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Ventricular trigeminy on an ECG strip

Every third beat is a PVC: normal, normal, PVC.

What to look for

Every third beat is a PVC: normal, normal, PVC, and repeat. It's regularly irregular, with a compensatory pause after each PVC.

Examples

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.

Example 1 · lead II · 6 seconds
II25 mm/s · 10 mm/mV
Rate
82/min underlyingThe whole strip averages 82/min · 8 QRS complexes in 6 seconds × 10 = 80/min
Rhythm
Regularly irregular: a pattern that repeats
P waves
Upright in II, uniform
P to QRS
1:1 for the sinus beats; the PVCs have no P wave
PR
0.15 s
QRS
0.07 s, narrow
PVCs
2 on this strip
Example 2 · lead II · 6 seconds
II25 mm/s · 10 mm/mV
Rate
79/min underlyingThe whole strip averages 76/min · 8 QRS complexes in 6 seconds × 10 = 80/min
Rhythm
Regularly irregular: a pattern that repeats
P waves
Upright in II, uniform
P to QRS
1:1 for the sinus beats; the PVCs have no P wave
PR
0.13 s
QRS
0.08 s, narrow
PVCs
3 on this strip
Example 3 · lead II · 6 seconds
II25 mm/s · 10 mm/mV
Rate
75/min underlyingThe whole strip averages 75/min · 7 QRS complexes in 6 seconds × 10 = 70/min
Rhythm
Regularly irregular: a pattern that repeats
P waves
Upright in II, uniform
P to QRS
1:1 for the sinus beats; the PVCs have no P wave
PR
0.14 s
QRS
0.10 s, narrow
PVCs
3 on this strip

Don't confuse it with

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

Where the criteria come from

Others in the Ventricular group