title: Length of the Mitral Isthmus But Not Anatomical Location of Ablation Line Predicts Bidirectional Mitral Isthmus Block in Patients Undergoing Catheter Ablation of Persistent Atrial Fibrillation: A Randomized Controlled Trial.
abstract: BACKGROUND
  Mitral isthmus (MI) ablation is an effective option in patients undergoing ablation for persistent atrial fibrillation (AF). Achieving bidirectional conduction block across the MI is challenging, and predictors of MI ablation success remain incompletely understood. We sought to determine the impact of anatomical location of the ablation line on the efficacy of MI ablation.
  
  
  RESULTS
  A total of 40 consecutive patients (87% male; 54 ± 10 years) undergoing stepwise AF ablation were included. MI ablation was performed in sinus rhythm. MI ablation was performed from the left inferior PV to either the posterior (group 1) or the anterolateral (group 2) mitral annulus depending on randomization. The length of the MI line (measured with the 3D mapping system) and the amplitude of the EGMs at 3 positions on the MI were measured in each patient. MI block was achieved in 14/19 (74%) patients in group 1 and 15/21 (71%) patients in group 2 (P = NS). Total MI radiofrequency time (18 ± 7 min vs. 17 ± 8 min; P = NS) was similar between groups. Patients with incomplete MI block had a longer MI length (34 ± 6 mm vs. 24 ± 5 mm; P < 0.001), a higher bipolar voltage along the MI (1.75 ± 0.74 mV vs. 1.05 ± 0.69 mV; P < 0.01), and a longer history of continuous AF (19 ± 17 months vs. 10 ± 10 months; P < 0.05). In multivariate analysis, decreased length of the MI was an independent predictor of successful MI block (OR 1.5; 95% CI 1.1-2.1; P < 0.05).
  
  
  CONCLUSIONS
  Increased length but not anatomical location of the MI predicts failure to achieve bidirectional MI block during ablation of persistent AF.
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.|Division of Cardiology, Department of Medicine, Medical University of Graz, Austria.
authors: Daniel
authors: D
authors: Scherr
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Nicolas
authors: N
authors: Derval
authors: Kings College London BHF Centre, Cardiovascular Division, NIHR Biomedical Research Centre at Guy's and St. Thomas' NHS Foundation Trust, London, UK.
authors: Manav
authors: M
authors: Sohal
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Patrizio
authors: P
authors: Pascale
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.|Kings College London BHF Centre, Cardiovascular Division, NIHR Biomedical Research Centre at Guy's and St. Thomas' NHS Foundation Trust, London, UK.
authors: Matthew
authors: M
authors: Wright
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Amir
authors: A
authors: Jadidi
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Yuki
authors: Y
authors: Komatsu
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Laurent
authors: L
authors: Roten
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Stephen B
authors: SB
authors: Wilton
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Michala
authors: M
authors: Pedersen
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Khaled
authors: K
authors: Ramoul
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Shinsuke
authors: S
authors: Miyazaki
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Ashok
authors: A
authors: Shah
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Nick
authors: N
authors: Linton
authors: Division of Cardiology, Department of Medicine, Medical University of Graz, Austria.
authors: Martin
authors: M
authors: Manninger
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Arnaud
authors: A
authors: Denis
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Meleze
authors: M
authors: Hocini
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Frederic
authors: F
authors: Sacher
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Michel
authors: M
authors: Haissaguerre
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Pierre
authors: P
authors: Jais
authors: Hôpital Cardiologique du Haut Lévêque, Université Victor-Segalen Bordeaux, Pessac, France.
authors: Sebastien
authors: S
authors: Knecht
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000503:physiopathology*; D013610:Tachycardia / Q000503:physiopathology
keywords: ablation; atrial fibrillation; atrial tachycardia; conduction block; mitral isthmus