Tachycardia: An Overview

Overview

Tachycardia is defined as a heart rate ≥100 bpm. It can be classified based on QRS morphology and rhythm regularity:

• Regular narrow QRS tachycardia:
  • Sinus tachycardia
  • Postural orthostatic tachycardia syndrome
  • Atrial flutter
  • Other supraventricular tachycardias:
    • Atrioventricular (AV) nodal re-entrant tachycardia (AVNRT)
    • AV reciprocating tachycardia (AVRT)

• Irregular narrow QRS tachycardia:
  • Atrial fibrillation
• Regular broad QRS tachycardia:
  • Ventricular tachycardia
• Irregular broad QRS tachycardia:
  • Atrial fibrillation with bundle branch block
  • Polymorphic ventricular tachycardia (including torsades de pointes)