I awoke feisty this morning and decided to be controversial.
How would you interpret this ECG?
The rhythm is atrial fibrillation with ventricular bigeminy. Or is it?
Firstly, let us look at ventricular bigeminy:
The footprints are:
Trigeminy is similar:
Now, let us return to our original ECG.
So what else could this be?
Consider ventricular parasystole.
Our ECG conforms to these features (no fusion beats).
To be absolutely sure, we need longer strips and hence the controversy.
Here is an example with fusion beats:
However, the coupling intervals are fixed.
Hence longer tracings are required to confirm the diagnosis.
Here is another confusing tracing:
Interpolated ventricular quadrigeminy
Is ventricular parasystole really rare?
It is rarely looked for and strips are not long enough.
Is there a pseudo-ventricular parasystole?
Consider very slow asynchronous ventricular pacing (VOO) and sinus rhythm.
What about atrial parasystole?
It is said to occur, and I believe I have seen it.
One of the arrhythmias of digitalis toxicity and hence not seen today.
It’s all in the timing
In 49+ years as a practicing cardiologist, Dr Harry Mond has published 260+ published manuscripts & books. A co-founder of CardioScan, he remains Medical Director and oversees 500K+ heart studies each year.
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