title: Keeping the heart empty and beating: an alternative technique to preserve hypertrophied hearts during valvular surgery.
abstract: BACKGROUND
  To determine whether keeping the heart empty and beating is an effective technique to preserve hypertrophied pig hearts, and to investigate the underlying mechanism.
  
  
  METHODS
  Ten Bama Miniature pigs with hypertrophied hearts were divided into 2 groups (n = 5 in each group). One group underwent normothermic normokalemic simultaneous perfusion (NNSP). The other group was subjected to normothermic hypermokalemic simultaneous perfusion (NHSP) and used as controls. Cardiac contractive function, myocardial energy metabolism and myocardial perfusion were assessed using magnetic resonance imaging. Western blot analysis was carried out to determine the expression of Troponin I (cTnI), Troponin T (cTnT), SM-MHC, Casapase-3 and PARP4. TUNEL assay was used to detect apoptotic cardiomyocytes.
  
  
  RESULTS
  Keeping the heart empty and beating with NNSP improved the preservation of contractile function in comparison with cardioplegic arrest using NHSP. No significant differences existed in the effects of NNSP and NHSP in maintaining myocardial energy metabolism. 13 % perfusion defects areas were found in one heart in the NHSP group, whereas none was found in all other hearts in both groups. The expressions of cTnI, cTnT, Casapase-3 and PARP4 in NHSP group were abundantly increased compared to NNSP group as measured by Western blotting. Conversely, the expression of SM-MHC in NHSP group was reduced compared with NNSP group. The number of TUNEL positive nuclei per mm(2) area was significantly increased in NHSP group compared with NNSP group.
  
  
  CONCLUSIONS
  Keeping the heart beating with NNSP is an alternative technique to preserve hypertrophied hearts during valvular surgery.
authors.affiliation: Department of Cardiovascular Surgery, the First Affiliated Hospital of Harbin Medical University, 23 Youzheng Road, Harbin, Heilongjiang, 150001, China. liu07291977@163.com.
authors.forename: Shangdian
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Cardiovascular Surgery, the First Affiliated Hospital of Harbin Medical University, 23 Youzheng Road, Harbin, Heilongjiang, 150001, China. zhen_1966@163.com.
authors.forename: Zonghong
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Magnetic Resonance Imaging (MRI), the First Affiliated Hospital of Harbin Medical University, Harbin, China. ld95241@126.com.
authors.forename: Lulu
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Magnetic Resonance Imaging (MRI), the First Affiliated Hospital of Harbin Medical University, Harbin, China. ron8744@163.com.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Liu
authors.affiliation: Department of Cardiovascular Surgery, the First Affiliated Hospital of Harbin Medical University, 23 Youzheng Road, Harbin, Heilongjiang, 150001, China. liu_hongyu1963@163.com.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Liu
mesh_terms: D000818:Animals; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D004195:Disease Models, Animal; D006321:Heart / Q000503:physiopathology*; D006349:Heart Valve Diseases / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D007432:Intraoperative Period; D009200:Myocardial Contraction; D010477:Perfusion / Q000379:methods*; D013552:Swine; D013556:Swine, Miniature