Could the type of measurement and analysis of arterial wall distensibility
ABT-199 nmr help to define the mainly affected part of arterial wall involved in pathological process? The influence of left ventricle function on a blood pressure could be measured by calculation of total arterial compliance: TAC=SVPPwhere SV is left ventricle stroke volume. Classical compliance is a change in blood volume in response to a given change in expanding pressure: CC=ΔVΔP−volume change to pressure ratioSince the distensibility of arterial wall is mainly blood pressure and volume dependent the systolic and diastolic pressure ratio is included in a most of calculations of vessel’s elastic properties  and . Wall stress can be defined as the difference in systolic and diastolic blood pressure: Pulse pressure (PP)=Ps−PdPulse pressure (PP)=Ps−Pd The stress/strain relationship can be measured as vessel’s diameter
(or area) and pressure compliance given by different equations  and . The most frequently used are: Compliance (C) C=StrainPP Pressure/strain elastic modulus (EM) is calculated as EM=K×Ps−PdStrainwhere K is conversion factor for mmHg to Nm = 133.3. Young KU-57788 price modulus of elasticity (Y) which reflects the stiffness of an isotropic elastic material and can be defined as a ratio of stress to strain per unit area . Y=ΔPΔD⋅DdIMTwhere IMT is intima–media thickness. Stiffness index (β) is calculated as β=lnPsPd⋅Strain Young elastic modulus (EINC) EINC=3(1=LCSA/WCSA)DISTwhere LSCA – luminal cross-sectional area; WSCA – mean wall cross-sectional
area; DIST – cross-sectional distensibility. There are some beliefs that inclusion of different measurements of wall properties as well as hemodynamic parameters in equation could provide more informative and comprehensive index. Like EINC-pressure and EINC-stress curves calculated from IMT and from diameter and pressure waveforms could buy MG-132 provide more precisely direct information about elastic properties of the wall material that is independent of the vessel’s geometry, whereas distensibility gives information on the elastic properties of the artery as a hollow structure . The same could be said about the measure of contribution that the wall reflection makes to systolic arterial pressure. These measurements of reflecting waves coming from periphery to centre are calculated as augmentation pressure (AG) and augmentation index (AI)  and . The disadvantage of above mentioned calculations lies in the comparison of elastic properties of different arteries like the comparison of wall dynamics of carotid artery to changes in blood pressure measured in a brachial artery.