Which of the following are characteristic of a PVC?

A premature ventricular contraction (PVC) is characterized by a couple of distinct features that help differentiate it from other cardiac events. One of the most notable characteristics is that the QRS complex is wide and bizarre. This occurs because PVCs originate from the ventricles rather than the atria, and the ventricular conduction system does not propagate impulses in the same synchronized manner as normal sinus rhythm. As a result, the electrical impulse travels through the ventricles more slowly, leading to a QRS complex that is broader than 0.12 seconds and appears atypical on an electrocardiogram (ECG).

The other characteristics mentioned do not apply to PVCs. For instance, an elongated PR interval is associated with conditions like atrioventricular block rather than PVCs. Additionally, PVCs usually occur in the context of a normal or fast heart rate depending on the underlying rhythm, and they are not indicative of a slow heart rate. PVCs do not have a consistent relationship with P waves; in fact, they can occur with or without preceding P waves, and when present, the P waves can be located differently relative to the QRS complex.