Assoc Prof Harry Mond
February 23, 2026
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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. In summary:
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).
Another example:
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.
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Harry Mond
October 16, 2026
Retrograde conduction is defined as conduction from an ectopic site to the atrium via the AV node or accessory pathway and referred to as VA conduction. II results in a P wave configuration which differs from an anterograde P wave, and in most ECG leads is inverted. The site from where the impulse originates can be the AV node, Bundle of His, distal conducting system or the body of the ventricles including ventricular pacing. On the ECG, the QRS complex usually precedes the inverted retrograde P wave but on occasion may follow it.
October 1, 2026
In 1970, I commenced work as a “novice” cardiologist at The Royal Melbourne Hospital. Training at that time was learning how to recognise the diastolic murmur of mitral stenosis and making sure the ECG and chest x-rays were the correct way up. As this was prior to coronary artery surgery, stenting and echocardiography, the ECG was a highly respected tool for the diagnosis of many conditions. I was fortunate to befriend a number of the gurus of ECG interpretation who taught me to look into the soul of an ECG. Today, even though the ECG is the first investigation performed by a cardiologist, the art of ECG interpretation has been lost because we depend on the new tools for cardiac diagnosis.Â
September 18, 2026
Dr Thura Thant asked for an opinion on this confusing ECG. By using arrows and highlight, the ECG bared its soul and gave me an answer. ‍See if you can work it out? What do you think?
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