title: Tissue Doppler imaging differentiates physiological from pathological pressure-overload left ventricular hypertrophy in rats.
abstract: BACKGROUND
  The myocardial velocity gradient (MVG) is a recent index of regional myocardial function derived from endocardial and epicardial velocities obtained by tissue Doppler imaging (TDI). This index might be useful for discriminating between physiological and pathological left ventricular hypertrophy (LVH) and for documenting the early transition from compensated LVH to heart failure. We sought to compare MVG measured across the left ventricular posterior wall between normal rats and rats with physiological (exercise) and pathological (pressure-overload) LVH.
  
  
  RESULTS
  Wistar rats were assigned to one of the following groups: sedentary, exercise (swimming), and 2-month or 9-month abdominal aortic banding. Compared with sedentary rats, exercise and 2-month banding led to similar and significant LVH. After 2-month banding, conventional parameters of systolic function (left ventricular fractional shortening and dP/dt(max)) were not affected. However, systolic and diastolic MVG were similar in exercise and sedentary rats but were significantly lower in rats with aortic banding. Aortic debanding after 2 months led to a full recovery of MVG, whereas MVG remained decreased when debanding was performed after 9 months.
  
  
  CONCLUSIONS
  Myocardial contraction and relaxation assessed by TDI were impaired in pressure-overload LVH but not in exercise LVH. Therefore, TDI is more sensitive than conventional echocardiography for assessing myocardial dysfunction in pressure-overload LVH and for predicting early recovery in myocardial function after loading conditions normalization.
authors.affiliation: INSERM E9920, Rouen University, Rouen, France. Genevieve.Derumeaux@chu-rouen.fr
authors.forename: Geneviève
authors.initials: G
authors.lastname: Derumeaux
authors.forename: Paul
authors.initials: P
authors.lastname: Mulder
authors.forename: Vincent
authors.initials: V
authors.lastname: Richard
authors.forename: Abdeslam
authors.initials: A
authors.lastname: Chagraoui
authors.forename: Catherine
authors.initials: C
authors.lastname: Nafeh
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bauer
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Henry
authors.forename: Christian
authors.initials: C
authors.lastname: Thuillez
mesh_terms: D000818:Animals; D001011:Aorta; D003250:Constriction; D015150:Echocardiography, Doppler / Q000379:methods*; D006321:Heart / Q000503:physiopathology; D006439:Hemodynamics; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D007700:Kinetics; D009924:Organ Culture Techniques; D010805:Physical Conditioning, Animal; D011312:Pressure; D051381:Rats; D017208:Rats, Wistar