Title :
Determination of early diastolic LV vortex formation time (T∗) via the PDF formalism: A kinematic model of filling
Author :
Ghosh, Erina ; Shmuylovich, Leonid ; Kovács, Sándor J.
Author_Institution :
Dept. of Biomed. Eng., Washington Univ. in St. Louis, St. Louis, WA, USA
Abstract :
The filling (diastolic) function of the human left ventricle is most commonly assessed by echocardiography, a non-invasive imaging modality. To quantify diastolic function (DF) empiric indices are obtained from the features (height, duration, area) of transmitral flow velocity contour, obtained by echocardiography. The parameterized diastolic filling (PDF) formalism is a kinematic model developed by Kovaacutecs et al which incorporates the suction pump attribute of the left ventricle and facilitates DF quantitation by analysis of echocardiographic transmitral flow velocity contours in terms of stiffness (k), relaxation (c) and load (xo). A complementary approach developed by Gharib et al, uses fluid mechanics and characterizes DF in terms of vortex formation time (T*) derived from streamline features formed by the jet of blood aspirated into the ventricle. Both of these methods characterize DF using a causality-based approach. In this paper, we derive T*´s kinematic analogue T*kinematic in terms of k, c and xo. A comparison between T*kinematic and T*fluid mechanic obtained from averaged transmitral velocity and mitral annulus diameter, is presented. We found that T* calculated by the two methods were comparable and T*kinematic correlated with the peak LV recoil driving force kxo.
Keywords :
blood; echocardiography; haemodynamics; haemorheology; vortices; LV recoil driving force; blood jet; causality-based approach; diastolic LV vortex formation time; echocardiography; filling kinematic model; fluid mechanics; human left ventricle; kinematic model; load; mitral annulus diameter; noninvasive imaging modality; parameterized diastolic filling formalism; relaxation; stiffness; suction pump; transmitral flow velocity contour; Algorithms; Biomechanics; Biomedical Engineering; Blood Pressure; Computer Simulation; Diastole; Echocardiography; Heart Ventricles; Humans; Models, Biological; Models, Statistical; Models, Theoretical; Ventricular Dysfunction, Left;
Conference_Titel :
Engineering in Medicine and Biology Society, 2009. EMBC 2009. Annual International Conference of the IEEE
Conference_Location :
Minneapolis, MN
Print_ISBN :
978-1-4244-3296-7
Electronic_ISBN :
1557-170X
DOI :
10.1109/IEMBS.2009.5333111