What Do You Think 17

36-year old scorpion breeder with “funny” beats in the chest when being stung.

What do you think?

• Sinus rhythm (red arrows) with all beats conducting.
• Right bundle branch block ectopics (red highlight)
• Trigeminy
• Ectopic P waves are present (blue arrows)
• There is no compensatory pause.

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.

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A Wenckebach AV block sequence can also occur with atrial bigeminy.

It’s all in the timing.