title: Impact of thoracic surgery on cardiac morphology and function in small animal models of heart disease: a cardiac MRI study in rats.
abstract: BACKGROUND
  Surgical procedures in small animal models of heart disease might evoke alterations in cardiac morphology and function. The aim of this study was to reveal and quantify such potential artificial early or long term effects in vivo, which might account for a significant bias in basic cardiovascular research, and, therefore, could potentially question the meaning of respective studies.
  
  
  METHODS
  Female Wistar rats (n = 6 per group) were matched for weight and assorted for sham left coronary artery ligation or control. Cardiac morphology and function was then investigated in vivo by cine magnetic resonance imaging at 7 Tesla 1 and 8 weeks after the surgical procedure. The time course of metabolic and inflammatory blood parameters was determined in addition.
  
  
  RESULTS
  Compared to healthy controls, rats after sham surgery showed a lower body weight both 1 week (267.5±10.6 vs. 317.0±11.3 g, n<0.05) and 8 weeks (317.0±21.1 vs. 358.7±22.4 g, n<0.05) after the intervention. Left and right ventricular morphology and function were not different in absolute measures in both groups 1 week after surgery. However, there was a confined difference in several cardiac parameters normalized to the body weight (bw), such as myocardial mass (2.19±0.30/0.83±0.13 vs. 1.85±0.22/0.70±0.07 mg left/right per g bw, p<0.05), or enddiastolic ventricular volume (1.31±0.36/1.21±0.31 vs. 1.14±0.20/1.07±0.17 µl left/right per g bw, p<0.05). Vice versa, after 8 weeks, cardiac masses, volumes, and output showed a trend for lower values in sham operated rats compared to controls in absolute measures (782.2±57.2/260.2±33.2 vs. 805.9±84.8/310.4±48.5 mg, p<0.05 for left/right ventricular mass), but not normalized to body weight. Matching these findings, blood testing revealed only minor inflammatory but prolonged metabolic changes after surgery not related to cardiac disease.
  
  
  CONCLUSIONS
  Cardio-thoracic surgical procedures in experimental myocardial infarction cause distinct alterations upon the global integrity of the organism, which in the long term also induce circumscribed repercussions on cardiac morphology and function. This impact has to be considered when analyzing data from respective animal studies and transferring these findings to conditions in patients.
authors.affiliation: Department of Internal Medicine I - Cardiology, University Hospital Würzburg, Würzburg, Germany ; Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Nordbeck
authors.forename: Leoni
authors.initials: L
authors.lastname: Bönhof
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Hiller
authors.forename: Sabine
authors.initials: S
authors.lastname: Voll
authors.forename: Paula
authors.initials: P
authors.lastname: Arias-Loza
authors.forename: Lea
authors.initials: L
authors.lastname: Seidlmayer
authors.forename: Tatjana
authors.initials: T
authors.lastname: Williams
authors.forename: Yu-Xiang
authors.initials: YX
authors.lastname: Ye
authors.forename: Daniel
authors.initials: D
authors.lastname: Gensler
authors.forename: Theo
authors.initials: T
authors.lastname: Pelzer
authors.forename: Georg
authors.initials: G
authors.lastname: Ertl
authors.forename: Peter M
authors.initials: PM
authors.lastname: Jakob
authors.forename: Wolfgang R
authors.initials: WR
authors.lastname: Bauer
authors.forename: Oliver
authors.initials: O
authors.lastname: Ritter
mesh_terms: D000818:Animals; D001835:Body Weight; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D004195:Disease Models, Animal; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006331:Heart Diseases / Q000601:surgery*; D006352:Heart Ventricles / Q000503:physiopathology; D007249:Inflammation; D008279:Magnetic Resonance Imaging; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods; D009203:Myocardial Infarction / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar