Premature junctional complex

ECG Findings

  • P wave be either:
    • Absent
    • Abnormal P wave with short PR < 120ms
    • Retrograde P waves, which may be inverted, in inferior leads
  • PJC arrives before next sinus beat
  • Followed by compensatory pause
  • From AV node region, with ventricular response usually normal, so QRS complexes usually narrow
  • If conduction abnormal, may have RBBB morphology

Clinical Significance

  • Less common than PVCs or PACs
  • Differentiate from WPW (short PR)
  • May be seen in healthy individuals with no clinical significance
  • Or in pathology such as valvular disease, drug toxicity, electrolyte disorder
WPW with PJC underlined in red