Recurrent VT with ICD shocks

Raja Selvaraj JIPMER

Clinical presentation

Presentation (2012, elsewhere)

  • 45 year old male
  • Dyspnea / fatigue
  • LV dysfunction - EF 40%
  • CAG normal

2016

  • Palpitations
  • ? Documented tachycardia
  • What is appropriate management if sustained VT ?

ECG

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NICM / sustained VT

  • Beta blockers
  • Amiodarone
  • ICD
  • CRTD

AVID

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Further course

  • Single chamber ICD implanted
  • Multiple shocks in Jan 2017
  • ICD interrogation - appropriate therapy for VT
  • Already on Amiodarone 200 mg OD
  • Opinion in different hospitals

ICD, VT on Amiodarone - what would you do?

  • Increase dose of amiodarone
  • Add Mexilitene
  • RF ablation
  • Check ICD

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Further course

  • May 2017 - Multiple NSVT
  • Increased Amio 300 mg OD
  • Jan 2018 - 4 shocks
  • Came asking for ICD to be turned off
  • Device interrogation - 180 episodes of NSVT since Jan 2018

ECG - Where is origin ?

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ECG clues for epicardial origin

  • Interval criteria
    • Pseudo delta
    • Intrinsicoid deflection time
    • Shortest RS
    • Maximum deflection index
  • Morphologic criteria
    • q wave in lead I
    • q wave in inferior leads

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ECG Criteria to Identify Epicardial Ventricular Tachycardia in Nonischemic Cardiomyopathy. Ermengol Vall├Ęs, Victor Bazan and Francis E. Marchlinski. Circulation: Arrhythmia and Electrophysiology. 2010;3:63-71

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Imaging

  • Echo: LVEF 40-45%
  • MRI: Scar in IVS / lateral LV
  • Mapping and ablation plan ?

Endocardial mapping

Initial approach

  • Attempted percutaneous pericardial access
  • Unable to access pericardial space
  • LV endocardial map

LV voltage map (RV pacing)

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What to do?

  • Unipolar voltage
  • Induce VT
  • Empiric ablation

Endocardial unipolar voltage predicts epicardial bipolar voltage

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  1. Hutchinson … Marchlinski. Endocardial unipolar voltage mapping to detect epicardial ventricular tachycardia substrate in patients with nonischemic left ventricular cardiomyopathy. Circ Arrhythm Electrophysiol 2011;4:49

Tachy induction - what is interpretation ?

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VT - What is the V-H relationship ?

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VT map - LV and RV

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RV entrainment

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Epicardial mapping

Subsequent course

  • Subxiphoid window
  • Wire in pericardial space
  • Agilis epi sheath

Wire in pericardial space

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Setup

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Epicardial map - Rt Lat

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Epicardial low voltage - fat / scar

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Distinguishing epicardial fat from scar: Analysis of electrograms using high-density electroanatomic mapping in a novel porcine infarct model. Shivkumar. Heart Rhythm 2010

Epicardial map - Lt Lat

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Substrate in inferolateral LV

  • what are potential innocent bystanders ?
  • Phrenic nerve
  • Coronary arteries

LCA angiogram

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Signal during VT - where is the catheter

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Where is the catheter ?

  • Outer loop
  • Isthmus entrance
  • Isthmus exit
  • Isthmus center
  • Dont know / cant tell

Entrainment

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Where is the catheter ?

  • Outer loop
  • Isthmus entrance
  • Isthmus exit
  • Isthmus center
  • Dont know / cant tell

Further course

  • Started ablating
  • Terminated with ablation further lower
  • Subsequent ablation to eliminate late potentials

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Post ablation VT induction

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Learning points

  • Identification of epicardial VT on ECG
  • Unipolar voltage to identify epicardial scar
  • Sub-xiphoid window
  • Pitfalls / perils in epicardial mapping