Overview

• A regular, narrow-complex tachycardia with no P waves and a supraventricular origin. (regular = distingiuishing feature from AF which is irregular)
• Atrioventricular nodal re-entry tachycardia (AVNRT) → local re-entry circuit within the AV Node
• Atrioventricular re-entry tachycardia (AVRT) → re-entry circuit forms between atria and ventricles due to presence of accessory pathway (bundle of kent)
  • Wolf-Parkinson-White Syndrome → delta waves (slurred upstroke in QRS) after SVT termination

Making Diagnosis

Clinical Features:

• Syncope
• Palpitations
• Chest Pain + SOB
• Light-headedness
• Tachycardic on physical examination

Investigations:

• ECG → once SVT has been terminated and normal rate and rhythm is established, AVNRT appears normal, however AVRT has delta-waves
  • No P waves
  • SVT = QRS <120ms (narrow-complex). VT = QRS >120ms (broad-complex).
  • SVT ECG
• WPW ECG (short PR interval + slurred upstroke/delta wave)

Management Plan