• Narrow QRS
• Ectopic (or retrograde) P wave → not from SA node
  • e.g. inverted in lead II

*Don’t need to know how to differentiate with AVRT

Etiology

• Structural heart disease (stretching of the atrium)

  • CHF
  • COPD → pulmonary HTN → stretching of LA

  

Prognosis

• More likely to develop !AFib - Atrial Fibrillation