Author + information
- Received January 7, 2019
- Revision received May 10, 2019
- Accepted June 6, 2019
- Published online October 21, 2019.
- Claire A. Glashan, MDa,∗,
- Bawer J. Tofig, MDb,∗,
- Qian Tao, PhDc,
- Sira A. Blom, BSca,
- Monique R.M. Jongbloed, MD, PhDa,d,
- Jens C. Nielsen, MD, PhDb,
- Peter Lukac, MD, PhDb,
- Steen B. Kristiansen, MD, PhDb and
- Katja Zeppenfeld, MD, PhDa,∗ ()
- aDepartment of Cardiology, Leiden University Medical Center, Leiden, the Netherlands
- bDepartment of Cardiology, Aarhus University Hospital, Aarhus, Denmark
- cDepartment of Radiology, Division of Image Processing, Leiden University Medical Center, Leiden, the Netherlands
- dDepartment of Anatomy and Embryology, Leiden University Medical Centre, Leiden, the Netherlands
- ↵∗Address for correspondence:
Dr. Katja Zeppenfeld, Leiden University Medical Center, Department of Cardiology (C-05-P), P.O. Box 9600, 2300 RC Leiden, the Netherlands.
Objectives This study sought to evaluate the value of combined electrogram (EGM) information provided by simultaneous mapping using micro- and conventional electrodes in the identification of post–myocardial infarction ventricular tachycardia substrate.
Background Ventricular tachycardias after myocardial infarction are related to scars with complex geometry. Scar delineation and ventricular tachycardia substrate identification relies on bipolar voltages (BV) and EGM characteristics. Early reperfusion therapy results in small, nontransmural scars, the details of which may not be delineated using 3.5 mm tip catheters.
Methods Nine swine with early reperfusion myocardial infarction were mapped using Biosense Webster’s QDOT Micro catheter, incorporating 3 microelectrodes at the tip of the standard 3.5 mm electrode. Analysis of EGM during sinus rhythm, right ventricular pacing, and short-coupled right ventricular extrastimuli was performed. The swine were sacrificed and mapping data were projected onto the heart. Transmural biopsies (n = 196) corresponding to mapping points were obtained, allowing a head-to-head comparison of EGM recorded by micro- and conventional electrodes with histology.
Results To identify scar areas using standard electrodes, unique cutoff values of unipolar voltage <5.44 mV, BV <1.27 mV (conventional), and BV <2.84 mV (microelectrode) were identified. Combining the information provided by unipolar voltage and BV mapping, the sensitivity of scar identification was increased to 93%. Micro-EGM were better able to distinguish small near-fields corresponding to a layer of viable subendocardium than conventional EGM were.
Conclusions The combined information provided by multisize electrode mapping increases the sensitivity with which areas of scar are identified. EGM from microelectrodes, with narrower spacing, allow identification of near-fields arising from thin subendocardial layer and layers activated with short delay obscured in EGM from conventional mapping catheter.
↵∗ Drs. Glashan and Tofig contributed equally to this work and are joint first authors.
This study was partially supported by an investigator-initiated grant from Biosense Webster (a Johnson and Johnson company). Dr. Tofig has received research support from the Arvid Nilssons Foundation. Dr. Nielsen has received research support from the Novo Nordisk Foundation (grant NNF16OC0018658); and has received an institutional grant from Abbott Denmark. Dr. Lukac has received an institutional grant from Abbott Denmark and Biosense Webster. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received January 7, 2019.
- Revision received May 10, 2019.
- Accepted June 6, 2019.
- 2019 American College of Cardiology Foundation
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