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Assoc Prof Harry Mond
December 2, 2024
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I often see ECGs on topics I have previously covered and would love to share them with you. This diagnosis was a first for me:
I gave it a name and then checked the literature and it has been reported.There is a ventricular ectopic every 5th beat; ventricular pentageminy. To summarize:
This is something I rarely see on Holter monitors but is well known to those who ablate atrial fibrillation triggers in the pulmonary veins. This is seen post-procedure.
The top illustration shows atrial fibrillation with a controlled ventricular response. Below are short fragmented episodes of pulmonary vein firing (red highlight) which cause sinus reset but fail to initiate sustained atrial fibrillation. Effectively, the runs are “trapped” in the pulmonary vein at the junction with the left atrium and cannot conduct. The bradycardia probably reflects high vagal tone.
Note there is also atrial bigeminy (yellow highlight).I have previously shown a similar appearance, where the atrial activity was not fragmented.
This is non-conducted focal atrial tachycardia with sinus reset and Wenckebach block at the ectopic myocardial junction.Finally this one shows a ventricular couplet (red highlight) and what appears to be an atrial triplet (yellow highlight) in sequence.
The sinus P waves are the red arrows with two being concealed (red stippled and blue). The blue one, however, probably conducts to the ventricle with a very long PR interval which then allows retrograde conduction to the atrium (black arrows) setting up a re-entry circuit. Therefore, not a triplet as one is sinus.Any better suggestions? Remember, it’s all in the timing.
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Harry Mond
October 29, 2026
As its name implies, AVNRT is a reentrant junctional or supraventricular tachyarrhythmia which involves the fast and slow pathways within the AV node creating a self-perpetuating circus movement. It can be divided into typical (slow-fast) or atypical (fast-slow) as well as several rarer forms related to more than one slow or fast pathway with similar electrophysiological properties. On the ECG, they can be identified and differentiated by the positioning of the P wave in relation to the QRS complex, which in turn is related to the direction of the re-entrant AV nodal circuit. However, in about 60% of cases, the P wave is buried in the QRS/T and cannot be identified on the surface ECG.
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
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