Assoc Prof Harry Mond
February 23, 2026
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36-year old scorpion breeder with “funny” beats in the chest when being stung.
What do you think?
Sinus rhythm, atrial trigeminy with aberration and interpolation
You all got that correct. There is a wonderland of atrial ectopy patterns, provided you keep your eyes open. Let us review some of these patterns.
Trigeminy (red highlight), but no interpolation. Ectopic P wave (red arrow).
A little more complicated.
Sinus arrest; junctional rhythm with bifascicular block and atrial bigeminy (red highlight). This is a pan-conduction defect. Because the ectopics are very premature, the effective heart rate is 30 bpm.
Sinus rhythm (red arrows) with atrial trigeminy (red highlight). A more shorter coupling interval with bigeminy is conducted with aberration (yellow highlight). Also think of long-short intervals.
Sinus rhythm (red arrows) with atrial bigeminy. There are varying coupling intervals resulting in a range of conduction patterns. Normal conduction (red highlight). Left (yellow highlight)and right (blue highlight) bundle branch block aberration.
A Wenckebach AV block sequence can also occur with atrial bigeminy.
It’s all in the timing.
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?
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