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Premature Ventricular Contractions (PVCs)

normal
Lead II
25 mm/s10 mm/mV
HR72bpm
RR833ms
QT358ms
Type

Every third beat is a PVC: two normal beats followed by one wide ectopic beat, repeating.

Updated

On the trace

Read the strip in this order.

Try each step, then check it.
  1. Find the groups of three.
    Show Two narrow sinus beats, then one wide PVC, repeating.
  2. Check the coupling.
    Show Each PVC sits the same distance after the sinus beat before it: one focus. A varying interval would suggest more than one.
  3. Check the pause.
    Show A fully compensatory pause follows each PVC, so every group takes exactly three sinus cycles.
  4. Count the rate.
    Show All complexes together give the sinus rate, here 72 bpm; only two in every three are normal beats.

How to recognise it

FeatureValueNotes
PatternNormal–Normal–PVCThe three-beat group repeats.
Coupling intervalFixedThe same sinus-to-PVC interval in every group.
PVC burden~33%On this strip, well above the 10% at which a Holter and echocardiography are worth doing.
RateMatches the sinus rateThe compensatory pauses keep the overall count equal to the sinus rate.

The strip

Thirty seconds of ventricular trigeminy in lead II, drawn by the simulator. Work through the steps above on it: find the groups of three, then check the coupling and the pause.

Management

1

Measure the real burden

A strip shows about 33%; a 24-hour Holter shows the daily load. If it stays high, echocardiography screens for early LV dysfunction.

2

Look for the cause

Electrolytes (potassium, magnesium), a medication review, and ischaemia assessment where appropriate. Correcting low potassium alone can break the pattern.

Differential

Premature Ventricular Contractions (PVCs)

The same beats without a fixed pattern: wide beats at irregular intervals are isolated ectopy.

Ventricular Bigeminy

A PVC after every sinus beat: a two-beat cycle and a 50% burden. The two can alternate in the same patient as conditions change.

The full picturePremature Ventricular Contractions (PVCs)Mechanism, causes and management are covered in the base rhythm.

References

  1. 2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death — European Heart Journal, 2022