Fig. 9.1 Top: Calcified semilunar cusps in aortic stenosis. Bottom: Pressure overload causes concentric left ventricular hypertrophy.
Fig. 9.2 The parasternal short-axis view is particularly well-suited for visualizing decreased opening motion although separation does not permit estimation of the degree of stenosis.
Fig. 9.3 M-mode recording across the aortic valve shows echodense, bandlike reflections of the calcified valve apparatus with reduced opening motion. Separation cannot be thoroughly displayed and provides no indication of degree of stenosis.
Fig. 9.4 The accelerated outflow across the aortic valve is represented in the continuous-wave (CW) Doppler mode by a V-shaped flow profile with increased velocities. The recorded velocities (preferably including stroke volume) are used for quantification purposes.
Color Doppler Imaging
Fig. 9.5 The stenotic aortic valve causes an increase in flow velocity with corresponding color change above the valve.
Fig. 9.6 Increased outflow across the aortic valve can be readily demonstrated in the apical five-chamber view.
9. 1.2 Medium-Grade Aortic Stenosis
Fig. 9.7 Moderately calcified valves in medium-grade aortic stenosis. The moderately elevated pressure gradient has not caused hypertrophy of the left ventricle.
Fig. 9.8 CW Doppler mode displays a moderate rise in flow velocity up to approximately 3 m/s. Computer-assisted conversion yields a maximum gradient of 36 mmHg.
9. 1.3 High-Grade Aortic Stenosis
Fig. 9.9 Marked calcification of the aortic valve. There is concentric left ventricular hypertrophy.
Fig. 9.10 CW Doppler demonstrating a rise in flow velocity up to 5 m/s, corresponding to a maximum gradient of 100 mmHg. Patience and time are necessary to obtain a usable CW analysis of transaortic flow.
9. 2 Mitral Stenosis
9. 2.1 Mitral Stenosis, General
Fig. 9.11 Top: Calcified mitral valve in mitral stenosis. Bottom: Dilatation of the left atrium and right heart as a result of pressure overload.
Fig. 9.12 In the parasternal short-axis view, the remaining mitral valve orifice area can be seen directly and planimetered using computer analysis. Under good visualization, this value can be used for quantification.
Fig. 9.13 M-mode across the mitral valve shows decreased opening motion of both leaflets. Limited opening motion is not a valid parameter for estimating degree of severity.
Fig. 9.14 Top: CW Doppler recording showing increased transmitral velocity as well as a flat decline in transmitral inflow. Bottom: Computer-assisted measurement of diastolic pressure gradient is used for quantification (so-called pressure half-time).
9. 2.2 Low-Grade Mitral Stenosis
Fig. 9.15 Top: Moderate calcification of the valve leaflets and atrial dilatation. Bottom: The minimal increase in transmitral inflow velocity causes a circumscribed color change.
Fig. 9.16 Top: CW Doppler shows a rapid decline in transmitral inflow. Bottom: Computer-assisted quantification yields a functional valve orifice area of > 2 cm2.
9. 2.3 High-Grade Mitral Stenosis
Fig. 9.17 Marked calcification of the mitral valves as well as a considerably dilated left atrium can be seen. Increased inflow velocity across the stenotic valve appears like a candle flame in the image.
Fig. 9.18 Top: CW Doppler imaging shows a slow decrease in transmitral inflow velocity. Bottom: Analysis of the slope velocity yields a valve orifice area of 1.0 cm2.