Which rhythm is most likely to demonstrate Ashman's phenomenon?

Ashman’s phenomenon refers to a specific phenomenon observed in patients with atrial fibrillation, particularly in the context of ectopic heartbeats. It occurs when there are irregularities in the conduction of electrical impulses in the heart, especially after a long pause or when there is a change in the timing of the heartbeat.

In atrial fibrillation, the chaotic rhythm and varying intervals can lead to a scenario where a premature ventricular contraction (PVC) occurs following a longer-than-normal interval. This results in a wide QRS complex following a short R-R interval, which is characteristic of Ashman’s phenomenon. The phenomenon highlights the relationship between the timing of the preceding beat and the conduction properties of the heart's tissues.

The other options do not exhibit Ashman’s phenomenon because they either do not have the same irregular rhythm dynamics or lack the prerequisite conditions that lead to its manifestation. For instance, ventricular tachycardia consists of rapid, regular heartbeats that do not typically involve the variability in timing as seen in atrial fibrillation. Supraventricular tachycardia generally involves a faster, regular rhythm with less variability, while a normal sinus rhythm is characterized by a consistent and regular pattern without the pauses needed for Ashman's phenomenon to occur. Thus