Overview
- Tachyarrhythmia at the slow end of flutter/fibrillation spectrum; produced by macro-reentry within a single circuit in atria; characterized by regular uniform F waves
- Organized macro-reentrant electrical activity in the atrium resulting in rapid, regular flutter (“F”) waves
ECG Features
- Flutter wave rate: 214-340 beats/min (often 240-340 beats/min)
- Ventricular rate can be irregular with coexisting variable AV block
- “Fixed” = constant RR intervals; “variable” = irregular RR intervals
- Typical (common) atrial flutter: sawtooth pattern with inverted flutter waves in lead II, III, and aVF + positive flutter waves in lead V1; due to counterclockwise reentry around the tricuspid annulus
- Atypical (uncommon) atrial flutter: sawtooth pattern with inverted flutter waves in V1 + positive flutter waves in leads II, III, and aVF (i.e. opposite pattern of typical); due to clockwise reentry in the right or left atria; may occur after ablation or following congenital/valvular cardiac surgery
- Management: similar to atrial fibrillation (e.g. catheter ablation, antiarrhythmic agents, cardioversion), although rhythm control strategy is favored because rate control can be difficult to achieve and often requires high doses of >1 AV-nodal blocking agent; definitive treatment for typical atrial flutter = catheter ablation (high success [>95%] and low complication rates); oral anticoagulation approach is similar to atrial fibrillation; high risk of recurrent atrial flutter with antiarrhythmic therapy
