Development and validation of diagnostic criteria for atrial flutter on the surface electrocardiogram

There are no universally accepted ECG diagnostic criteria for atrial flutter (AFL), making its differentiation from "coarse" atrial fibrillation (AF) difficult.

To develop diagnostic criteria for AFL, we examined two sets of ECGs. Set 1 consisted of 100 ECGs (50 AF, AFL) with diagnoses confirmed by intracardiac recordings. Criteria evaluated were presence of F waves in the frontal plane leads, F waves in V(1), sawtooth F waves, rate, and regularity of ventricular response. Set 2 included 200 ECGs taken from the hospital database each of which had already been interpreted by a cardiologist as either AF (n = 100) or AFL (n = 100). Set 2 was blindly read by electrophysiologists whose consensus-diagnoses were compared to the diagnoses made by using the best criteria identified from the Set 1 data.

The criteria of frontal plane F waves, regular or partially regular ventricular response, and their combination had sensitivities of 92%, 98%, and 90% and specificities of 100%, 78%, and 100% in Set 1 for the diagnosis of AFL. In Set 2, concordance of electrophysiologist and cardiologist diagnoses was only 84%. The criteria of frontal plane Fwaves, regular or partially regular ventricular response, and their combination resulted in concordances with the cardiologist diagnoses of 85%, 85%, and 82% and with the electrophysiologist-consensus diagnoses of 90%, 89%, and 94% (P < 0.001).

The criteria of frontal plane F waves and regular or partially regular ventricular response aid in the proper diagnosis of AFL. Because management strategies may differ for AF and AFL, it is important to adopt a more rigorous diagnostic approach.