ECG Interpretation for 16-Year-Old Male
These ECG measurements are entirely normal for a 16-year-old male and require no further evaluation.
Analysis of Individual Parameters
PR Interval: 122–135 ms
Both values fall well within the normal range. According to international athlete screening guidelines, first-degree AV block is defined as PR interval 200–400 ms 1. Your measurements are significantly shorter than this threshold. Normal PR intervals in adolescents typically range from 120–200 ms, and values between 122–135 ms represent completely physiologic conduction 2, 3.
QRS Duration: 67 ms
This is normal and narrow. Abnormal QRS prolongation requiring evaluation is defined as:
At 67 ms, this QRS duration is well within the expected range for a 16-year-old male 2, 3, 4.
QTc: 414–427 ms
Both corrected QT values are clearly normal. The guideline threshold for abnormal QTc in males is:
- ≥470 ms (abnormal requiring evaluation) 1
- ≥500 ms (marked prolongation)
Your values of 414–427 ms are more than 40 ms below the abnormal threshold, placing them comfortably in the normal range 2, 5.
Heart Rate: 64 bpm
This is normal. Sinus bradycardia in athletes is defined as ≥30 bpm and is considered physiologic 1. Profound bradycardia requiring evaluation is <30 bpm or sinus pauses ≥3 seconds 1. A heart rate of 64 bpm is entirely appropriate for a 16-year-old, whether athletic or sedentary 3, 4.
Age-Specific Considerations
At 16 years old, this patient is at the transition point where ECG patterns become similar to adult norms 6. The so-called "juvenile ECG pattern" (T-wave inversion in V1–V3) is considered normal in athletes <16 years but becomes rare after age 16 1. However, none of the measurements provided suggest any juvenile or pathologic patterns.
Clinical Recommendation
No further cardiac evaluation is indicated based on these ECG measurements alone, assuming:
- The patient is asymptomatic
- No family history of sudden cardiac death or inherited cardiac disease
- No other abnormal ECG findings (T-wave inversions, ST-segment changes, pathologic Q waves, etc.)
All four parameters fall well within established normal ranges for this age group, with substantial margins of safety from any pathologic thresholds 1, 2, 3.