Estimation of instantaneous diastolic transmitral pressure
difference from color doppler m-mode echocardiography.
Greenberg, Neil L., Pieter M. Vandervoort, James D. Thomas.
Cardiovascular Imaging Center, Department of Cardiology, The
Cleveland Clinic Foundation, Cleveland, Ohio and Department of
Biomedical Engineering, The Ohio State University, Columbus, Ohio
APStracts 3:0137H, 1996.
Pulsed and continuous wave Doppler velocity measurements are routinely
used in clinical practice to assess severity of stenotic and
regurgitant valves or estimate intracavitary pressures. However this
method only evaluates the convective component of the pressure
gradient (based on the velocity measurements) and neglects the
contribution of inertial forces which can be important, in particular
for flow across non-stenotic valves. Digital processing of color
Doppler ultrasound data was used to noninvasively estimate both the
convective and inertial components of the transmitral pressure
difference. Simultaneous pressure and velocity measurements were
obtained in six anesthetized open-chested dogs. The instantaneous
diastolic transmitral pressure difference is computed from the M-mode
spatiotemporal velocity distribution using the unsteady flow form of
the Bernoulli equation. The inclusion of the inertial forces
([DpI]max = 0.90+/-0.30 mmHg) in the noninvasive pressure difference
calculation significantly increased the correlation with catheter
-based measurement (r = 0.15+/-0.23 vs. 0.85+/-0.08; p<0.0001) and
also allowed an accurate approximation of the peak early filling
pressure difference ( [DpC+I]max = 0.95[Dpcath]max + 0.07, r = 0.92,
p<0.001, error: C+I ([DpC+I]max - [Dpcath]max) = 0.01+/-0.24 mmHg, N
= 90). Noninvasive estimation of left ventricular filling pressure
differences using this technique will improve the understanding of
diastolic filling and function of the heart.
Received 11 January 1996; accepted in final form 6 March 1996.
APS Manuscript Number H15-6.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 16 April 96