Atrial Flutter

Atrial re-entrant arrhythmia where the electrical impulse circles within the atria. The:

Atrial rate is usually ~300
Ventricular rate is function of AV nodal conduction and occurs as a ratio of the atrial rate
- Usually 2:1, i.e. ventricular rate ~150
- 1:1 is rare and potentially lethal
- Ratio is usually fixed, so the ventricular rate is usually abnormally constant
  Note the ratio may vary (e.g. between 2:1 and 3:1).
Pathway may be either:
- Typical
  - Counter-clockwise circuit between the tricuspid orifice, vena cavae orifice, and crista terminalis
  - 90% of cases
  - Sawtooth appearance best seen in V₁, with a negative defelction in the inferior leads
- Non-typical
  - Clockwise circuit
  - Usually associated with atrial disease
    Scar, structures.

Epidemiology and Risk Factors

Drug therapy for flutter is notoriously unsuccessful and electrical cardioversion is often required.

Specific therapy:

Pharmacological
- Antiarrhythmics
  - Class IA and IC drugs may lead to 1:1 conduction and so this is less preferred.
- Anticoagulation
  As per AF, although there is less data supporting this.
Physical
- Cardioversion
  Synchronised at 50J.
- Rapid atrial pacing
  Must be faster than the atrial flutter rate.
Procedural
- Ablation
  For recurrent flutter. Most effective for typical disease.

Bersten, A. D., & Handy, J. M. (2018). Oh’s Intensive Care Manual. Elsevier Gezondheidszorg.