Atrial Flutter - Typical Atrial Flutter (AFL) - Case Study

Typical Atrial Flutter (AFL) is the most common type of atrial flutter and is a macro-reentrant right atrial tachycardia that uses the cavo-tricuspid isthmus as an essential part of a counter-clockwise circuit. The tendon of Todaro, the crista terminalis, the inferior vena cava, the tricuspid valve annulus, and the coronary sinus os provide anatomical landmarks of the circuit. Typical AFL can be described as having a “sawtooth” appearance from an aVF ECG vector used with the Carnation monitor. AFL can manifest with either a regular or irregular ventricular response depending upon AV node conduction. AFL, when regular in its ventricular response, will manifest fractions of its atrial cycle length. Atrial rates typically range between 220-320 bpm. AFL can have fixed atrial-to-ventricular conduction ratios of 1:1, 2:1, 3:1, 4:1 or, as often occurs, variable AV conduction superficially mimicking AF, albeit with much less randomness than true AF. The key takeaway here is that typical atrial flutter waves will be the same and its ventricular response can be an exact fraction of its atrial cycle or vary.