Patient Care Technician (PCT) AAH Practice Exam

What are Unifocal PVCs?

1. Early contractions from multiple sites

2. Early contractions from a single site

3. Regularly occurring ventricular contractions

4. Ventricular contractions with variable timing

The correct answer is: Early contractions from a single site

Unifocal PVCs, or unifocal premature ventricular contractions, arise from a single ectopic focus within the ventricles. This means that each PVC originates from the same site, resulting in a consistent shape and pattern on an electrocardiogram (ECG). This distinct origin indicates that the electrical impulse causing these contractions comes from one specific area of the heart muscle rather than multiple locations. In contrast, early contractions from multiple sites would refer to multifocal PVCs, which are characterized by variations in the shape and timing of the contractions as they stem from different ectopic foci. Regularly occurring ventricular contractions would imply a sustained rhythm or predictable pattern which does not classify as PVCs since they are irregular. Lastly, ventricular contractions with variable timing would represent an irregular rhythm, which would again not align with the consistent nature of unifocal PVCs. Thus, understanding that unifocal PVCs originate from a single site helps differentiate them from other types of PVCs and arrhythmias.