title: Prevention of postsurgical atrial tachycardia with a modified right atrial free wall incision.
abstract: BACKGROUND
  Most postsurgical macroreentry atrial tachycardias (PS-MATs) are atriotomy related; however, underlying mechanisms and prevention remain undefined.
  
  
  OBJECTIVE
  The purpose of the present study was to investigate the electrophysiological and histologic bases of right atriotomy incision arrhythmogenicity and whether a modified atriotomy that extends the incisional line to the tricuspid annulus (TA) and inferior vena cava (IVC) prevents PS-MAT.
  
  
  METHODS
  Atrial arrhythmia induction and electrophysiological and histologic characteristics were studied 8 weeks after right atriotomy in 30 adult swine according to incision distance to TA or IVC (groups A, B, and C: broad, narrow, and closed corridors, respectively; group D, no-incision sham; n = 6 per group, except n = 12 for group B).
  
  
  RESULTS
  Sustained PS-MATs were induced and mapped in the broad- and narrow-corridor groups (A, 1 of 6 [16.7%] vs B, 5 of 12 [41.7%]) but not in the closed-corridor (C) or sham (D) groups (P = .087). With 20-ms pacing cycle-length decrements (from 350 to 270 ms), mean conduction time over 20 mm at the atriotomy-to-TA corridor was 29.2 ± 2.2, 31.0 ± 4.2, 26.0 ± 1.9, and 17.0 ± 1.4 ms for 5 and 10 mm (both group B), 15 mm (group A), and sham incision (P = .017), respectively. Conduction properties correlated with histologic findings: the wider the corridor, the healthier its tissue. In group C (modified atriotomy), both corridors were replaced by dense scar with complete conduction block.
  
  
  CONCLUSIONS
  Atriotomy corridor width determines conduction properties and contributes to arrhythmogenicity. A modified right atriotomy that extends to the TA and IVC prevents PS-MAT.
authors: Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Gang
authors: G
authors: Yang
authors: Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Xianfeng
authors: X
authors: Du
authors: Division of Cardio-Thoracic Surgery, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Buqing
authors: B
authors: Ni
authors: Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Hongwu
authors: H
authors: Chen
authors: Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Rundi
authors: R
authors: Qi
authors: Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Cheng
authors: C
authors: Cai
authors: Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Yin
authors: Y
authors: Fang
authors: Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Bing
authors: B
authors: Yang
authors: Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Weizhu
authors: W
authors: Ju
authors: Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Fengxiang
authors: F
authors: Zhang
authors: Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Mingfang
authors: M
authors: Li
authors: Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Kai
authors: K
authors: Gu
authors: Division of Cardio-Thoracic Surgery, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China.
authors: Yongfeng
authors: Y
authors: Shao
authors: Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China. Electronic address: chenminglong@njmu.edu.cn.
authors: Minglong
authors: M
authors: Chen
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D001282:Atrial Flutter / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000379:methods; D004195:Disease Models, Animal; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D006325:Heart Atria / Q000503:physiopathology / Q000601:surgery; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery; D007430:Intraoperative Care / Q000379:methods; D008955:Models, Cardiovascular; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology / Q000517:prevention & control; D013552:Swine; D016896:Treatment Outcome; D014682:Vena Cava, Inferior / Q000601:surgery
keywords: Atrial tachycardia; Atriotomy; Macroreentry