Which term applies when PVCs appear in varied forms?

The term that applies when premature ventricular contractions (PVCs) appear in varied forms is "multifocal." This indicates that the origin of the PVCs varies, resulting in different shapes or morphologies of the contractions on the electrocardiogram (ECG). Each PVC arises from a different point in the ventricle, which leads to the variation in appearance.

Conversely, unifocal PVCs arise from a single ectopic focus within the ventricle, appearing in the same form each time. Monomorphic refers to PVCs that have the same morphology, meaning they originate from the same ectopic focus, while bigeminy denotes a specific pattern where every other heartbeat is a PVC, indicating a regular rhythmic pattern rather than a varying one. Thus, the descriptor for varying forms of PVCs is multifocal, which accurately reflects the presence of multiple points of origin and distinct shapes.