title: Viscoelastic properties of normal and infarcted myocardium measured by a multifrequency shear wave method: comparison with pressure-segment length method.
abstract: Our aims were (i) to compare in vivo measurements of myocardial elasticity by shear wave dispersion ultrasound vibrometry (SDUV) with those by the conventional pressure-segment length method, and (ii) to quantify changes in myocardial viscoelasticity during systole and diastole after reperfused acute myocardial infarction. The shear elastic modulus (μ1) and viscous coefficient (μ2) of left ventricular myocardium were measured by SDUV in 10 pigs. Young's elastic modulus was independently measured by the pressure-segment length method. Measurements made with the SDUV and pressure-segment length methods were strongly correlated. At reperfusion, μ1 and μ2 in end-diastole were increased. Less consistent changes were found during systole. In all animals, μ1 increased linearly with left ventricular pressure developed during systole. Preliminary results suggest that μ1 is preload dependent. This is the first study to validate in vivo measurements of myocardial elasticity by a shear wave method. In this animal model, the alterations in myocardial viscoelasticity after a myocardial infarction were most consistently detected during diastole.
authors.affiliation: Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA. Electronic address: Pislaru.Cristina@mayo.edu.
authors.forename: Cristina
authors.initials: C
authors.lastname: Pislaru
authors.affiliation: Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Urban
authors.affiliation: Cardiovascular Division, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: Sorin V
authors.initials: SV
authors.lastname: Pislaru
authors.affiliation: Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: Randall R
authors.initials: RR
authors.lastname: Kinnick
authors.affiliation: Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: James F
authors.initials: JF
authors.lastname: Greenleaf
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D055119:Elastic Modulus / Q000502:physiology*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*; D013552:Swine; D014783:Viscosity
keywords: Echocardiography; Elasticity; Elastography; Myocardial infarction; Myocardial stiffness; Shear elasticity; Shear wave; Ultrasound; Viscoelasticity