title: Analysis of microvascular integrity, contractile reserve, and myocardial viability after acute myocardial infarction by dobutamine echocardiography and myocardial contrast echocardiography.
abstract: The purpose of this study was to evaluate, in postinfarction dysfunctioning myocardium, the relative potential of myocardial contrast and low-dose dobutamine echocardiography in detecting myocardial viability, and the relation between microvascular integrity, contractile reserve, and functional recovery at follow-up. Twenty-four patients with recent myocardial infarction were studied before hospital discharge with low-dose dobutamine and myocardial contrast echocardiography. In the dysfunctioning infarct area, wall motion score index was calculated at baseline, during low-dose dobutamine, and at 3-month follow-up. Revascularization of the infarct-related artery was performed if clinically indicated. Eighteen patients (group A) had myocardial enhancement of the dysfunctioning infarct area at myocardial contrast echocardiography of >50%, whereas the remaining patients (group B) had an increase of < or = 50%. Wall motion score index was similar at baseline in groups A and B (2.6 +/- 0.4 and 2.8 +/- 0.2; p = NS), but it improved during low-dose dobutamine and at follow-up only in group A (1.9 +/- 0.9 and 1.9 +/- 0.7, respectively; p <0.001 vs baseline). In group B, wall motion score index was 2.7 +/- 0.4 with low-dose dobutamine and 2.8 +/- 0.2 at follow-up (p = NS vs rest). In identifying viable myocardial segments, myocardial contrast echo had 100% sensitivity and 46% specificity, whereas low-dose dobutamine echo had 71% sensitivity and 88% specificity. Thus, microvascular integrity after acute myocardial infarction is a fundamental prerequisite for ensuring myocardial contractile reserve and regional functional recovery. Myocardial contrast and low-dose dobutamine echocardiography have different, but complementary, diagnostic characteristics in detecting myocardial viability.
authors.affiliation: The Institute of Cardiology, University of Bari, Bari, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Iliceto
authors.forename: L
authors.initials: L
authors.lastname: Galiuto
authors.forename: A
authors.initials: A
authors.lastname: Marchese
authors.forename: D
authors.initials: D
authors.lastname: Cavallari
authors.forename: P
authors.initials: P
authors.lastname: Colonna
authors.forename: G
authors.initials: G
authors.lastname: Biasco
authors.forename: P
authors.initials: P
authors.lastname: Rizzon
mesh_terms: D000368:Aged; D002316:Cardiotonic Agents; D015986:Confounding Factors, Epidemiologic; D003326:Coronary Circulation / Q000187:drug effects; D004280:Dobutamine; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006321:Heart / Q000187:drug effects / Q000503:physiopathology*; D006801:Humans; D016014:Linear Models; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
chemical_list: D002316:Cardiotonic Agents; D004280:Dobutamine