EKG

Atrial Flutter

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Atrial Flutter, Flutter Wave, F Wave

  • See Also
  1. Atrial Fibrillation
  2. Atrial Fibrillation Causes
  3. Electrocardiogram in Atrial Fibrillation
  4. Atrial Fibrillation Acute Management
  5. Atrial Fibrillation Anticoagulation
  6. Atrial Fibrillation Cardioversion
  7. Atrial Fibrillation Rate Control
  • Pathophysiology
  1. Right atrial reentry circuit around the tricuspid ring
  2. Macro-reentry Tachycardia
    1. Reentry around the entire atrium
    2. Contrast with micro reentry circuits around smaller regions (e.g. AV Node)
  • Types
  1. Type I Atrial Flutter (typical)
    1. Constant atrial rate of 240 to 350 beats per minute
    2. Natural rate is altered by age, atrial dilation and Antiarrhythmics (esp. Type Ia or Type Ic)
    3. Ventricular rate will usually be at least a 2:1 block (or 3:1 or 4:1)
      1. AV Node prevents rates above 180
  2. Type II
    1. Constant atrial rate at 340 to 440 beats per minute (Faster Atrial Flutter rate than with Type I)
    2. Differs from Type I in reentry accessory path
  • Signs
  1. Constant atrial rate
    1. Atrial to ventricular rates may range from 1:1 to 4:1
    2. Atrial to ventricular rate 2 to 1 (most common)
      1. Atrial rate of 240 to 350 beats per minute
      2. Ventricular rate 140-150 beats per minute
  • Differential Diagnosis
  1. Atrial Fibrillation
    1. Irregular rhythm without Flutter Waves
    2. Patient may fluctuate between Atrial Fibrillation and Atrial Flutter on the same EKG
  2. Sinus Rhythm
    1. Flutter Wave may be difficult to identify in 2:1 block, and regular rhythm at 150 bpm may be mistaken for NSR
      1. Atrial Flutter is typically obvious with 3:1 or 4:1 blocks in which the Flutter Waves are easily identified
    2. However, sinus rhythm responds to specific management for cause (e.g. IV fluids in Dehydration)
      1. Atrial Flutter, in contrast will maintain a contant ventricular rate
  • Diagnostics
  • EKG
  1. Constant atrial rate
    1. Atrial rate: 300 per minute (typical)
    2. Atrial to ventricular rate
      1. Ratio 1:1 - 300 bpm (Rare, but potentially lethal)
      2. Ratio 2:1 - 150 bpm (most common)
      3. Ratio 3:1 - 100 bpm
      4. Ratio 4:1 - 75 bpm
  2. Saw tooth Flutter Waves (F Wave)
    1. Flutter Waves are best seen in the inferior leads
    2. May be difficult to visualize at a 2:1 AV Block (rate 140-150) due to overlapping QRS Complex with Flutter Wave
    3. Increase EKG "paper speed" to 50 mm/sec (rapid) to spread out complexes (P Waves may be seen)
  3. Images
    1. cvEKGAtrialFlutter4to1SawTooth.jpg
  • Management
  1. See Atrial Fibrillation Management
  2. Highly responsive to Synchronized Cardioversion at low energy levels
    1. Dr. Amal Mattu (paraphrased): "you could rub your shoes on the carpet to shock Atrial Flutter back to sinus"
    2. However Atrial Flutter is often resistant to rate control agents (Metoprolol, Diltiazem)
  • References
  1. Berberian (2023) Crit Dec Emerg Med 37(3): 14-5