What Do You Think 3

ECG reported as ventricular pentageminy.

What do you think?

With ventricular pentageminy, there are unifocal ventricular ectopics with fixed coupling intervals every 5^th beat with 4 sinus beats between. In this ECG the coupling intervals are not fixed.

The ventricular ectopics are late (end-diastolic) and lie within the PR intervals.

The earliest ventricular ectopic commences midway through the sinus P wave (red highlight). Another ventricular ectopic (yellow highlight) commences on the downslope of the sinus P wave, whereasa third ectopic is a fusion beat (blue highlight). The time between ventricular ectopics is fixed at 3.6 seconds.

This is most likely ventricular parasystole.

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Ventricular parasystole:

• Rare ECG finding
• Independent, very slow ventricular ectopic focus
• Sinus impulses cannot enter and reset
• Sinus impulses, however, can createrefractoriness of the surrounding myocardium causing an exit block.

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ECG features:

• Unifocal ventricular ectopics
• Variable coupling intervals
• Fixed, usually very slow inter-ectopic intervals
• No ventricular ectopics during the refractory periods
• Fusion beats are common depending on the timing.

The diagnosis is always difficult, controversial and this even applies to cases in the literature.

To be absolutely sure, we need long strips.

Let us look at another ECG example this time with atrial fibrillation.

The relationship or coupling intervals of the ventricular ectopic (red vertical arrow) to the previous sinus beat (red highlight) varies.

The inter-ectopic intervals are all 1600 ms apart with one in the refractory period (blue vertical arrow).