Recurrence of AVNRT. How do I approach the second ablation?

Raja Selvaraj
Cardiac Electrophysiologist
Professor of Cardiology
JIPMER

What we will discuss

• Making the correct diagnosis
• AVNRT using RIE - Addressing causes of failed ablation
• AVNRT using non RIE slow pathway - Identification and ablation
• Fast pathway ablation
• Use of electroanatomical mapping

Making the correct diagnosis

Diagnosis of AVNRT

• Narrow QRS / Wide QRS with normal HV
• 1:1 VA, could be different
• Short VA, could be variable
• VAV response with VOP
• cPPI-TCL > 115

Difficult diagnosis

• VA > 70, AVNRT vs AVRT (concealed septal AP)
  • VOP - cPPI-TCL, SA-VA, VA dissociation
  • His refractory PVCs
  • Maneuvers in sinus rhythm to identify AP
• Unable to perform VOP - AVNRT vs AT

AVNRT or AT - VOP does not entrain

AVNRT vs AT (unable to perform VOP)

• VA linking
• AH during tachycardia versus pacing
• Adenosine
• Simultaneous AV pacing
• ? differential PPI

AVNRT or AT - Simultaneous AV pacing

AVNRT or AT - Simultaneous AV pacing

AVNRT or AT - Simultaneous AV pacing

JT or AVNRT

JT or AVNRT

NV / NF ORT

Correct diagnosis - RIE ablation fails

RIE ablation

Most common reason for failure - Poor stability

• Fluoroscopic appearance, EGM and impedance stability, impedance fall during ablation
• Use a sheath
• SR0 / Agilis
• Sedation / GA / Cryo

Improving contact

VA block during junctionals

VA block during junctionals

Non RIE slow pathway

Other slow AV nodal inputs

• Left inferior extension
• Left inferolateral
• Anteroseptal

LIE slow pathway

Bystander RIE and Resetting response

Reset from RIE

Reset from LIE

LIE ablation within CS

LIE ablation endocardial

Fast pathway ablation - Still relevant ?

Fast pathway ablation

• Two patients (out of — AVNRT ablations)
• Patient 1
  • 52 M, previous failed ablation for AVNRT
  • PR 220 ms
  • Failed ablation of RIE
• Patient 2
  • 37 F, previous failed ablation for AVNRT
  • Recurrent drug refractory episodes
  • Failed ablation of RIE and LIE
  • Pre PR 160, post PR 210
• Both patients successful, no AV block, no recurrences

Electroanatomic mapping

Electroanatomic mapping - Myths

• Will help make correct diagnosis
• Improves success rate of ablation
• Reduces risk of complications

High density mapping - Approaches

High density mapping - Approaches

• Pivot point
• Fractionated potentials during tachycardia
• Low voltage bridge

Summary - In a difficult AVNRT ablation consider

• Is the diagnosis correct ?
• Is RIE contact and stability good ?
• Is RIE a bystander and another slow pathway involved ?
• Could FP ablation be considered (refractory tachycardia, very symptomatic, all SP ablation failed, higher risk of AV block)