What arrhythmia would likely show QRS complexes that are distorted in shape and correlate with a fusion beat?

The identification of distorted QRS complexes that correlate with a fusion beat indicates the presence of a fusion between a normal ventricular contraction and an ectopic ventricular impulse, which is characteristic of ventricular ectopic beats. These beats originate in the ventricles and can produce abnormal shapes due to the disrupted conduction pathway compared to normal sinus rhythm.

In the context of the arrhythmia types listed, ventricular ectopic beats are known for their ability to create QRS complexes that may vary in morphology, especially when they occur in a pattern that gives rise to fusion beats. A fusion beat occurs when a normal impulse coincides with an ectopic impulse, creating a hybrid electrical impulse that can manifest as a unique shape on the electrocardiogram (ECG).

In contrast, conditions such as supraventricular tachycardia would generally produce narrow QRS complexes unless there is an aberrant conduction, while ventricular fibrillation presents as chaotic, unrecognizable electrical activity with no defined QRS complexes. A wandering atrial pacemaker is characterized by changes in the P wave morphology, not the QRS shape, as it originates from varying atrial foci.

Thus, ventricular ectopic beats are the arrhythmia closely associated with the characteristics of distorted QRS complexes and