reason.
  • SVT: it starts suddenly, it is very regular, P waves are absent or retrograde, and the rate stays stuck. The history is often that it just started.
  • Unstable means poor perfusion, not a number. Look for poor tone, mottled skin, delayed capillary refill, altered mental status, or hypotension for age. Use electricity per protocol.
  • Do not give adenosine for compensatory sinus tachycardia. A brief pause will not fix septic shock.
Verbalize
  • I am asking three things. Are there P waves? Does the rate change? Is there a reason?
  • About 220 in an infant, or 180 in a child, is a clue. It is not a verdict.
  • If they are unstable from the rate, I am using electricity.
  • If it is sinus tachycardia, I am treating the cause.

Common errors

  • Giving adenosine to a febrile toddler at 190 with visible P waves.
  • Calling 210 in a crying infant “definitely SVT” without a strip.
  • Delaying cardioversion in a gray, unresponsive child with SVT to try drugs first.
  • Missing hypoxia as the reason for the rate.

Practice

One-minute check

Partner: a 4-month-old, rate 270, gray, barely crying, and no P waves. Then a 4-month-old, rate 180, hot, dry, with P waves, and crying hard. Name the path for each in one sentence.

Related: SVT: Adenosine Framing, Stable vs Unstable Tachycardia, Synchronized Cardioversion.

Sources & Further Study

Named guidelines for further study. They are not clinical orders and do not replace your protocol or medical direction.

Education only. Apply learning within your protocols and medical direction. This is not clinical care guidance.

Check Your Understanding

Questions drawn only from this lesson. After you check, the key is highlighted. Education practice — not a certification exam.

1. A febrile, dry infant at 180 with P waves and a rate that rises when they cry is most often:
2. An infant rate of 270 with no P waves is treated as:
3. Adenosine in compensatory sinus tach from dehydration:
4. A gray, unresponsive child whose rate is 280 and regular should get:
← STEMI Mimics in the Field Lead Misplacement and Artifact →