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Assoc Prof Harry Mond
February 23, 2026
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In the previous ECG presentation, we learnt how to recognise reversed arm leads. Here is a summary:
Lead I is flipped and leads aVR and aVL are reversed. This same scenario occurs with dextrocardia, where the leads are not reversed, but rather the heart is positioned with the apex of the left ventricle on the right side.
‍Here is an ECG from a patient with dextrocardia:
With dextrocardia the chest leads are very different.
Leads V1 and V2 are reversed and leads V3 to V6 appear as they would, if the leads were placed on the right side (V3R to V6R) in a normal patient.
Here is another example of dextrocardia:
Now let us change the arm leads (no need to swap the leg leads) and place the chest leads on the right.
Presto; We have a near-normal looking ECG.
I have seen an inexperienced technician place the leads on the right side of the chest, but the limb leads normal!
The ECG reporter can often get confused, when the chest leads are inadvertently reversed, but on the left side of the chest. I have seen this reported as dextrocardia.
Here is an example:
Finally, the pièce de résistance!
I call this the “full hand” and I have seen it several times. There are reversed arm and chest (on the left side) leads. Remember, keep your eyes open when reporting ECGs!
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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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