A nurse is caring for a client with a ventricular pacemaker who is on ECG monitoring. The nurse understands that the pacemaker is functioning properly when which of the following appears on the monitor strip?

Choice A reason: A ventricular pacemaker functions properly when spikes appear before each QRS complex on the ECG, indicating the device is triggering ventricular depolarization. The spike represents the electrical impulse delivered to the ventricle, ensuring contraction in clients with impaired conduction, maintaining adequate cardiac output. Choice B reason: Pacemaker spikes after the QRS complex indicate improper functioning, as the pacemaker should initiate ventricular depolarization before the QRS. Post-QRS spikes suggest the device is not pacing correctly, failing to stimulate the ventricle at the appropriate time, which could lead to ineffective heart contractions. Choice C reason: Pacemaker spikes before P waves are characteristic of atrial pacemakers, not ventricular ones. A ventricular pacemaker targets ventricular contraction, producing spikes before the QRS complex. Spikes before P waves would not address ventricular pacing needs in a client with a ventricular pacemaker. Choice D reason: Pacemaker spikes with T waves indicate malfunction, as the T wave represents ventricular repolarization, not depolarization. A ventricular pacemaker should fire before the QRS to initiate contraction. Spikes during T waves could cause dangerous arrhythmias, as pacing during repolarization disrupts normal cardiac rhythm.