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ECG library

Sinus bradycardia

intro

A 24-year-old rower at a pre-participation physical. Asymptomatic.

25 mm/s · 10 mm/mV · synthetic tracing
100%
IIIIIIaVRaVLaVFV1V2V3V4V5V6
II (rhythm)
Calipers:2000 ms50.0 small boxes30 bpm if R-RDrag the orange markers. One small box = 40 ms.

Key findings

  • Rate below 60 with normal P-QRS relationship
  • Every interval proportionally relaxed

Learning points

  • The question is never the number alone: symptoms, medications (beta blockade), and conditioning decide its meaning.
  • Nocturnal rates in the 30s are common in the young and fit.

Connected