title: Feasibility of myocardial performance index for evaluation of left ventricular function during dobutamine stress echocardiography before and after coronary artery bypass grafting.
abstract: OBJECTIVE
  Myocardial performance index (MPI) is a measure of combined systolic and diastolic myocardial function. In patients with coronary artery disease (CAD) an increase in MPI is consistent with myocardial dysfunction. The objectives of this study were to characterize the changes in MPI after coronary artery bypass graft (CABG) at rest and at peak dobutamine stress echocardiography (DSE).
  
  
  RESULTS
  Thirty-six patients diagnosed with CAD and accepted for CABG were studied by standard echocardiography and DSE 1 month prior and 3 month after CABG. The MPI was calculated using pulsed-wave tissue Doppler imaging (PW-TDI) of the left ventricular (LV) wall-motion velocity. At baseline, ejection fraction (EF; 42.7 ± 8%) and wall-motion score index (WMSI; 1.1 ± 0.2) were impaired at rest as well as at peak DSE (EF; 49.2 ± 9 and WMSI 1.4 ± 0.2). MPI was prolonged both at rest (0.61 ± 0.13) and at peak DSE (0.78 ± 0.16). After CABG, EF and WMSI did not improve at rest (43.7 ± 8% and 1.1 ± 0.2, respectively). On the other hand, MPI improved substantially both at rest (0.45 ± 0.08; P < 0.001) and at peak DSE (0.56 ± 0.1; P < 0.001). At peak DSE an improvement of EF (54.2 ± 9; P < 0.05) and WMSI (1.1 ± 0.16; P < 0.001) was seen as well.
  
  
  CONCLUSIONS
  Myocardial performance index shows significant improvement after CABG in patients with CAD both at rest and peak DSE and appears to be a sensitive measure of myocardial function.
authors.affiliation: Department of Clinical Physiology, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors.forename: Nashmil
authors.initials: N
authors.lastname: Hashemi
authors.forename: Bassem A
authors.initials: BA
authors.lastname: Samad
authors.forename: Anders
authors.initials: A
authors.lastname: Hedman
authors.forename: Lars-Åke
authors.initials: LÅ
authors.lastname: Brodin
authors.forename: Mahbubul
authors.initials: M
authors.lastname: Alam
mesh_terms: D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*; D015150:Echocardiography, Doppler / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods; D005080:Exercise Test / Q000379:methods; D005260:Female; D006334:Heart Function Tests / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014665:Vasodilator Agents; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology / Q000517:prevention & control*
chemical_list: D014665:Vasodilator Agents
keywords: coronary artery disease; left ventricular function; myocardial performance index; tissue Doppler imaging