How does a paced rhythm appear on ECG when a pacemaker is functioning correctly?

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Multiple Choice

How does a paced rhythm appear on ECG when a pacemaker is functioning correctly?

When a pacemaker is functioning correctly, its impulses appear on the ECG as pacing spikes that precede the heart’s depolarization. If the impulse captures, a pacing spike is followed by a P wave when atrial pacing or by a QRS complex when ventricular pacing. The rhythm remains regular because the device fires at a fixed interval, so paced beats occur at predictable, even spacing. In dual-chamber pacing you may see spikes before both the P wave and the QRS complex, reflecting pacing of both chambers. This picture differs from intrinsic rhythm without pacing spikes, pacing spikes that occur but with no captured response, or an irregular pattern with intermittent spikes, all of which suggest incomplete or ineffective pacing.

When a pacemaker is functioning correctly, its impulses appear on the ECG as pacing spikes that precede the heart’s depolarization. If the impulse captures, a pacing spike is followed by a P wave when atrial pacing or by a QRS complex when ventricular pacing. The rhythm remains regular because the device fires at a fixed interval, so paced beats occur at predictable, even spacing. In dual-chamber pacing you may see spikes before both the P wave and the QRS complex, reflecting pacing of both chambers. This picture differs from intrinsic rhythm without pacing spikes, pacing spikes that occur but with no captured response, or an irregular pattern with intermittent spikes, all of which suggest incomplete or ineffective pacing.

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