title: Cardiac characterization of mdx mice using high-resolution doppler echocardiography.
abstract: OBJECTIVE
  Duchenne muscular dystrophy is an X-linked neuromuscular disorder. The heart is traditionally involved, leading to heart failure. The mdx mouse is a natural animal model of the disease. We conducted a prospective study to analyze left ventricular (LV) function in mdx mice at different ages using high-resolution Doppler echocardiography.
  
  
  METHODS
  Echocardiography was performed with a 30-MHz cardiac probe. Wild-type and mdx mice were scanned at 10 and 12 months. We measured the interventricular septal wall thickness, posterior wall thickness, and LV diameter in systole and diastole. The LV shortening fraction, LV ejection fraction, and LV mass were then calculated.
  
  
  RESULTS
  At 10 months, the shortening fractions in mdx and wild-type mice were relatively close (29% ± 5% versus 25% ± 4%). We found a significant difference in the posterior wall thickness change (40% ± 12% in mdx versus 28% ± 10% in wild-type; P = .048). The LV mass/body weight ratio was higher in mdx than wild-type mice (3.67 ± 0.25 versus 3.39 ± 0.26; P = .05). At 12 months, the LV mass was elevated in mdx mice compared to wild-type (152 ±16 versus 135 ± 3.7 mg; P = .04). The diastolic posterior wall thickness change was decreased in mdx mice at 12 months compared to wild-type (21% ± 7% versus 33% ± 4%; P = .01). The LV ejection fraction was not statistically different between mdx and wild-type mice (50% ± 6% versus 54% ± 2%).
  
  
  CONCLUSIONS
  Ten-month-old mdx mice had a significantly higher posterior wall thickness than wild-type mice, but it was not significant at 12 months. In 12-month-old mdx mice, the posterior wall thickness change was significantly lower, and the LV mass was significantly higher. These findings indicate the role of LV function in the early stages of Duchenne muscular dystrophy.
authors.affiliation: Raymond Poincaré Hospital, Assistance Publique Hopitaux de Paris, University of Versailles Saint-Quentin-en-Yvelines, Garches, France. fayssoil2000@yahoo.fr
authors.forename: Abdallah
authors.initials: A
authors.lastname: Fayssoil
authors.forename: Gilles
authors.initials: G
authors.lastname: Renault
authors.forename: Nicolas
authors.initials: N
authors.lastname: Guerchet
authors.forename: Carmen
authors.initials: C
authors.lastname: Marchiol-Fournigault
authors.forename: Françoise
authors.initials: F
authors.lastname: Fougerousse
authors.forename: Isabelle
authors.initials: I
authors.lastname: Richard
mesh_terms: D000465:Algorithms; D000818:Animals; D009202:Cardiomyopathies / Q000000981:diagnostic imaging*; D015150:Echocardiography, Doppler / Q000379:methods*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D020388:Muscular Dystrophy, Duchenne / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left