Supraventricular Tachycardia

• What are the 3 mechanisms that are involved in SVT?


  Re-entry

  Increased automaticity

  Triggered activity
• What are the types of SVT?


  AVNRT

  AVRT

  Atrial tachycardia

  Atrial fibrillation
• What is the most common form of paroxysmal SVT?


  AVNRT
• What are the different types of atrial tachycardia?


  Focal

  Multi-focal (atrial flutter)
• What are the RFs of SVT?


  Coronary artery disease

  MI

  LV systolic dysfunction

  QT syndrome

  Brugada syndrome

  Electrolyte imbalance

  Drug toxicity
• What are the signs & symptoms of SVT?


  Tend to be recurrent & paroxysmal (average duration of episode = 10-15 mins)

  • Palpitations
  • Dizziness or pre-syncope
  • Syncope
  • SOB
  • Chest pain & tightness
  • Progressive fatigue
  • Pounding in head and/or neck
  • Tachycardia
  • Haemodynamic instability
• What are the Inx of SVT?


  Obs

  Full Hx & examination

  ECG

  Bloods (FBC, U&Es, LFTs, TFTs, CRP)

  Echo

  Loop recorder

  Cardiac catheterisation
• What is the acute treatment of SVT?


  A-E assessment

  Synchronised DC cardioversion +/- amiodarone
• What is the treatment of regular & irregular SVT?


  Regular

  • Vagal manoeuvres (1st line)
  • Valsalva & carotid sinus massage
  • IV adenosine (6mg bolus)
  • Verapamil or beta-blocker
  • Synchronised DC cardioversion

  Irregular

  • AF → beta blockers
  • HF → trial of digoxin
  • Onset > 48 hrs → anticoagulation