title: Visualization of the Critical Isthmus by Tracking Delayed Potential in Edited Windows for Scar-Related Ventricular Tachycardia.
abstract: OBJECTIVE
  Identifying the critical isthmus of slow conduction is crucial for successful treatment of scar-related ventricular tachycardia. Current 3D mapping is not designed for tracking the critical isthmus and may lead to a risk of extensive ablation. We edited the algorithm to track the delayed potential in order to visualize the isthmus and compared the edited map with a conventional map.
  
  
  METHODS
  We marked every point that showed delayed potential with blue color. After substrate mapping, we edited to reset the annotation from true ventricular potential to delayed potential and then changed the window of interest from the conventional zone (early, 50-60%; late, 40-50% from peak of QRS) to the edited zone (early, 80-90%; late, 10-20%) for every blue point. Finally, we compared the propagation maps before and after editing.
  
  
  RESULTS
  We analyzed five scar-related ventricular tachycardia cases. In the propagation maps, the resetting map showed the critical isthmus and entrance and exit sites of tachycardia that showed figure 8 reentry. However, conventional maps only showed the earliest ventricular activation sites and searched for focal tachycardia. All of the tachycardia cases were terminated by ablating the area around the isthmus.
  
  
  CONCLUSIONS
  Identifying the channel and direction of the critical isthmus by a new editing method to track delayed potential is essential in scar-related tachycardia.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Ju Youn
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Woo-Seung
authors.initials: WS
authors.lastname: Shin
authors.affiliation: Division of Cardiology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Tae-Seok
authors.initials: TS
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Sung-Hwan
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Sung-Won
authors.initials: SW
authors.lastname: Jang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hui-Nam
authors.initials: HN
authors.lastname: Pak
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Gi-Byoung
authors.initials: GB
authors.lastname: Nam
authors.affiliation: Division of Cardiology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Man Young
authors.initials: MY
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Tai-Ho
authors.initials: TH
authors.lastname: Rho
authors.affiliation: Division of Cardiology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Yong Seog
authors.initials: YS
authors.lastname: Oh
keywords: Delayed potential; Electroanatomical mapping; Scar-related ventricular tachycardia