title: Impact of myocardial structure and function postinfarction on diastolic strain measurements: implications for assessment of myocardial viability.
abstract: We sought to assess the role of regional diastolic function by Doppler echocardiography in predicting myocardial viability. Sixteen dogs underwent left anterior descending coronary artery (n = 8) or circumflex (n = 8) occlusion. All animals were imaged at baseline and 1-8 wk postinfarction (post-MI). In 10 dogs, invasive hemodynamic monitoring with a conductance catheter placed in the left ventricle (LV) was performed at the above time points. Dobutamine was infused at 1-8 wk post-MI to determine LV contractile reserve. Histomorphological analysis was performed to determine the presence of viable myocardium and changes in interstitial matrix. Post-MI, diastolic strain rate measurements (in radial and longitudinal planes) decreased significantly in the distribution of the diseased artery (P < 0.01) and on multiple regression analysis were determined by time constant of LV relaxation, end-diastolic pressure, regional stiffness, and the ratio of cellular infiltration to collagen deposition in the interstitial matrix. Among several indexes, diastolic strain rate during dobutamine infusion readily identified segments with >20% transmural infarction and related best to the extent of interstitial fibrosis (r = -0.86, P < 0.01). In an animal model of healing canine infarcts, diastolic strain rate by Doppler echocardiography appears to be a promising novel index of myocardial viability.
authors.affiliation: Section of Cardiology, Department of Medicine, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Tae-Ho
authors.initials: TH
authors.lastname: Park
authors.forename: Sherif F
authors.initials: SF
authors.lastname: Nagueh
authors.forename: Dirar S
authors.initials: DS
authors.lastname: Khoury
authors.forename: Helen A
authors.initials: HA
authors.lastname: Kopelen
authors.forename: Spyridon
authors.initials: S
authors.lastname: Akrivakis
authors.forename: Kamal
authors.initials: K
authors.lastname: Nasser
authors.forename: Guofeng
authors.initials: G
authors.lastname: Ren
authors.forename: Nikolaos G
authors.initials: NG
authors.lastname: Frangogiannis
mesh_terms: D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology; D003971:Diastole; D004280:Dobutamine / Q000494:pharmacology; D004285:Dogs; D004452:Echocardiography; D005260:Female; D006321:Heart / Q000187:drug effects / Q000503:physiopathology*; D006439:Hemodynamics; D008297:Male; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D009206:Myocardium / Q000473:pathology; D013314:Stress, Mechanical; D013599:Systole; D013997:Time Factors; D014022:Tissue Survival
chemical_list: D002316:Cardiotonic Agents; D004280:Dobutamine