Overview

<aside> 💡 It is a form of SVT characterised by a a succession of rapid atrial depolarisation waves.

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• Normally the electrical signals pass through the atria once
• This stimulates a contraction then disappears through the AV node into the ventricles.
• Atrial flutter is caused by a “re-entrant rhythm” in either atrium
• The electrical signal re-circulates in a self-perpetuating loop due to an extra electrical pathway.
  • The signal goes round and round the atrium without interruption
• This stimulates atrial contraction at 300 bpm
• The signal goes round and round the atrium without interruption

Associated conditions

• HTN
• IHD
• Cardiomyopathy
• Thyrotoxicosis

ECG changes

• Sawtooth appearance
• As the underlying atrial rate is often around 300/min the ventricular or heart rate is dependent on the degree of AV block.
  • For example if there is 2:1 block the ventricular rate will be 150/min
• Flutter waves may be visible following carotid sinus massage or adenosine

Management