文档介绍：PRINCIPLES OF DOPPLER ECHOCARDIOGRAPHY
AND THE DOPPLER EXAMINATION #1
Joseph A. Kisslo, MD
David B. Adams, RDCS
INTRODUCTION
Doppler echocardiography is a method for detecting the direction and velocity of moving blood
within the heart. As will be seen in this program, the technique may be used for detection of
cardiac valvular insufficiency and stenosis as well as a large number of other abnormal flows. The
current interest in Doppler echocardiography has reached a remarkable level in just the past few
years. Doppler methods extend the use of cardiac ultrasound into the evaluation of normal and
abnormal flow states and provide quantitative data that are essential in the clinical decision making
process concerning patients with heart disease.
Understanding Doppler echocardiography
begins with an understanding of the Doppler
principle. All readers are familiar with the
Doppler effect in every day life. For example,
an observer stationed on a highway overpass
readily notices that the pitch of the sound made
from the engine of a passing automobile
changes from high to low as the car approaches
and then travels into the distance. The engine
is emitting the same sound as it passes beneath,
but the observer notices a change in pitch
dependent upon the speed of the auto and its
direction. Figure demonstrates the
Figure : An example of the Doppler effect in every changes in the frequency from an approaching
day life: the sound emitted from a stationary and and departing sound source (the moving
moving automobile engine. automobile) relative to a stationary sound
source.
The first description of the physical principles used in Doppler echocardiography is attributed to
Johann Christian Doppler, an Austrian mathematician and scientist who lived in the first half of the
19th century. Doppler’s initial descriptions referred to changes in the wavelength of light as
applied to