A client with a temporary ventricular pacemaker becomes dizzy. The nurse checks the client and the monitor. Click the interval showing electrical output without the expected ventricular response, supporting a capture problem.

C. C contains pacing spikes that are not followed by ventricular QRS complexes.

A visible pacing spike establishes electrical output, not capture. In C, small atrial deflections persist but the expected large ventricular complexes do not follow the spikes. Assess perfusion promptly and escalate; continue to evaluate connections and the cause of failed capture.

The observations are fictional teaching data. Apply the stated context; the selected feature does not by itself replace a complete bedside assessment.

A pacemaker spike is output; a following QRS is electrical ventricular capture.

A pacemaker spike is output; a following QRS is electrical ventricular capture.

A, B and D show a QRS following each pacing spike. Their visible spikes are not by themselves a malfunction. C has output but lacks the expected ventricular response.

• Pacing output versus ventricular capture — A pacemaker spike is output; a following QRS is electrical ventricular capture.
• Comparison with context — Small deflections remain in C and may be mistaken for successful ventricular complexes.