Evaluation of model-based processing algorithms for averaged transmitral spectral Doppler images

Hall, A.F.; Nudelman, Scott P.; Kovács, Sándor J.

doi:10.1016/s0301-5629(97)00232-9

Cited by 9 publications

(7 citation statements)

References 15 publications

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“…1). We also previously showed that averaging of parameters from individual images is superior to averaging of images, with an average variation of Ͻ10% for all parameters (8,9). Accordingly, individual beats were selected from the original transmitral digital Doppler image data set.…”

Section: Left Ventricular K LVmentioning

confidence: 99%

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Chamber properties from transmitral flow: prediction of average and passive left ventricular diastolic stiffness

Lisauskas

Singh

Bowman

et al. 2001

Journal of Applied Physiology

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104

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A chamber stiffness (K(LV))-transmitral flow (E-wave) deceleration time relation has been invasively validated in dogs with the use of average stiffness [(DeltaP/DeltaV)(avg)]. K(LV) is equivalent to k(E), the (E-wave) stiffness of the parameterized diastolic filling model. Prediction and validation of 1) (DeltaP/DeltaV)(avg) in terms of k(E), 2) early rapid-filling stiffness [(DeltaP/DeltaV)(E)] in terms of k(E), and 3) passive (postdiastasis) chamber stiffness [(DeltaP/DeltaV)(PD)] from A waves in terms of the stiffness parameter for the Doppler A wave (k(A)) have not been achieved. Simultaneous micromanometric left ventricular (LV) pressure (LVP) and transmitral flow from 131 subjects were analyzed. (DeltaP)(avg) and (DeltaV)(avg) utilized the minimum LVP-LV end-diastolic pressure interval. (DeltaP/DeltaV)(E) utilized DeltaP and DeltaV from minimum LVP to E-wave termination. (DeltaP/DeltaV)(PD) utilized atrial systolic DeltaP and DeltaV. E- and A-wave analysis generated k(E) and k(A). For all subjects, noninvasive-invasive relations yielded the following equations: k(E) = 1,401. (DeltaP/DeltaV)(avg) + 59.2 (r = 0.84) and k(E) = 229.0. (DeltaP/DeltaV)(E) + 112 (r = 0.80). For subjects with diastasis (n = 113), k(A) = 1,640. (DeltaP/DeltaV)(PD) - 8.40 (r = 0.89). As predicted, k(A) showed excellent correlation with (DeltaP/DeltaV)(PD); k(E) correlated highly with (DeltaP/DeltaV)(avg). In vivo validation of average, early, and passive chamber stiffness facilitates quantitative, noninvasive diastolic function assessment from transmitral flow.

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Section: Left Ventricular K LVmentioning

confidence: 99%

“…Accordingly, individual beats were selected from the original transmitral digital Doppler image data set. To account for beat-to-beat variability, at least five beats per subject underwent MBIP, and the resulting parameters were averaged (8,9).…”

Section: Left Ventricular K LVmentioning

confidence: 99%

Chamber properties from transmitral flow: prediction of average and passive left ventricular diastolic stiffness

Lisauskas

Singh

Bowman

et al. 2001

Journal of Applied Physiology

Self Cite

104

View full text Add to dashboard Cite

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“…Analysis of transmitral flow contours (Doppler E-waves) via the PDF formalism (Hall et al 1994a,Hall et al 1994b,Hall et al 1998,Kovács et al 1987,Kovács et al 2000,Lakshminarayan et al 1993 has shown that diabetes alters the relaxation parameter c of early rapid filling in both rats (Dent et al 2001) and humans (Riordan et al 2005). Importantly, these two studies showed that for hearts with normal LVEF, conventional E-wave indexes such as peak E-wave velocity (E peak ) or deceleration time (DT) were unable to differentiate between normal and diabetic filling patterns, whereas the relaxation/viscosity parameter c differentiated between normal (lower c) and diabetic subjects (higher c).…”

Section: Introductionmentioning

confidence: 99%

The Kinematic Filling Efficiency Index of the Left Ventricle: Contrasting Normal vs. Diabetic Physiology

Zhang

Chung

Riordan

et al. 2007

Ultrasound in Medicine & Biology

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An index of filling efficiency incorporating stiffness and relaxation (S&R) parameters has not been derived or validated although numerous studies have focused on the effects of altered relaxation or stiffness on early rapid filling and diastolic function. Previous studies show that S&R parameters can be obtained from early rapid filling (Doppler E-wave) via kinematic modeling. E-wave contours are governed by harmonic oscillatory motion, modeled via the parameterized diastolic filling (PDF) formalism. The previously validated model determines three (unique) oscillator parameters from each E-wave having established physiologic analogues: x o (load), c (relaxation/viscoelasticity), and k (chamber stiffness). We define the dimensionless, filling-volume based kinematic filling efficiency index (KFEI) as the ratio of the velocity-time integral (VTI) of the actual clinical E-wave contour fit via PDF to the VTI of the PDF model-predicted ideal E-wave contour having the same x o and k, but with no resistance to filling (c=0). To validate the new index, Doppler E-waves from 36 subjects with normal ventricular function, 17 diabetic and 19 well-matched non-diabetic controls, were analyzed. E-wave parameters x o , c, and k and KFEI were computed for each subject and compared. In concordance with prior human and animal studies in which c differentiated between normal and diabetic hearts, KFEI differentiated (p<0.001) between non-diabetics (55.8±3.3%) and diabetics (49.1±3.3%). Thus, the new index introduces and validates the concept of filling efficiency, and using diabetes as a working example, provides quantitative and mechanistic insight into how S&R affects ventricular filling efficiency.

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“…Previous work has explored the dependence of these model parameters on a variety of potentially confounding factors, including noise, waveform shape, beat variation, and ultrasound machine specifications (Hall 1997; Hall 1998). The results have consistently supported the robustness of the model-based fitting approach.…”

Section: Discussionmentioning

confidence: 99%

The Diastolic Function to Cyclic Variation of Myocardial Ultrasonic Backscatter Relation: The Influence of Parametrized Diastolic Filling (PDF) Formalism Determined Chamber Properties

Lloyd¹,

Shmuylovich²,

Holland³

et al. 2011

Ultrasound in Medicine & Biology

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Myocardial tissue characterization represents an extension of currently available echocardiographic imaging. The systematic variation of backscattered energy during the cardiac cycle (the “cyclic variation” of backscatter) has been employed to characterize cardiac function in a wide range of investigations. However, the mechanisms responsible for observed cyclic variation remain incompletely understood. As a step toward determining the features of cardiac structure and function that are responsible for the observed cyclic variation, the present study makes use of a kinematic approach of diastolic function quantitation to identify diastolic function determinants that influence the magnitude and timing of cyclic variation. Echocardiographic measurements of 32 subjects provided data for determination of the cyclic variation of backscatter to diastolic function relation characterized in terms of E-wave determined, kinematic model-based parameters of chamber stiffness, viscosity/relaxation, and load. The normalized time delay of cyclic variation appears to be related to the relative viscoelasticity of the chamber and predictive of the kinematic filling dynamics as determined using the parametrized diastolic filling formalism (with r-values ranging from .44 to .59). The magnitude of cyclic variation does not appear to be strongly related to the kinematic parameters.

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Evaluation of model-based processing algorithms for averaged transmitral spectral Doppler images

Cited by 9 publications

References 15 publications

Chamber properties from transmitral flow: prediction of average and passive left ventricular diastolic stiffness

Chamber properties from transmitral flow: prediction of average and passive left ventricular diastolic stiffness

The Kinematic Filling Efficiency Index of the Left Ventricle: Contrasting Normal vs. Diabetic Physiology

The Diastolic Function to Cyclic Variation of Myocardial Ultrasonic Backscatter Relation: The Influence of Parametrized Diastolic Filling (PDF) Formalism Determined Chamber Properties

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