title: Strain-related regional alterations of calcium-handling proteins in myocardial remodeling.
abstract: BACKGROUND
  Cardiac remodeling has been shown to have deleterious effects at both the global and local levels. The objective of this study is to investigate the role of strain in the initiation of structural and functional changes of myocardial tissue and its relation to alteration of calcium-handling proteins during cardiac remodeling after myocardial infarction.
  
  
  METHODS
  Sixteen sonomicrometry transducers were placed in the left ventricular free wall of 9 sheep to measure the regional strain in the infarct, adjacent, and remote myocardial regions. Hemodynamic, echocardiographic, and sonomicrometry data were collected before myocardial infarction, after infarction, and 2, 6, and 8 weeks after infarction. Regional myocardial tissues were collected for calcium-handling proteins at the end study.
  
  
  RESULTS
  At time of termination, end-systolic strains in 3 regionally distinct zones (remote, adjacent, and infarct) of myocardium were measured to be -14.65 +/- 1.13, -5.11 +/- 0.60 (P < or = .05), and 0.92 +/- 0.56 (P < or = .05), respectively. The regional end-systolic strain correlated strongly with the abundance of 2 major calcium-handling proteins: sarcoplasmic reticulum Ca2+ adenosine triphosphatase subtype 2a (r2 = 0.68, P < or = .05) and phospholamban (r2 = 0.50, P < or = .05). A lesser degree of correlation was observed between the systolic strain and the abundance of sodium/calcium exchanger type 1 protein (r2 = 0.17, P < or = .05).
  
  
  CONCLUSIONS
  Regional strain differences can be defined in the different myocardial regions during postinfarction cardiac remodeling. These differences in regional strain drive regionally distinct alterations in calcium-handling protein expression.
authors.affiliation: Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Md 21201, USA.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Kilic
authors.forename: Tieluo
authors.initials: T
authors.lastname: Li
authors.forename: Timothy D C
authors.initials: TD
authors.lastname: Nolan
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Nash
authors.forename: Shuying
authors.initials: S
authors.lastname: Li
authors.forename: Deyanira J
authors.initials: DJ
authors.lastname: Prastein
authors.forename: Gary
authors.initials: G
authors.lastname: Schwartzbauer
authors.forename: Sina L
authors.initials: SL
authors.lastname: Moainie
authors.forename: G Kwame
authors.initials: GK
authors.lastname: Yankey
authors.forename: Christopher
authors.initials: C
authors.lastname: DeFilippi
authors.forename: Zhongjun
authors.initials: Z
authors.lastname: Wu
authors.forename: Bartley P
authors.initials: BP
authors.lastname: Griffith
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000378:metabolism* / Q000503:physiopathology*; D012756:Sheep; D020257:Ventricular Remodeling
chemical_list: D002135:Calcium-Binding Proteins