title: Myocardial mechanics in a rat model with banding and debanding of the ascending aorta.
abstract: BACKGROUND
  Aortic banding and debanding models have provided useful information on the development and regression of left ventricular hypertrophy (LVH). In this animal study, we aimed to evaluate left ventricular (LV) deformation related to the development and regression of LVH.
  
  
  METHODS
  Minimally invasive ascending aorta banding was performed in rats (10 Sprague Dawley rats, 7 weeks). Ten rats underwent a sham operation. Thirty-five days later, the band was removed. Echocardiographic and histopathologic analysis was assessed at pre-banding, 35 days of banding and 14 days of debanding.
  
  
  RESULTS
  Banding of the ascending aorta created an expected increase in the aortic velocity and gradient, which normalized with the debanding procedure. Pressure overload resulted in a robust hypertrophic response as assessed by gross and microscopic histology, transthoracic echocardiography [heart weight/tibia length (g/m); 21.0 ± 0.8 vs. 33.2 ± 2.0 vs. 26.6 ± 2.8, p < 0.001]. The circumferential (CS) and radial strains were not different between the groups. However, there were significant differences in the degree of fibrosis according to the banding status (fibrosis; 0.10 ± 0.20% vs. 5.26 ± 3.12% vs. 4.03 ± 3.93%, p = 0.003), and global CS showed a significant correlation with the degree of myocardial fibrosis in this animal model (r = 0.688, p = 0.028).
  
  
  CONCLUSIONS
  In this animal study, simulating a severe LV pressure overload state, a significant increase in the LV mass index did not result in a significant reduction in the LV mechanical parameters. The degree of LV fibrosis, which developed with pressure overload, was significantly related to the magnitude of left ventricular mechanics.
authors.affiliation: Division of Cardiology, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jung Sun
authors.initials: JS
authors.lastname: Cho
authors.affiliation: Division of Cardiology, St. Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Cho
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jongho
authors.initials: J
authors.lastname: Lee
authors.affiliation: The University of Debrecen Medical and Health Science Center, Debrecen, Hungary.
authors.forename: Hyun-Duck
authors.initials: HD
authors.lastname: Choi
authors.affiliation: Clinical Research Institute, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Ki Cheol
authors.initials: KC
authors.lastname: Park
authors.affiliation: Department of Pathology, Hwasun Hospital, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Kyung-Hwa
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Clinical Research Institute, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Keum-Jin
authors.initials: KJ
authors.lastname: Yang
authors.affiliation: Division of Cardiology, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Mahn-Won
authors.initials: MW
authors.lastname: Park
authors.affiliation: Division of Cardiology, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Gyung-Min
authors.initials: GM
authors.lastname: Park
authors.affiliation: Division of Cardiology, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Her
authors.affiliation: Division of Cardiology, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Chan Joon
authors.initials: CJ
authors.lastname: Kim
keywords: Aortic banding; Debanding; Left ventricular hypertrophy