Atrial Flutter ECG Interpretation #312


  • Atrial Flutter (sometimes called a flutter) occurs when there is an obstruction within the atrial electrical conduction system.
  • Due to this impediment a series of rapid depolarizations occur.
  • These depolarizations may occur two, three, four or more times per QRS complex.
  • The AV node functions like a “gatekeeper” blocking the extra impulses until the ventricular conduction system is able to accept the impulse.
  • The impulse that is accepted will cause the QRS complex to occur.


atrial flutter tracing
  • Each atrial flutter ECG wave represents atrial depolarization. This will be noted next to the P wave step in rhythm analysis. Instead of P waves, this tracing has “F” waves. No P waves mean there is no PR interval measurement.
  • When the tracing is interpreted, the ratio of F waves to each QRS complex will be documented along with the rhythm i.e. Atrial Flutter 4:1 (indicates 4 “F” waves to each QRS complex). Not all Atrial Flutter rhythm strips will have a regular rhythm. In that case just document and report your observations.

Practice Strip

atrial flutter rhythm strip
  • Analyze this tracing using the five steps of rhythm analysis.
  • Compare your answers with the answers on the next slide.

Practice Strip Answers

atrial flutter ECG strip
  • Rhythm: Regular
  • Rate: Ventricles - 80, Atria - 320
  • P wave: "F" waves
  • PR interval: absent
  • QRS: 0.08
  • Interpretation: Atrial Flutter 4:1

Authors and Sources

Authors and Reviewers


? v:3 | onAr:0 | onPs:2 | tLb:0 | pv:1
uStat: False | db:0 | cc: | tar: False
| cDbLookup # 0 | pu: False | pl: System.Collections.Generic.List`1[System.String]

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