title: Ultrasound shear wave elasticity imaging quantifies coronary perfusion pressure effect on cardiac compliance.
abstract: Diastolic heart failure (DHF) is a major source of cardiac related morbidity and mortality in the world today. A major contributor to, or indicator of DHF is a change in cardiac compliance. Currently, there is no accepted clinical method to evaluate the compliance of cardiac tissue in diastolic dysfunction. Shear wave elasticity imaging (SWEI) is a novel ultrasound-based elastography technique that provides a measure of tissue stiffness. Coronary perfusion pressure affects cardiac stiffness during diastole; we sought to characterize the relationship between these two parameters using the SWEI technique. In this work, we demonstrate how changes in coronary perfusion pressure are reflected in a local SWEI measurement of stiffness during diastole. Eight Langendorff perfused isolated rabbit hearts were used in this study. Coronary perfusion pressure was changed in a randomized order (0-90 mmHg range) and SWEI measurements were recorded during diastole with each change. Coronary perfusion pressure and the SWEI measurement of stiffness had a positive linear correlation with the 95% confidence interval (CI) for the slope of 0.009-0.011 m/s/mmHg ( R(2) = 0.88 ). Furthermore, shear modulus was linearly correlated to the coronary perfusion pressure with the 95% CI of this slope of 0.035-0.042 kPa/mmHg ( R(2) = 0.83). In conclusion, diastolic SWEI measurements of stiffness can be used to characterize factors affecting cardiac compliance specifically the mechanical interaction (cross-talk) between perfusion pressure in the coronary vasculature and cardiac muscle. This relationship was found to be linear over the range of pressures tested.
authors.forename: Maryam
authors.initials: M
authors.lastname: Vejdani-Jahromi
authors.forename: Matt
authors.initials: M
authors.lastname: Nagle
authors.forename: Gregg E
authors.initials: GE
authors.lastname: Trahey
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Wolf
mesh_terms: D000818:Animals; D004452:Echocardiography / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D006321:Heart / Q000502:physiology*; D054144:Heart Failure, Diastolic / Q000000981:diagnostic imaging; D016014:Linear Models; D015425:Myocardial Reperfusion; D011817:Rabbits