Introduction

Premature Ventricular Complexes – PVCs (aka ventricular ectopic beats VEBs) are a common, and usually (but not always) benign cardiac rhythm abnormality.

It typically present with palpitations, although many cases are asymptomatic.

  • Palpitations often intermittent and brief
  • May cause a great deal of anxiety for patients

Beware of patients with syncopal episodes or palpitations (or syncope) associated with exercise.

Most patients can be managed with simple reassurance. Beta-blocker, or calcium channel blocker (second line) can reduced symptomatic episodes.

Terminology

There are a lot of names for the same condition:

  • PVC = VEB = ventricular ectopic = ventricular extrasystole
  • Bigeminy – refers to a scenario where every normal contraction is followed by a PVC
  • Trigeminy – every 3rd contraction is a PVC
  • Couplet – two PVC consequtively
  • Non-sustained¬†Ventricular Tachycardia – NSVT –¬†3 or more consecutive PVCs

Pathology

A PVC is an electrical stimulus of the ventricles which occurs within the ventricles themselves – i.e. it does not come from the atria.

  • They originate from an ‘ectopic’ (i.e. not the usual place) location in the ventricles
  • Caused by groups of pacemaker cells throughout the conduction system that start to operate independently of the normal stimulation
  • They can be classified as:
    • Unifocal –¬†every PVC appears identical – all arise from he same ectopic location
    • Multifocal –¬†different PVC morphologies – indicated multiple ectopic sites

Other types of ectopic also exist:

  • Atrial ectopics
  • Junctional ectopics

Causes

Diagnosis

A PVC can be discerned on ECG by:

  • Absence of P wave before the QRS
  • Wider, taller QRS complex (>120ms)
  • Often immediately follows a T wave
  • Has a discordant T wave (T wave point in opposite direction to major portion of QRS)

Usually, one or more PVCs will be visible on an ECG – even if the patient is asymptomatic at the time of presentation

  • Consider 24-hour ECG (Holter Monitor) if normal ECG at the time of presentation
PVC on ECG

PVC on ECG. Note the widened and roller QRS, and discordant T wave.

 

Bigeminy on ECG

Bigeminy on ECG. Note the widened and taller QRS complex after each normal cycle.

Management

  • Rule out structural heart disease with an echo
    • If present – refer to cardiology
  • Assess for risk of acute cardiac mortality
    • FHx of sudden cardiac death
    • Previous history of syncope?
      • Especially if associated with exercise
    • Increase in palpitations after exercise
  • If all the above is normal:

References

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