Handy Tips For Spotting A.Flutter:
#Rapid Recognition
Narrow complex tachycardia at 150 bpm (range 130-170)? Yes -> Suspect flutter!
Turn the ECG upside down and scrutinise the inferior leads (II, III + aVF) for flutter waves.
#Vagal Manoeuvres +/- Adenosine
Atrial flutter will not usually cardiovert with these techniques (unlike AVNRT), although typically there will be a transient period of increased AV block during which flutter waves may be unmasked.
#RR intervals
In atrial flutter with variable block the R-R intervals will be multiples of the P-P interval — e.g. assuming an atrial rate of 300bpm (P-P interval of 200 ms), the R-R interval would be 400 ms with 2:1 block, 600 ms with 3:1 block, and 800 ms with 4:1 block.
Look for identical R-R intervals occurring sporadically along the rhythm strip; then look to see whether there is a mathematical relationship between the various R-R intervals on the ECG.
In contrast, atrial fibrillation will be completely irregular, with no patterns to be discerned within the R-R intervals.
