Skip to main content
ECG library

Atrial flutter with 2:1 conduction

core

A 68-year-old with COPD, 'regular palpitations' at exactly 150.

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

  • A regular narrow tachycardia at almost exactly 150
  • Sawtooth baseline inferiorly

Learning points

  • 150 is the number that should whisper 'flutter with 2:1' every time.
  • Vagal maneuvers or AV nodal blockade unmask the sawtooth by increasing block.

Connected