Since atrial flutter is due to a macro re-entry, it is the arrhythmia which is most sensitive to cardioversion at low energies.

Hence a narrow QRS tachycardia with a rate of 150/min, which appears to be SVT is likely to be atrial flutter with 2:1 conduction.Ĭlose scrutiny of the baseline for saw-tooth like flutter waves, especially in the inferior leads is needed to exclude atrial flutter. A typical situation of atrial flutter is with 2:1 conduction, atrial rate of 300/min and ventricular rate of 150/min. If there is 1:1 conduction, the ventricular rates will be very high. If the waves are positive in inferior leads, it is clockwise loop and if negative, the re-entry loop is counter-clockwise.Ītrial flutter is usually associated with a fixed ratio AV block. The direction of the less sharp component of the flutter wave is taken as the direction of the wave. Isthmus dependent flutter can be typical and reverse typical depending on whether the re-entry is counter-clockwise or clockwise. Non isthmus dependent flutters are the scar related flutters and caval mediated flutters. In the left atrium there is mitral isthmus. In the right atrium it is the cavotricuspid isthmus. Atrial flutter can be classified into isthmus dependent and non-isthmus dependent. 3 rd Ed.Atrial flutter is an organized atrial tachyarrhythmia due to macro re-entry typically with saw tooth shaped flutter waves in the ECG. Topol, E., Califf, R., Prystowsky, E., Thomas, J., Thompson., (2007) Textbook of Cardiovascular Medicine. This is less successful in type 2 flutter cases.The aim when treating atrial flutter is to return the patient’s rhythm to one of a sinus nature. Varying degrees of block can appear on one recording i.e 2:1 and 3:1. Ensure to scrutinise the trace so as not to confuse flutter with fibrillation. The fixed AV block ratio, 2:1, 4:1, etc may not always present. The QRS presentation will normally be a narrow complex and areas of the trace will have no isoelectric baseline. Type 2 atrial flutter is less common and atrial rate can reach up to 450bpm. In essence, a 2:1 block implies that the ventricular rate is half that of the atrial rate, so a 4:1 rate would be a quarter.Īnti-clockwise re-entry atrial flutter accounts for around 90% of presentations and exhibits:Ĭlockwise re-entry flutter is less common, and produces: These degrees of AV block are referred to by way of a ratio of P waves and QRS complexes, the most common being 2:1 or 4:1. The rate at which the ventricles contract is dictated by the eventual atrioventricular node conduction. P waves are still present on the patient ECG, but will display a “saw-tooth” pattern know as F waves.

The size of the right atrium directly corresponds to the length of the re-entry pathway, and the resulting atrial rate is somewhere between 200-400bpm, but most commonly 300. This pathway can be the result of scarring after surgery or idiopathic, so of unknown origin.

In cases of atrial flutter, the normal conduction pathway of the heart from the Sinoatrial node, through the atrioventricular node to the ventricles, is interrupted causing a re-entry pathway. Atrial flutter is a supraventricular tachycardic arrhythmia that tends to occur in individuals of an advanced age, although it is linked to endurance sports, also.

A flutter ekg