Atrial Flutter Vs Atrial Fibrillation Vs Artifacts - Clear Your ECG Concepts

 

Can you diagnose what's going on in this ECG strip?

So before I go into a diagnosis can I ask what's the atrial rate and what is the ventricular rate?

Summary: This is just artifact, as you can see V rate doesnt change ,there is no Apc to trigger a reentrant rhythm like flutter,V rate is not a mutiple of 300 which u would expect if atrial rate was truly 300,termination is without any pause or any suggestion of sinus node overdrive

Of All the atrial arrhythmias, 

To differentiate between Atrial fibrillation (AF) and 

Atrial flutter (AFL)

(typical & atypical) are sometimes technically very challenging esp for the non EP , but it’s very important to be able to identify correctly as each of these has a different management strategy, however sometimes even for EP it is not that easy unless EPS is done! 

Reason of such complexity especially in case of flutters is because of the so many types of atypical flutters, with so many ecg morphologies !!

Any general physician and cardiologist will think of Flutter once the characteristic ‘sawtooth’ pattern flutter waves “F” are seen especially in limb leads II, III, and avF !!! 

For an EP speciality there is however much more needed to be done in not only for the correct labelling but especially if any ablation is to be contemplated ! 

The 12 lead Surface ECG as usual have many diagnostic limitations!  

some of the clues /keys to reach to the correct label can still be the following !!!

1. The basic key to understanding and possible correct identification of the arrhythmia in this case is to only focus on the atrial activity/ deflections and not on ventricular (QRS) rate and rhythm. As An irregular V rhythm may be caused by varying degrees of AV nodal block inc Wenckebach cycles. 

2. classic “F” waves (normally representing the typical AFL), They will almost always have a distinct & measurable & reproducible CL & normally will have the same axis hence so often resembling a sawtooth pattern. 

(This “saw tooth's pattern” is most obvious in the inferior limb leads, with a slow downward slope (CTI) followed by a fast upward slope as the current going up septum and then coming onto the inferior leads through the lateral wall .This saw tooth’s pattern is more easily seeable when the ventricular rate response is controlled). 

3. “atypical” F waves (may represent atypical AFL or May still be a variant of typical AFL or even AF!!) These atypical F waves may look quasi regular (which means seeing to be apparently regular however not regular in reality on measurement) especially in lead V1 !! and can dodge the less knowledgable to label it as AFL , though it can still be an AF !!!(phenomena called regional intra-atrial organisation giving rise to this appearance) . 

4. these waves may be of so very low-amplitude or can have so irregularly irregular R to R interval (most common or fav term of non EP Drs !!) and lead to label of AF though both of these patterns may still occur happen in AFL, especially if it’s atypical!!!

5. Pinpointing the flutter waves becomes even more difficult when A to V conduction is 1:1 or 2:1, as the flutter activity is either wholly or partially hidden within the QRS/T. This becomes even more challenging at times when the flutter waves are of very low amplitude. So Whenever making any assessment of Atrial arrhythmia esp flutter it is always important to review the complete 12-lead ECG.

6. These points above explain why the ECG diagnosis of “AF/AFL” is still a biggest dilemma , not only to Jnr Drs, cardio Drs and to even relatively less experienced EP Drs ! 

How to differentiate Right vs left sided sided atrial flutter

The most useful ecg lead to differentiate right from left AFL is chest lead V1.  

1. A broad-based upright V1 is highly suggestive of a left-sided flutter. 

2. when V1 has an initial isoelectric (or inverted) component (followed by an upright component), this is consistent with a right AFL. 

3. Conversely, when V1 is deeply inverted, this is highly suggestive of a right-sided flutter. 

4. And when V1 is biphasic or isoelectric, it is not helpful in predicting the exact chamber