title: Tissue Doppler imaging detects early asymptomatic myocardial abnormalities in a dog model of Duchenne's cardiomyopathy.
abstract: OBJECTIVE
  Early diagnosis of Duchenne's dilated cardiomyopathy remains a challenge for conventional echocardiography. We sought to determine whether tissue Doppler imaging (TDI) could detect early alteration in myocardial function in a dog model of Duchenne muscular dystrophy, i.e. the Golden Retriever Muscular Dystrophy (GRMD).
  
  
  RESULTS
  Myocardial function was assessed by TDI in 20 dogs with normal conventional parameters of systolic function (eight controls and 12 GRMD, 25+/-11 weeks) without knowledge of the genotype. M-mode TDI was recorded from a short-axis view for measurement of endocardial and epicardial velocities and myocardial velocity gradient (MVG) within the posterior wall. Controls and GRMD dogs were comparable regarding left ventricular fractional shortening (37+/-2 vs 42+/-3%, p=ns). Conversely, TDI showed, in all GRMD dogs, a dramatic decrease in systolic MVG (0.8+/-0.1 vs 2.9+/-0.3 s(-1), p<0.0001) and early diastolic MVG (2.3+/-2.2 vs 10.8+/-1.1 s(-1), p<0.0001). This MVG alteration was related to a significant decrease in endocardial velocities in GRMD whereas epicardial velocities were comparable in the two groups.
  
  
  CONCLUSIONS
  These results show that TDI is more sensitive than conventional echocardiography in detecting pre-clinical myocardial abnormalities before occurrence of left ventricular dilation and dysfunction. TDI should be part of the screening techniques for the early diagnosis of cardiomyopathy.
authors.affiliation: INSERM E0001, Kremlin-Bicêtre, France. vchetboul@vet-alfort.fr
authors.forename: Valérie
authors.initials: V
authors.lastname: Chetboul
authors.forename: Catherine
authors.initials: C
authors.lastname: Escriou
authors.forename: Dominique
authors.initials: D
authors.lastname: Tessier
authors.forename: Vincent
authors.initials: V
authors.lastname: Richard
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Pouchelon
authors.forename: Hélène
authors.initials: H
authors.lastname: Thibault
authors.forename: Françoise
authors.initials: F
authors.lastname: Lallemand
authors.forename: Christian
authors.initials: C
authors.lastname: Thuillez
authors.forename: Stéphane
authors.initials: S
authors.lastname: Blot
authors.forename: Geneviève
authors.initials: G
authors.lastname: Derumeaux
mesh_terms: D000818:Animals; D009202:Cardiomyopathies / Q000000981:diagnostic imaging / Q000473:pathology*; D004285:Dogs; D015150:Echocardiography, Doppler / Q000379:methods; D008297:Male; D008954:Models, Biological; D020388:Muscular Dystrophy, Duchenne / Q000000981:diagnostic imaging / Q000473:pathology*