Relationship Between Early Diastolic Intraventricular Pressure Gradients, an Index of Elastic Recoil, and Improvements in Systolic and Diastolic Function

Firstenberg, Michael S.; Smedira, Nicholas G.; Greenberg, Neil L.; Prior, David; McCarthy, Patrick M.; García, Mario J.; Thomas, James D.

doi:10.1161/hc37t1.094834

“…It reaches a maximal peak at the end-systole. This observation was consistent with the P-V diagram of Suga and Sagawa [1] and the other models that described LV stiffness based on P-V relationship [7][8][9][10][11].…”

Section: Discussionsupporting

confidence: 92%

Estimation of elastic and viscous properties of the left ventricle based on annulus plane harmonic behavior

Kheradvar

¹

,

Milano

²

,

Gorman

³

et al. 2006

2006 International Conference of the IEEE Engineering in Medicine and Biology Society

1

0

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Abstract-Assessment of left ventricular (LV) functionwith an emphasis on contractility has been a challenge in cardiac mechanics during the recent decades. The LV function is usually described by the LV pressurevolume (P-V) diagram. The standard P-V diagrams are easy to interpret but difficult to obtain and require invasive instrumentation for measuring the corresponding volume and pressure data. In the present study, we introduce a technique that can estimate the viscoelastic properties of the LV based on harmonic behavior of the ventricular chamber and it can be applied non-invasively as well. The estimation technique is based on modeling the actual long axis displacement of the mitral annulus plane toward the cardiac base as a linear damped oscillator with time-varying coefficients. The time-varying parameters of the model were estimated by a standard Recursive Linear Least Squares (RLLS) technique. LV stiffness at end-systole and end diastole was in the range of 61.86-136.00 dyne/g.cm and 1.25-21.02 dyne/g.cm, respectively. The only input used in this model was the long axis displacement of the annulus plane, which can also be obtained non-invasively using tissue Doppler or MR imaging.

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“…It reaches a maximal peak at the end-systole. This observation was consistent with the P-V diagram of Suga and Sagawa [1] and the other models that described LV stiffness based on P-V relationship [7][8][9][10][11].…”

Section: Discussionsupporting

confidence: 91%

Estimation of elastic and viscous properties of the left ventricle based on annulus plane harmonic behavior

Kheradvar

¹

,

Milano

²

,

Gorman

³

et al. 2006

2006 International Conference of the IEEE Engineering in Medicine and Biology Society

View full text Add to dashboard Cite

Abstract-Assessment of left ventricular (LV) functionwith an emphasis on contractility has been a challenge in cardiac mechanics during the recent decades. The LV function is usually described by the LV pressurevolume (P-V) diagram. The standard P-V diagrams are easy to interpret but difficult to obtain and require invasive instrumentation for measuring the corresponding volume and pressure data. In the present study, we introduce a technique that can estimate the viscoelastic properties of the LV based on harmonic behavior of the ventricular chamber and it can be applied non-invasively as well. The estimation technique is based on modeling the actual long axis displacement of the mitral annulus plane toward the cardiac base as a linear damped oscillator with time-varying coefficients. The time-varying parameters of the model were estimated by a standard Recursive Linear Least Squares (RLLS) technique. LV stiffness at end-systole and end diastole was in the range of 61.86-136.00 dyne/g.cm and 1.25-21.02 dyne/g.cm, respectively. The only input used in this model was the long axis displacement of the annulus plane, which can also be obtained non-invasively using tissue Doppler or MR imaging.

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“…Pooled data from six dogs at four different levels of P LVED (10,15,20, and 25 mmHg) are shown in Table 1. P LA was elevated (P Ͻ 0.001) in parallel with the increase in P LVED .…”

Section: Resultsmentioning

confidence: 99%

“…We are simply exploring the use of WIA to separate the measured pressure and velocity waveforms into their forward and backward components with no presumptions about the origins of these waves. A number of models of LV filling have been suggested, ranging from one-dimensional parametric models (6,15,46) through twodimensional models (49) to fully three-dimensional models (32). All of these models require prior knowledge about the properties and state of the ventricle to enable the prediction, to different levels of complexity, of the mitral filling pattern.…”

Section: Discussionmentioning

confidence: 99%

Assessment of left ventricular diastolic suction in dogs using wave-intensity analysis

Wang¹,

Jalali²,

Sun³

et al. 2005

American Journal of Physiology-Heart and Circulatory Physiology

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. Assessment of left ventricular diastolic suction in dogs using wave-intensity analysis. Am J Physiol Heart Circ Physiol 288: H1641-H1651, 2005. First published November 24, 2004 doi:10.1152/ajpheart.00181.2004.-Two apparently different types of mechanisms have emerged to explain diastolic suction (DS), that property of the left ventricle (LV) that tends to cause it to refill itself during early diastole independent of any force from the left atrium (LA). By means of the first mechanism, DS depends on decreased elastance [e.g., the relaxation time constant ()] and, by the second, end-systolic volume (VLVES). We used waveintensity analysis (WIA) to measure the total energy transported by the backward expansion wave (IWϪ) during LV relaxation in an attempt to reconcile these mechanisms. In six anesthetized, open-chest dogs, we measured aortic, LV (PLV), LA (PLA), and pericardial pressures and LV volume by orthogonal ultrasonic crystals. Mitral velocity was measured by Doppler echocardiography, and aortic velocity was measured by an ultrasonic flow probe. Heart rate was controlled by pacing, VLVES by volume loading, and by isoproterenol or esmolol administration. IWϪ was found to be inversely related to and VLVES. Our measure of DS, the energy remaining after mitral valve opening, IWϪDS, was also found to be inversely related to and VLVES and was ϳ10% of the total "aspirating" energy generated by LV relaxation (i.e., I WϪ). The size of the Doppler (early filling) E wave depended on IWϪDS in addition to IWϩ, the energy associated with LA decompression. We conclude that the energy of the backward-going wave generated by the LV during relaxation depends on both the rate at which elastance decreases (i.e., ) and V LVES. WIA provides a new approach for assessing DS and reconciles those two previously proposed mechanisms. The E wave depends on DS in addition to LA decompression. diastole; hemodynamics; mitral valve; ventricles DIASTOLIC SUCTION (DS) is defined as that property of the left ventricle (LV) that tends to cause it to refill itself during early diastole independent of any force from the left atrium (LA). Two apparently different types of mechanistic explanations have emerged. The first type is represented by Katz (30) and Wiggers (52), who related DS to the decrease in ventricular elastance, and by several contemporary investigators (11,12,38,47) who emphasized the importance of the rate of LV relaxation in subsequent diastolic filling. In 1957, Wiggers wrote that "During early moments of ventricular relaxation, elastic stresses created during contraction are released. . . If blood could enter the ventricular chamber during this phase of diastole, such a rapid drop in pressure would unquestionably constitute a potent aspirating force" (52).Wiggers implied that the relaxing LV generates an "aspirating force" from the moment LV pressure begins to decrease. Accordingly, as elaborated upon below, the first effect of a relaxation-generated aspirating force must be to decelerate the mass represented by the stroke v...

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Relationship Between Early Diastolic Intraventricular Pressure Gradients, an Index of Elastic Recoil, and Improvements in Systolic and Diastolic Function

Abstract: Background-Early diastolic intraventricular pressure gradients (IVPGs)

Cited by 104 publications

References 22 publications

Estimation of elastic and viscous properties of the left ventricle based on annulus plane harmonic behavior

Estimation of elastic and viscous properties of the left ventricle based on annulus plane harmonic behavior

Estimation of elastic and viscous properties of the left ventricle based on annulus plane harmonic behavior

Assessment of left ventricular diastolic suction in dogs using wave-intensity analysis

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