Classification of Atrial flutter
Commonest form of atrial flutter
[A] Typical atrial flutter with Clockwise Reentry
[B] Typical atrial flutter with Anti-Clockwise Reentry
[C] Atypical atrial flutter
[D] Type II flutter
Classification of Atrial Flutter
Typical atrial flutter
Typical atrial flutter (common) – type I flutter – involves the IVC & tricuspid isthmus in the reentry circuit.
Anticlockwise Reentry: Commonest form of atrial flutter (90% of cases). Retrograde atrial conduction produces:
- Inverted flutter waves in leads II,III, aVF
- Positive flutter waves in V1 — may resemble upright P waves
Clockwise Reentry: This uncommon variant produces the opposite pattern:
- Positive flutter waves in leads II, III, aVF
- Broad, inverted flutter waves in V1
Atypical atrial flutter (uncommon)
- Sometimes referred to as type II flutter, does not fulfill criteria for typical atrial flutter
- Often associated with higher atrial rates and rhythm instability
- Less amenable to treatment with ablation
