title: A new cryoenergy for ventricular tachycardia ablation: a proof-of-concept study.
abstract: BACKGROUND
  Lack of transmural lesion formation during radiofrequency (RF) ablation for ventricular tachycardia (VT) is an important determinant of arrhythmia recurrence. The aim of this proof-of-concept study was to evaluate safety and efficacy of a new and more powerful cryoablation system for ventricular ablation.
  
  
  RESULTS
  Five healthy female sheep (59 ± 6 kg) underwent a surgical sternotomy for epicardial and endocardial access [endocardial access via right atrial appendage and left ventricular (LV) apex]. A cryoablation system with liquid nitrogen (IceCure) was used to create 3 min freezes at the right ventricle (RV). Left ventricular cryoablation was performed with either a 6 min or 2 × 4 min freezes. To assess safety, ablation was also performed on the mid left anterior descending artery and the proximal coronary sinus. A total of 45 lesions were created (RV epicardial, n = 12; LV epicardial, n = 18; RV endocardial, n = 7; LV endocardial, n = 8; LAD, n = 4; and CS, n = 4). The mean lesion volume was 5055 ± 92 mm3 (length: 32 ± 4.6 mm, width: 16.0 ± 6.4 mm, and depth: 11.2 ± 4.4 mm). Lesions were transmural in 28/45 (62%) and >10 mm in depth in 35/45 (78%). Of the endocardial lesions, 12/15 were transmural (80%). There was no benefit of the bonus freeze in LV lesions (6 vs. 2 × 4 min: 6790 ± 44 vs. 5595 ± 63 mm3; P = 0.44). All ablated vascular structures appeared macroscopically normal without acute stenosis. One animal died due to incessant Ventricular fibrillation (VF).
  
  
  CONCLUSIONS
  Our results indicate that a more powerful cryoablation system is able to create large, transmural ventricular lesions from both the endocardium and the epicardium. The technology may hold potential for both surgical and catheter-based VT ablation in humans.
authors.affiliation: Departments of Cardiology and Radiology, Hôpital Haut-l'évêque, CHU Bordeaux, 33604 Bordeaux-Pessac, France.|LIRYC Institute, IHU LIRYC ANR-10-IAHU-04, Bordeaux, France.|Department of Cardiology, Clinic Im Park, Zurich, Switzerland.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Berte
authors.affiliation: Departments of Cardiology and Radiology, Hôpital Haut-l'évêque, CHU Bordeaux, 33604 Bordeaux-Pessac, France.|LIRYC Institute, IHU LIRYC ANR-10-IAHU-04, Bordeaux, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sacher
authors.affiliation: Departments of Cardiology and Radiology, Hôpital Haut-l'évêque, CHU Bordeaux, 33604 Bordeaux-Pessac, France.|LIRYC Institute, IHU LIRYC ANR-10-IAHU-04, Bordeaux, France.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Wielandts
authors.affiliation: Departments of Cardiology and Radiology, Hôpital Haut-l'évêque, CHU Bordeaux, 33604 Bordeaux-Pessac, France.|LIRYC Institute, IHU LIRYC ANR-10-IAHU-04, Bordeaux, France.
authors.forename: Saagar
authors.initials: S
authors.lastname: Mahida
authors.affiliation: Departments of Cardiology and Radiology, Hôpital Haut-l'évêque, CHU Bordeaux, 33604 Bordeaux-Pessac, France.|LIRYC Institute, IHU LIRYC ANR-10-IAHU-04, Bordeaux, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Pillois
authors.affiliation: Department of Cardiology, Royal Perth Hospital, Perth, Australia.
authors.forename: Rukshen
authors.initials: R
authors.lastname: Weerasooriya
authors.affiliation: LIRYC Institute, IHU LIRYC ANR-10-IAHU-04, Bordeaux, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Bernus
authors.affiliation: Departments of Cardiology and Radiology, Hôpital Haut-l'évêque, CHU Bordeaux, 33604 Bordeaux-Pessac, France.|LIRYC Institute, IHU LIRYC ANR-10-IAHU-04, Bordeaux, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Jaïs
mesh_terms: D000200:Action Potentials; D000818:Animals; D003452:Cryosurgery / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D004195:Disease Models, Animal; D004867:Equipment Design; D005260:Female; D006339:Heart Rate; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D000075082:Proof of Concept Study; D034561:Sheep, Domestic; D017180:Tachycardia, Ventricular / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016277:Ventricular Function, Left
keywords: Ablation; Animal study; Cryo energy; Ventricular tachycardia