What Do You Think 10

47-year old astronaut with nervous stutter.

What do you think?

• The rhythm is not sinus but rather junctional as there are no P waves and the QRS complexes are narrow (red highlight).
• The first junctional complex has no inverted P wave in the upslope of the T wave, whereas the next two have (red vertical arrows).
• These inverted P waves conduct to the ventricle; the second with normal conduction (yellow highlight) and the first with aberration (blue highlight).

Junctional rhythm with retrograde conduction, echo beats and normal or aberrant conduction.

It’s all in the timing.