A pacing spike before every P wave, each followed by a narrow QRS.
A pacing spike before every P wave, and each P followed by a normal narrow QRS. The pacemaker drives the atria, and the heart's own conduction does the rest. The rate is the pacemaker's, so it's exactly regular.
Each strip is 6 seconds of lead II, drawn to scale (25 mm a second, 10 mm a millivolt), so you can count boxes the way you would on paper. Each one is a different example, measured below it.
Two pacing spikes each beat: one before the P wave, one before the wide QRS.
Regular at 60-100/min, an upright P before every QRS, a PR of 0.12-0.20 s and a narrow QRS.
Sinus rhythm with every P conducted, but a constant PR over 0.20 s.
Want a new strip every time? The ECG Drill in the app draws a fresh, measured example on every try and steers you toward the rhythms you miss. It's part of the Paramedic level, and you can try 5 strips a day free.
Try the ECG Drill
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