WHAT IS ATRIAL FLUTTER ECG

What is Atrial Flutter

Atrial flutter (AFL) is a common abnormal heart rhythm that starts in the atrial chambers of the heart. When it first occurs, it is usually associated with a fast heart rate and is classified as a type of supra ventricular tachycardia.

Atrial flutter is characterized by a sudden-onset (usually) regular abnormal heart rhythm on an electrocardiogram (ECG) in which the heart rate is fast. Symptoms may include a feeling of the heart beating too fast, too hard, or skipping beats, chest discomfort, difficulty breathing, a feeling as if one’s stomach has dropped, a feeling of being light-headed, or loss of consciousness.

Atrial Flutter ECG:

The Atrial Flutter ECG shows regular flutter waves F-waves ; not to be confused with f-waves seen in atrial fibrillation which gives the baseline a saw-tooth appearance. Atrial flutter is the only diagnosis causing this baseline appearance, which is why it must be recognized on the ECG. The flutter waves (on the contrary to f-waves in atrial fibrillation) have identical morphology (in each ECG lead).

Flutter waves are typically best seen in leads II, III aVF, V1, V2 and V3. The exact appearance of the flutter waves will depend on the location and direction of the re-entry circuit. In the most common type of atrial flutter, the re-entry loops around the tricuspid valve in a counter-clockwise direction. This yields negative flutter waves in II, III and aVF and positive flutter waves in V1.

If the re-entry has a clockwise direction, the flutter waves are positive in lead II, III, aVF and the P-waves typically have a notch on the apex. Please note that for most clinicians it is not necessary to be able to determine the direction of the re-entry loop.

Regularity of the QRS

The regularity of the QRS complexes frequently present with atrial flutter helps to distinguish it from atrial fibrillation, though atrial flutter with variable conduction of the P waves can also occur. In this situation, there may be three P waves to one QRS complex, then a quick change to two P waves to one QRS complex, and so on; any combination of P waves to QRS complexes can occur. This results in the rhythm becoming “irregularly irregular.”

There are only two other rhythms that are commonly irregularly irregular, including atrial fibrillation and multifocal atrial tachycardia, or MAT.

When the heart rate is significantly elevated — that is, greater than 150 bpm — it is often difficult to determine atrial flutter from atrial fibrillation, atrial tachycardia or atrioventricular nodal reentrant tachycardia, or AVNRT. In this situation, giving adenosine will transiently slow the ventricular rate, unmasking the atrial flutter waves and allowing a more definitive diagnosis to be made.

Atrial flutter can described as “typical” (type I) or “atypical” (type II) based on the anatomic location from which it originates. Also, atrial flutter can be described as “clockwise” or “counterclockwise” depending on the direction of the circuit.

Typical atrial flutter

Typical atrial flutter rotates counterclockwise in direction, from a reentrant circuit around the bicuspid valve annulus and through the cavo-tricuspid isthmus. This results in negatively-directed flutter waves in the inferior leads.
At times, the direction of the circuit can reverse, causing clockwise atrial flutter from the same anatomical location.

This appears as positively-directed flutter waves in the inferior leads. Atypical atrial flutter originates from the left atrium or areas in the right atrium, such as surgical scars, and has a variable appearance on ECG in regards to the flutter waves.

If you are facing abnormal heart rhythm which also say Atrial Flutter, Consultant with best cardiologist near you. Dr Boon Lim is also best heart rhythm specialist in London, you can consult with him.