What are unifocal PVCs?

What are unifocal PVCs?

• A. PVCs that vary in appearance on EKG
• B. PVCs that are identical on EKG, produced by the same focus
• C. PVCs occurring at irregular intervals
• D. PVCs from multiple automaticity foci

Answer: (B)

Unifocal PVCs, or premature ventricular contractions, refer to PVCs that appear identical on an EKG and originate from the same ectopic focus within the ventricles. This uniformity indicates that a single area of the ventricle is responsible for generating these impulses, resulting in a consistent pattern on the EKG. When these PVCs are analyzed, their morphology will be the same due to the fact that they stem from the same site, allowing for the identification of a specific irritability or automaticity within that region of the heart.

In contrast, when PVCs show variation in appearance, as indicated by the other choices, they would be classified as multifocal, stemming from multiple sites of ectopic activity. PVCs occurring at irregular intervals can indicate a fluctuating rhythm or varying ectopic foci, but this does not define unifocal PVCs, which are characterized by their consistent morphology. Understanding the concept of unifocal PVCs is critical for clinicians as it helps in assessing the underlying cardiac conditions that may result in these ectopic beats.