Premature ventricular contractions

Premature ventricular contractions (PVCs) are extra, abnormal heartbeats caused by ectopic foci within the ventricles. PVCs are very common and most individuals are asymptomatic, but select patients may present with symptoms such as dizziness or palpitations. Typical ECG findings of PVCs include broad QRS complexes, compensatory pauses, and axis deviation, and may be random or have consistent patterns, such as couplets or bigeminy. Most patients do not require treatment. However, any underlying condition, e.g., myocarditis, must be managed appropriately. Patients with frequent PVCs that cause significant symptoms should receive antiarrhythmic drugs or possibly catheter ablation, as they are at risk for sudden cardiac death.

• Electrolyte imbalances (e.g., hypokalemia, hypomagnesemia)
• Caffeine, alcohol
• Idiopathic
• Cardiovascular disease (e.g., CAD, myocarditis)
• Drugs (e.g., digoxin, psychiatric medications)

• The extra, abnormal heartbeats in PVC are caused by ectopic foci within the ventricles.
• ↓ Diastolic filling time → ↓ stroke volume

• Monomorphic PVC: Each PVC has the same configuration, i.e., identical origin
• Polymorphic PVC: PVCs have different configurations, i.e., multiple foci

• Most patients are asymptomatic.
• Frequent PVCs may lead to lightheadedness, dizziness, palpitations, irregular heartbeat
• Skipped beat

Approach

• Evaluate suspected patients with ECG
• If confirmed, rule out underlying disease (e.g., echocardiography, exercise treadmill stress test) with further procedures

ECG findings

• Common characteristics
  • QRS duration ≥ 120 ms with a block-like QRS morphology
  • There is no P wave before a premature QRS complex.
  • PVCs are often followed by a compensatory pause
• Possible additional characteristics
  • Single PVC
  • Couplet: two PVCs in a row
  • Triplet: three PVCs in a row
  • Bigeminy: one extrasystole after every single sinus beat
  • Trigeminy: one extrasystole after every two sinus beats

PVCs are a common incidental finding on routine ECGs. The detection of them does not require any further workup in patients who are asymptomatic.

Additional procedures

• Only indicated in case of frequent, symptomatic PVCs
• 24-hour Holter monitor
• Exercise stress test
• Echocardiography

• Most patients do not require any treatment
• Treat any underlying disease (e.g., CAD, myocarditis)
• Only treat frequent and significantly symptomatic PVCs
  • Antiarrhythmic therapy
  • Catheter ablation if antiarrhythmic therapy fails