In a 16‑year‑old male with a PR interval of 122 ms, is this considered normal and does it require any specific management?

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Last updated: September 18, 2026 • View editorial policy

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PR Interval of 122 ms in a 16-Year-Old Male: Normal Finding

A PR interval of 122 ms in a 16-year-old male is completely normal and requires no further evaluation or management. This falls well within the normal physiologic range for this age group.

Normal PR Interval Parameters

The normal PR interval in adults and adolescents ranges from 120-200 ms 1. According to international guidelines for ECG interpretation in athletes, first-degree AV block is defined as a PR interval of 200-400 ms 1. Your patient's PR interval of 122 ms is:

  • Just above the lower limit of normal (120 ms)
  • Well below any threshold for first-degree AV block (≥200 ms)
  • Within the expected physiologic range for a healthy adolescent

Clinical Significance

Recent research demonstrates that isolated short PR intervals in pediatric and adolescent athletes are benign age-dependent variants. A 2026 study of 1,310 young athletes (ages 7-18) found that 26.9% had PR intervals <120 ms, with no significant associations between short PR interval and cardiac symptoms, syncope, palpitations, chest pain, or exercise-induced arrhythmias 2.

Key Points:

  • No symptoms = no concern: In asymptomatic individuals, PR intervals in this range do not predict adverse outcomes
  • Age consideration: By age 16, ECG patterns typically resemble adult patterns, making interpretation more straightforward 3
  • Athletic context: If this patient is an athlete, even more pronounced ECG variations (including PR intervals of 200-400 ms) are considered normal training-related adaptations 1

When to Be Concerned

A PR interval would be considered abnormal only if:

  • <120 ms with delta wave and wide QRS (≥120 ms): This defines ventricular pre-excitation (Wolff-Parkinson-White pattern) and requires further evaluation 1
  • ≥400 ms: Defined as "profound first-degree AV block" requiring investigation 1

Important Caveat:

The presence of a delta wave (slurred upstroke in QRS complex) is the critical distinguishing feature. Without a delta wave and wide QRS, a PR interval of 122 ms is simply a normal variant, not pre-excitation 1.

Management Recommendation

No action required. This patient needs:

  • No additional testing
  • No follow-up ECGs specifically for the PR interval
  • No activity restrictions
  • Reassurance that this is a normal finding

The PR interval of 122 ms represents normal atrioventricular conduction and should not trigger any diagnostic cascade or concern about future cardiac events.

References

1
Guideline

international recommendations for electrocardiographic interpretation in athletes.

Journal of the American College of Cardiology, 2017

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.