Elimination of purkinje fibers by electroporation reduces ventricular fibrillation vulnerability

Christopher Livia, Alan Sugrue, Tyra Witt, Murray D. Polkinghorne, Elad Maor, Suraj Kapa, Helge I. Lehmann, Christopher V. DeSimone, Atta Behfar, Samuel J. Asirvatham, Christopher J. McLeod

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

Background-The Purkinje network appears to play a pivotal role in the triggering as well as maintenance of ventricular fibrillation. Irreversible electroporation (IRE) using direct current has shown promise as a nonthermal ablation modality in the heart, but its ability to target and ablate the Purkinje tissue is undefined. Our aim was to investigate the potential for selective ablation of Purkinje/fascicular fibers using IRE. Methods and Results-In an ex vivo Langendorff model of canine heart (n=8), direct current was delivered in a unipolar manner at various dosages from 750 to 2500 V, in 10 pulses with a 90-µs duration at a frequency of 1 Hz. The window of ventricular fibrillation vulnerability was assessed before and after delivery of electroporation energy using a shock on T-wave method. IRE consistently eradicated all Purkinje potentials at voltages between 750 and 2500 V (minimum field strength of 250-833 V/cm). The ventricular electrogram amplitude was only minimally reduced by ablation: 0.6±2.3 mV (P=0.03). In 4 hearts after IRE delivery, ventricular fibrillation could not be reinduced. At baseline, the lower limit of vulnerability to ventricular fibrillation was 1.8±0.4 J, and the upper limit of vulnerability was 19.5±3.0 J. The window of vulnerability was 17.8±2.9 J. Delivery of electroporation energy significantly reduced the window of vulnerability to 5.7±2.9 J (P=0.0003), with a postablation lower limit of vulnerability=7.3±2.63 J, and the upper limit of vulnerability=18.8±5.2 J. Conclusions-Our study highlights that Purkinje tissue can be ablated with IRE without any evidence of underlying myocardial damage.

Original languageEnglish (US)
Article numbere009070
JournalJournal of the American Heart Association
Volume7
Issue number15
DOIs
StatePublished - Aug 1 2018

Keywords

  • Ablation
  • Direct current ablation
  • Irreversible electroporation
  • Purkinje fibers
  • Ventricular fibrillation
  • Window of vulnerability

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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