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TELECONFRENCES
2004
The Changing Left Ventricle

2003
Aortic Valve Disease: New Dimensions in Evaluation and Management

2002
Heart Failure: Echo's Role in and Emerging Health Crisis

2001
Chest Pain in Children & Adults: The Role of Echo

2000
Mitral Regurgitation: New Concept

1998
The Falling Left Ventricle: Diastolic & Systolic Function

1997
Changing the Outcome of Coronary Artery Disease
ECHO GRAND ROUNDS
Digital Integration
LEARN THE BASICS
Echocardiography
Doppler Echo
VIDEO ARCHIVES

Chest Pain in Children and Adults

Mitral Regurgitation: New Concepts

Diastolic and Systolic Function

Changing the Outcome of CAD

BROADCAST SUPPLEMENTS
2000 MV
2001 Chest Pain
2002 Heart Failure


The Use of the Doppler Controls
Apical Window

For routine Doppler examination of patients with suspected valvular heart disease, it is usually best to begin by using the apical window. This allows selective orientation of the Doppler beam as parallel as possible to the direction of assumed flow through the mitral and tricuspid valves. It also allows the largest Doppler shift to be recorded and the strongest signals to be reflected back to the Doppler transducer.

Fig.1.42

The imaging mode of the system may be used to acquire an apical four-chamber view as seen schematically in Figure 1.42. The PW Doppler sample volume can then be positioned on the atrial or ventricular sides of the mitral or tricuspid valves. The right panel of Figure 1.42 shows schematic representations of the normal spectral outputs through the mitral (sample site 3) and tricuspid valves (sample site 1).

In most normal individuals, whether the sample volume is on the atrial or ventricular sides of the mitral and tricuspid valves results in spectral flow outputs that are quite similar. In the presence of valvular disease, however, markedly different flow patterns are encountered depending upon sample volume position.

When in the apical four chamber view, slight superior angulation of the scan plane will allow the operator to encounter the left ventricular outflow tract. An operator can almost always obtain Doppler flow data from the ventricular side of the aortic valve. In some patients data may also be obtained from the aortic root side. A complete PW Doppler evaluation would continue with movement of the sample volume from place to place in the standard, and then intermediate points.

Continued practice repositioning the PW cursor and sample volume in the various portions of the cardiac chambers accessible from the apical four chamber view will eventually provide the novice operator with an appreciation of the spatial locations and directions of normal and abnormal flows. The heart chambers are actually three dimensional structures and an abnormal flow jet may be directed anywhere within this three dimensions. An experienced operator will be able to track an abnormal jet even if it is directed out of a standard two-dimensional plane.

The apical window is also an excellent position for obtaining some initial experience with continuous wave Doppler. Placing the CW transducer directly over the apical impulse (located by palpation) and angling the beam somewhat leftward and posteriorly will usually result in a typical mitral flow profile. It is wise for the beginner to practice locating flow through the mitral valve as the flow profile resembles the appearance of the mitral valve on M-mode and is readily recognized. Marked medial redirection of the CW beam from the apex will result in a flow profile through the tricuspid valve. Because pressures are higher on the left side of the heart, velocities are generally higher on the left when compared to the right in normal and diseased states. Exceptions to this rule are encountered in severe pulmonary hypertension or stenosis.

Fig.1.43

The ranges of normal peak flow velocities are shown in Figure 1.43. Notice that the normal flows are slightly higher in children than adults and slightly higher on the left side of the heart in comparison to the right.

After some experience, an operator can become very skillful with minor manipulation of the CW transducer.

 

Fig.1.44

The difference between the various waveforms obtained from the ventricular apex using a CW transducer is shown in Figure 1.44. At first, the beam is directed superiorly to encounter aortic insufficiency and stenosis (Figure 1.44 panel A). The insufficiency is directed toward the transducer and appears on the spectral display in diastole. The aortic stenosis flow moves away from the transducer in systole. The CW is then angled midway between ventricular outflow and inflow (Figure 1.44 panel B) and encounters a mixed diastolic profile with mitral inflow superimposed on the aortic insufficiency. Progressive angulation through the mitral valve demonstrates a pure mitral inflow in diastole with mitral insufficiency in systole (Figure 1.44 panel C).

The problem of recording flow across mitral and aortic valve simultaneously (Figure 1.44 panel B). results partly from the fact that the ultrasound beam width is large enough to detect more than one jet. Failure to appreciate this may lead the unwary beginner to diagnose mitral stenosis, for example, when only aortic regurgitation is present.>

Fig.1.45

The apical window also supplies an opportunity for examination of left sided flow with PW Doppler echocardiography by movement of the imaging plane to the apical two-chamber view (Fig. 1.45). This view is obtained by rotating the two-dimensional transducer counterclockwise and 90 degrees from the apical four chamber view and is particularly suited for examination of both left ventricular inflow (Fig. 1.45, sample sites 1 and 2) and outflow (sample sites 3 and 4). Flow velocity profiles through the mitral valve resemble those obtained in the apical four-chamber view and are directed toward the transducer in diastole. It is a little easier to position and hold the pulsed sample volume on the aortic side of the aortic valve using the two-chamber approach rather than the four-chamber with extreme superior angulation.

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