AV junctional tachycardia

Introduction

A non paroxysmal condition with narrow complex & regular rhythm

@ 60-130/min thought to arise from increased automaticity of the AV node.

Etiology

• myocardial infarction
• catecholamine excess
• digitalis toxicity
• post cardiac surgery
• rheumatic fever

Diagnostic procedures

• electrocardiogram:
  • atrial rate generally 60-130/min
  • intact retrograde conduction
    • p-waves
      • inverted
      • occur during or immediately after the QRS complex
  • retrograde conduction block
    • competitive AV dissociation
    • normal p-waves non-conducted at a rate slower than ventricular rate
  • ventricular rate 60-130/min
    • QRS may be normal
    • QRS may reflect bundle-branch block secondary to increased rate

Management

• arrhythmia generally resolves with correction of underlying precipitating factors
  • discontinue offending pharmacologic agents
  • exogenous catecholamines
  • digitalis
• anti-arrhythmic agents
  • phenytoin or lidocaine for digitalis toxicity
  • beta blocker, Ca+2 channel blocker
  • amiodarone is drug of choice is LCEF < 40%
• NO DC cardioversion
• K+ for digitalis toxicity
• Mg+2 supplementation
• atrial overdrive pacing in patients with hemodynamic compromise in setting of competitive AV dissociation
• catheter ablation

More general terms

• AV junctional rhythm
• narrow complex tachycardia