Assoc Prof Harry Mond
February 23, 2026
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I was shown this ECG as a good example of dextrocardia.
What do you think?
Dextrocardia has characteristic ECG findings:
Limb leads:Identical to reversed arm leads:
Chest leads: When the chest leads are placed in the traditional manner, leads V1 and V2 are reversed, and the remaining V leads are moving away from the heart with absentR waves and ever decreasing QRS size.
To visualize the normal ECG, the leads should be placed across the right chest as shown.
Here is another example of dextrocardia:
In our ECG, the features of reversed arm leads are present and consistent with dextrocardia.
What about the chest leads?
The chest leads have all been reversed, so that V1 is in the V6 position and V6 is in the V1 position.
So reviewing our ECG:
I call this “The Full Hand” in that both the arm and chest leads are reversed.
Although rare, I find this more common than dextrocardia.
Reversal in only the limb or chest leads is not uncommon.
Limb lead reversal (yellow highlight):
Chest lead reversal (yellow highlight):
I love to finish with a doozy! I reported this as dextrocardia.
I was told the patient’s heart had normal orientation.
I found an ECG done a year before:
This is :
I suspect the person recording the ECG saw poor progression of R waves across the chest leads and mistook this for possible dextrocardia, hence reversing the arm leads and chest leads to the right.
October 28, 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.
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