What does a pacemaker cause on an ECG?

A pacemaker generates electrical impulses to regulate the heart's rhythm. On an ECG, this is often represented by distinct spikes, known as "pacing spikes," which indicate the electrical activity initiated by the pacemaker. These spikes are critical in recognizing the presence and type of pacing being used. While they appear on the ECG, they should not be misconstrued as pathological; they are the normal manifestations of the pacemaker functioning to stimulate the heart.

In this context, it's important to differentiate these pacing spikes from other components of the ECG that indicate potential problems with heart function. For example, wide QRS complexes can suggest a bundle branch block or other conduction delays, reversed T-wave patterns might indicate issues related to ischemia or other electrical disturbances, and irregular rhythms could imply arrhythmias. Understanding that the pacing spikes are essential signals of the pacemaker's activity means they should be acknowledged and not dismissed. Thus, recognizing and interpreting these spikes correctly is crucial for proper diagnosis and treatment in patients with pacemakers.