Which premature complex requires monitoring and is characterized by a single, premature beat from the ventricles that can be followed by a pause?

• A. Couplets
• B. Unifocal premature ventricular complexes
• C. Multifocal premature ventricular complexes
• D. Premature ventricular complex

Answer: (D)

The main idea here is recognizing a ventricular ectopic beat that interrupts the normal rhythm and occurs earlier than expected. This is a premature ventricular complex. You can spot it on ECG as a wide, bizarre-looking QRS complex that appears without a preceding P wave and arrives sooner than the next expected beat, often followed by a compensatory pause as the heart resets.

This single premature beat is what sets it apart from other patterns: two consecutive premature beats would be a couplet; PVCs that look the same on all beats come from one focus (unifocal), while PVCs with varying shapes come from multiple foci (multifocal). The description emphasizes a lone premature beat with a possible pause, which is exactly a premature ventricular complex. In clinical terms, this can be benign, but it’s important to monitor frequency and pattern because frequent PVCs or certain configurations can indicate underlying issues needing further evaluation.