Doppler reconstruction of left ventricular pressure from functional mitral regurgitation: potential importance of varying orifice geometry.

Abstract

plotted against the direct record. The plots confirmed that the reconstructed pressure was always less than directly measured pressure, the relative degree of underestimation falling as the pressure rose. This was not the effect of acceleration, but probably reflects changing geometry of the regurgitant orifice. Conclusion-The continuous wave Doppler trace of functional mitral regurgitation is suitable for studying the timing of overall mechanical events and normalised rates of change of pressure in the left ventricle. Estimates of atrioventricular pressure drop by this method and particularly its absolute rates of change seem to be less reliable. (Br HeartJ 1995;73:53-60) Keywords: mitral regurgitation, Doppler measurement.The time course of left ventricular pressure has long been used to assess left ventricular mechanical activity. In 1921, Wiggers described the phases of a cardiac cycle using the combination of left ventricular and aortic pressure pulses,' and noted that the time course of left ventricular pressure could be affected by activation pattern.23 More recently, the ventricular pressure pulse has been used to time the onset and duration of mechanical systole45 and to assess an entity described as "contractility" from its peak rate of change.

Aspects of Fluid Dynamics Applied to the Larger Arteries

“…In the not so distant past pressure was the only parameter accessible to measurements, but #ow distributions tell us far more about the detail. Therefore, there is a need to link diagnoses based on pressure with the velocity data now available from magnetic resonance imaging (MRI, Section 10) and ultrasound (Xiao et al, 1995). The methods used in Yang's study were related to those used for incompressible #ows in computational #uid dynamics (CFD, Section 9), particularly the pressure correction method (Ferziger & PericH , 1996).…”

“…Moreover, since the relatively low velocities occuring in arteries means that the di!erence between static and total pressure (some 4 mm Hg, or 500 Pa at a steady 1 m s\) is a small proportion of the overall pressure level, errors caused by velocity variations have been neglected. However, interest has recently been shown in the variations of pressure linked to velocity variations (Xiao et al, 1995;Yang et al, 1996) and it is important to be sure about the implications.…”

An Assessment of Left Ventricular Systolic Function with the Use of a Continuous Doppler Imaging in Dogs with Spontaneous Mitral Regurgitation. A Preliminary Study

“…The continuous-wave Doppler trace of functional mitral regurgitation is suitable for studying the timing of overall mechanical events and normalised rates of the pressure changes in the left ventricle but seems to be less reliable for estimating the atrioventricular pressure drop (22). The value of dP/dt obtained in our study is similar to healthy mongrel dogs (4).…”