Back to Harry's Corner
Assoc Prof Harry Mond
February 23, 2026
To receive a free PDF copy of The Fundamentals of Electrocardiograph Interpretation by Harry Mond, subscribe to his email blog by entering your email address below.
Purchase a hard cover or paperback copy of The Fundamentals of Electrocardiograph Interpretation by Harry Mond on Amazon.
The most common error in ECG reporting we encounter is differentiating between sinus rhythm and atrial fibrillation particularly in poor quality tracings. Thankfully a confirmed report with this error is very rare. This is because the Techs putting the final stamp of approval on your reports are taught that:
“Atrial fibrillation with a regular ventricular response is actually sinus rhythm until proven otherwise.”— DR HARRY MOND
Such was the case with the accompanying ECG.
Our clever tech changed the rhythm strip and the diagnosis became obvious.
Sinus rhythm with first degree AV block.
We probably see at least one example each day.
Some examples:
This should be repeated but sometimes this is difficult to do.
The major footprint is QRS regularity.
The minor are the P waves.
However, this can sometimes fool you when there are atrial ectopics!!
Assoc Prof Harry Mond
September 11, 2026
Fusion beats are an amalgam of two competing rhythms within the same chamber, atrial or ventricular. They are not “abnormal” beats and are a lesson in timing. For fusion beats to occur, two foci must commence propagation at or near the same time and both contribute to chamber depolarization. Both must be either atrial or ventricular and depending on the contribution of each, the resultant progeny have similarities to one or both parents.
August 26, 2026
Is this the impossible pacemaker ECG? It took me a while to work out what was going on. Is it pacemaker malfunction? What do you think?
July 24, 2026
I came upon these ECG tracings of ventricular tachycardia from a Holter study in a 79-year old asymptomatic female. What do you think?
CardioScan Services Pty Ltd. All rights reserved
