This week, I saw two similar unusual ECG appearances on consecutive days.
Is this artefact?
What do you think?
The pauses are real and there is a non-conducted atrial tachyarrhythmia, which terminates abruptly after a few beats.
I see similar appearances about once a month, so it is not rare.
I will show a few more examples:
Because it doesn’t conduct, the asystolic pauses can be quite long and symptomatic.
Why then, does the tachyarrhythmia stop abruptly?
Clue: Remember, my obsession with Wenckebach.
Some of you will say that is the reason…… and you would be correct!!!!!
This is one of the non-atrioventricular Wenckebach blocks.
Focal atrial tachycardia with Wenckebach block at the ectopic-myocardial junction.
The footprint is the same as with sino-atrial Wenckebach (fun with ECGs 21):
The P to P cycle length shortens until there is block (red highlight).
Can it occur in the ventricle? Of course!
A fast-short run of a tachyarrhythmia, with the last cycle length, being the shortest.
If you look you will find it!
Remember it’s all in the timing.
In 49+ years as a practicing cardiologist, Dr Harry Mond has published 260+ published manuscripts & books. A co-founder of CardioScan, he remains Medical Director and oversees 500K+ heart studies each year.
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