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ECG library

High-grade AV block

advanced

An 84-year-old with presyncope on the stairs; a strip full of unconducted P waves.

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

  • Two or more consecutive dropped beats
  • Constant PR on conducted beats
  • Slow ventricular rate

Learning points

  • High-grade block sits between Mobitz II and complete block and shares their pacemaker indication.
  • Atropine rarely helps infranodal disease; pacing pads on early.

Connected