What defines multifocal PVCs?

What defines multifocal PVCs?

• A. Multiple premature atrial contractions
• B. Single automaticity focus producing identical PVCs
• C. Multiple irritable ventricular automaticity foci producing uniquely shaped PVCs
• D. Uniform PVCs generated from the same ventricular origin

Answer: (C)

Multifocal PVCs, or premature ventricular contractions, are characterized by the presence of multiple irritable ventricular automaticity foci, which means that they originate from different locations within the ventricles. Since these various foci can produce PVCs that have unique shapes, each contraction appears differently on the electrocardiogram. This variability in shape is what distinguishes multifocal PVCs from other types of PVCs, where the contractions might arise from a single focus, leading to uniformity in the appearance of the PVCs.

This differentiation is critical in assessing the underlying cardiac function and potential pathologies. For instance, a greater number of unique shapes may indicate more significant irritation or other underlying cardiac issues. Understanding this helps clinicians gauge the severity of the condition and decide on further diagnostic or therapeutic measures.