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Ventricular elastance

S100A4 Overexpression Enhanced tumour development and metastasis Increased right ventricular systolic pressure, right ventricular hypertrophy, reduced ventricular elastance and decreased cardiac output. [Pg.101]

The first case study of this chapter outlines the development of a model of left ventricular pumping. The model is devised from canine experiments and represents the left ventricle as a time, volume, and outflow-dependent pressure generator. In the course of model development, a new analytical method of measuring ventricular elastance emerges, with the potential of clarifying issues with previous elastance measurements. One application is a slight model expansion to study the cardiac pump theory of cardiopulmonary resuscitation (CPR). [Pg.129]

Mechanical performance of the heart, more specifically the left ventricle, is typically characterized by estimates of ventricular elastance. The heart is an elastic bag that stiffens and relaxes with each heartbeat. Elastance is a measure of stiffness, classically defined as the differential relation between pressure and volume ... [Pg.129]

Here, py and Vy denote ventricular pressure and volume, respectively. For any instant in time, ventricular elastance Ey is the differential change in pressure with respect to volume. Mathematically, this relation is clear. Measurement of Ey is much less clear. [Pg.129]

FIGURE 8.2 Time-varying ventricular elastance curves measured using the definition in Equation 8.3. Measured elastance curves are distinctive in shape. (Adapted from Suga, H. and Sagawa, K. 1974. Instantaneous pressure-volume relationship under various end-diastolic volume. Circ Res. 35 117-126.)... [Pg.130]

At/AVy in the second term of the right-hand side is equal to —l/Qy, inverse ejection outflow. Consequently, elastance definitions such as Equation 8.2 and Equation 8.3 are not measures purely of ventricular elastance but also include arterial effects. This may explain why suchmodels have difficulty in accurately predicting flow [8]. Consequently, a new measure of the heart s mechanical properties was developed. [Pg.130]

Since ventricular pressure is now defined as an analytical function (Equation 8.7), ventricular elastance, v) defined in the classical sense as dp /dV, maybe calculated as... [Pg.133]

FIGURE 8.7 Ventricular elastance curves computed using the new analytical function of Equation 8.10. Elastance curves computed in this way are representative of the ventricle s contractile state. [Pg.134]

FIGURE 8.10 Ventricular elastance curves computed using Equation 8.10 without (dashed) and with the ejection effect (solid). [Pg.137]

This ventricle model permits computation of ventricular elastance, and may resolve difficulties with previous time-varying elastance definitions. Work is currently underway to devise a new measure of cardiovascular health using this model. In essence, it is thought that the magnitude of the observed ejection effect for a particular heart should be directly related to its health. [Pg.138]


See other pages where Ventricular elastance is mentioned: [Pg.130]    [Pg.132]    [Pg.133]    [Pg.135]    [Pg.64]    [Pg.65]    [Pg.66]    [Pg.97]    [Pg.133]    [Pg.174]    [Pg.192]    [Pg.139]    [Pg.141]    [Pg.142]    [Pg.144]    [Pg.130]    [Pg.132]    [Pg.133]    [Pg.135]    [Pg.325]   
See also in sourсe #XX -- [ Pg.73 , Pg.97 ]




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