Noninvasive estimation of transmitral pressure drop across the normal mitral valve in humans: importance of convective and inertial forces during left ventricular filling
Michael S. Firstenberg, MDa,
Pieter M. Vandervoort, MDa,
Neil L. Greenberg, PhDa,
Nicholas G. Smedira, MD, FACCb,
Patrick M. McCarthy, MD, FACCb,
Mario J. Garcia, MD, FACCa and
James D. Thomas, MD, FACCa
a Cardiovascular Imaging Center, Department of Cardiology, Cleveland, Ohio, USA
b Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic Foundation, Cleveland, Ohio, USA
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Figure 1 Data acquisition example. A, demonstrates a transesophageal echocardiographic image with the Doppler scanline aligned from the left atrium (LA), across the mitral valve (MV), and into the left ventricle (LV). The color Doppler M-mode image with the left atrium at the top and the left ventricle at the bottom with flow across the mitral valve is shown. The blue color display shows left ventricular filling from the left atrium into the left ventricle. Orange and red colors within the filling wave indicate velocity aliasing. Within the region of interest (white box) separate E-waves (early filling wave) and A-waves (atrial contraction) can be identified. At the top is the electrocardiogram, and at the bottom is the marker signal used for temporal alignment. B, shows the simultaneously acquired LA and LV pressures stored together with the electrocardiogram and the marker signal.
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Figure 2 Data example of the transmitral pressure difference in a representative cardiac cycle. The dashed line represents the invasively measured pressure difference with two positive gradients, one during early diastole and one during atrial contraction, and a mid-diastolic gradient reversal. The reconstructed pressure difference using the simplified Bernoulli equation is displayed in the thin solid line, showing significant underestimation and delay relative to the catheter measurements. Data from the complete Bernoulli equation is represented by the thicker solid line, which tracks the catheter data much more closely.
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Figure 3 Linear regression plot reflecting significant underestimation of peak transmitral pressure drop by the simplified Bernoulli equation (closed circles) with improved accuracy by the complete Bernoulli equation (open circles).
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Figure 4 Bland–Altman plot reflecting significant underestimation of peak transmitral pressure drop by the simplified Bernoulli equation (closed circles) with improved accuracy by the complete Bernoulli equation (open circles).
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