title: The myocardial performance index during low-dose dobutamine echocardiography in control subjects and patients with a recent myocardial infarction: a new index of left ventricular functional reserve?
abstract: BACKGROUND
  Wall-motion analysis during low-dose dobutamine echocardiography (LDDE) is a semiquantitative measure of left ventricular contractile reserve after myocardial infarction (MI). The Doppler echocardiographic myocardial performance index (MPI) is a quantitative measure of combined left ventricular systolic and diastolic function. We sought to characterize the changes in MPI during LDDE in control subjects and patients with MI, and to describe the relation of these changes to changes in regional systolic function.
  
  
  METHODS
  MPI was obtained at rest and during LDDE (10 microg/kg/min) in 25 healthy volunteers (group 1) and 50 patients with a recent MI. Patients were divided into two subsets; those with (n = 23; group 2A) and those without (n = 27; group 2B) a contractile reserve defined as an improvement of wall motion in more than two contiguous infarct-zone segments during LDDE. DeltaMPI was defined as the change from rest to LDDE.
  
  
  RESULTS
  MPI decreased significantly during LDDE in groups 1 and 2A, whereas MPI increased in group 2B (DeltaMPI = 0.12 +/- 0.04 and 0.10 +/- 0.08 vs -0.03 +/- 0.08, P <.0001). On multivariate analysis, Deltawall-motion score index predicted DeltaMPI (beta = 0.65, P <.0001) independently of age, sex, and the dobutamine-induced change in heart rate and systolic blood pressure.
  
  
  CONCLUSIONS
  Data suggest that the change in MPI during LDDE may provide a simple and quantitative measure of overall left ventricular functional reserve in patients with a recent MI.
authors.affiliation: Department of Medical Research, Svenborg Hospital, Svenborg, Denmark. betn@shf.fyns-amt.dk
authors.forename: Betina
authors.initials: B
authors.lastname: Nørager
authors.forename: Mirza
authors.initials: M
authors.lastname: Husic
authors.forename: Jacob E
authors.initials: JE
authors.lastname: Møller
authors.forename: Kenneth
authors.initials: K
authors.lastname: Egstrup
mesh_terms: D000368:Aged; D004280:Dobutamine; D015150:Echocardiography, Doppler / Q000379:methods*; D025401:Echocardiography, Stress / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009200:Myocardial Contraction / Q000502:physiology; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015203:Reproducibility of Results; D016277:Ventricular Function, Left / Q000502:physiology*
chemical_list: D004280:Dobutamine