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Basic Echocardiography
Modes and Modalities
©2004 St. Jude Medical CRMD
Echocardiography
• Echocardiography is the application of ultrasound
to evaluate cardiac anatomy and physiology.
• There are several different ways that ultrasound is
used in echocardiography to assess cardiac
structure/function.
• These different ways (or modalities) will be
discussed in the following slides.
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Echocardiography
• The standard/basic modalities that are commonly
used in echo are:
• 2-Dimensional or “real-time” echo
• M-Mode or “motion mode” echo
• Color doppler echo, and
• Spectral doppler echo
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2-Dimensional
Echocardiography
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2-Dimensional Echo
• Ultrasound waves are generated by the transducer and
penetrate into the soft tissue.
• Each tissue density interface within the body reflects
part of the ultrasound wave back to the transducer.
• The ultrasound platform forms an image based upon
the arrival time and intensity of the returned ultrasound
wave.
• In 2 dimensional echocardiography, each image is
formed from a single fan shaped slice of returning
ultrasound.
• Images are formed rapidly, allowing “real-time”
motion of cardiac structures to be displayed.
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2-Dimensional Echo
Right Ventricle (RV)
Interventricular
Septum (IVS)
Left Ventricle
(LV)
• This is a (static image)
cross section of the heart
obtained from the left
parasternal border
(parasternal short axis).
• Imagine the heart cut in
half at it’s midsection
along the short axis
(ventricular level).
• Displayed in this view:
 RV
 IVS
 LV
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2-Dimensional Echo
• To the left is a “real time” 2dimensional image of the heart
from the parasternal short axis
view.
• Note how in systole, the walls of
the left ventricle thicken and
contract in unison, and the cavity
size (dark area) decreases. This is
an example of normal systolic
function.
• The two lateral structures within
this cavity are the papillary
muscles of the left ventricle (part
of the mitral apparatus).
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2-Dimensional Echo
• The following slides are examples of normal anatomy
and cardiac function in “real time”
2-dimensional echocardiography (echo).
• These views are a sample of the most common views
that you will see in echo.
• Each new view will be prefaced by a static image that
defines cardiac anatomy.
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2-D Echo (Parasternal Long Axis)
RV
LV Apex
IVS
LV
Aortic Valve
Mitral Valve
• The parasternal long axis
view is obtained from the left
sternal border.
• Displayed in this view:
 RV
 IVS
 LV
 Aortic Valve (AV)
 Mitral Valve (MV)
 Left Atrium (LA)
Left Atrium
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2-D Echo (Parasternal Long Axis)
• To the left is a “real time” clip
of the parasternal long axis view
• Note that walls of the left
ventricle (IVS and LV posterior
wall - bottom) contract
simultaneously and with equal
thickening of the myocardium
(heart muscle).
• In diastole, the mitral valve is
open, in systole the mitral valve
is closed.
• Conversely, in diastole – the
aortic valve is closed, and in
systole the aortic valve is open.
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2-D Echo (Parasternal Short Axis)
RV
IVS
LV
• This is a (static image)
cross section of the heart
obtained from the left
parasternal border
(parasternal short axis).
• Imagine the heart cut in
half at it’s midsection
along the short axis
(ventricular level).
• Displayed in this view:
 RV
 IVS
 LV
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2-D Echo (Parasternal Short Axis)
• To the left is a “real time” 2dimensional image of the heart
from the parasternal short axis
view.
• This view is a perpendicular
view of the parasternal long
axis view
• In this view, the right ventricle
normally presents as a
concave attachment (upper
left) to the left ventricle
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2-D Echo (Parasternal Short Axis)
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2-D Echo (Parasternal Short Axis)
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2-D Echo (Apical 4 Chamber)
RV
IVS
LV
MV
TV
RA
LA
• As it’s name would imply, this is a
view that displays all 4 chambers
of the heart.
• This view is obtained with the
transducer placed at the 4-6th left
intercostal space (imaging from the
apex)
• The apex of the heart is displayed
at the top of the image (ventricles
on top, atria on the bottom)
• Note how the left heart structures
are displayed to the right and vice
versa.
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2-D Echo (Apical 4 Chamber)
• To the left is a “real time” clip
of the apical 4 chamber view
• Note that walls of the left
ventricle (IVS and LV lateral
wall – far right) contract
simultaneously and with equal
thickening of the myocardium
(heart muscle).
• In diastole, the mitral valve is
open, in systole the mitral
valve is closed.
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2-D Echo (Apical 5 Chamber)
Left Ventricular
Outflow Tract
(LVOT)
• The apical 5 chamber is a slight
modification (anterior
angulation) from the apical 4
chamber.
LV
MV
AV
LA
• This view brings into view the
left ventricular outflow tract and
the aortic valve.
• The right side of the heart is
somewhat obscured by the angle
of transducer orientation.
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2-D Echo (Apical 5 Chamber)
• In this view the mitral and
aortic valves are visualized
• Note again that in diastole, the
mitral valve is open, in systole
the mitral valve is closed.
• Conversely, in diastole – the
aortic valve is closed, and in
systole the aortic valve is
open.
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Motion Mode (M-Mode)
Echocardiography
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Motion Mode (M-Mode)
• One of the first types of echocardiography
• M-Mode imaging utilizes a single “ice-pick” sector of
the “real-time” image to display cardiac motion with
a (significantly) more rapid frame rate across time.
• Depth is displayed on the y-axis, and time is
displayed on the x-axis.
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Motion Mode (M-Mode)
• To the left is displayed a 2-D
image of a parasternal short axis
view.
• The red line represents the user
defined “sampling line” for the
display of motion (m-mode)
• Note that the line sampled cuts
through (or displays) in order
from top to bottom:
• RV freewall
• IVS
• LV posterior wall
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Motion Mode (M-Mode)
• In M-Mode, the motion
of all cardiac structures
along the sample line is
displayed over time
(left to right)
• Systole and Diastole are
evident by the decrease
in LV cavity size.
• The motion of the IVS
and LV Posterior wall
are synchronous in
contraction.
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Color Flow Doppler
Echocardiography
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Color Flow Doppler
• Utilizing the measured frequency shifts of blood flow though
the heart as sampled by ultrasound (i.e. Doppler Shift), blood
flow direction and velocity can be obtained.
• Color (flow) doppler echocardiography assigns a color to the
blood flow within a sampled area.
• Blood flow is assigned a color based upon 2 factors
• Flow direction
• Flow velocity
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Color Flow Doppler
• In color doppler echocardiography, a
“color scale” is utilized. This scale
determines the color of the blood flow
sampled and is typically displayed in the
upper left or right of the imaging screen.
• To the left is a typical color scale. Blood
that is traveling toward the transducer (or
top of image) is coded red and blood
traveling away from the transducer (or
bottom of image) is coded blue.
• Each direction has shades at their extreme
ends to depict a higher velocity of flow.
The numbers (56cm/sec in this example)
represent the higher ends of flow velocity.
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Color Flow Doppler
LV
LA
• To the left is an example of color
flow doppler.
• This apical 5 chamber view in
diastole shows the mitral valve
open and blood flowing into the
LV and toward the top of the
image (labeled red).
• The highest velocity of the
mitral inflow can be identified
by it’s yellow hue (as indicated
by the color scale in the top
right)
• Note the sample area is outlined
by a light blue box.
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Color Flow Doppler
• This is the same apical 5
chamber view in systole.
LV
LA
• Note how the blood leaving
the left ventricle through the
LVOT is coded blue.
• Also of note is a small amount
of mitral regurgitation. This is
displayed as a blue signal that
is passing though the closed
mitral valve during systole.
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Color Flow Doppler
• This is the real time clip
that demonstrates color
flow doppler interrogation
of the mitral and aortic
valves (apical 5 chamber
view)
• Again, in systole, note that
there is a small amount of
blue color flowing
retrograde into the left
atrium. This is mild mitral
regurgitation.
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Color Flow Doppler
• To the left is another
example of color
doppler interrogation
from the apical 4
chamber view.
• In systole, note again that there is a mitral
regurgitation. During
systole there should be
no blue signal present in
the left atrium. This is
classified as moderate
mitral regurgitation.
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Spectral Doppler
Echocardiography
Pulsed Wave Doppler
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Spectral Doppler
• Spectral doppler or “pulsed wave” doppler is used to measure
blood flow velocity at a discrete point within the heart. (e.g.
mitral valve, aortic valve, LVOT, etc.)
• A user defined “sample volume” is placed where the
measurement is desired, and the high frequency doppler shift
of the moving blood is sampled.
• The blood flow velocity is then displayed across time.
(velocity on the y-axis, time on the x-axis)
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Spectral Doppler
Sample
Volume
LVOT
• This is a static image of an
apical 5 chamber view in
systole.
• Color flow doppler displays a
blue signal as blood moves
away from the transducer (or
towards bottom of the screen)
• The pulsed wave sample
volume is placed in the LVOT
(dotted line with slightly
larger dot that represents area
to be sampled)
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Spectral Doppler
• This is a typical pulsed
wave/spectral doppler
display.
• The small picture in the upper
right displays where the
sample volume is placed (left
ventricular outflow tract)
• Blood that is traveling toward
the transducer or top of the
screen is posted above the
baseline. Conversely, blood
that is traveling away from
the transducer is posted below
the baseline.
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Spectral Doppler
•A 3-lead ECG is displayed (in
this example) in green and runs
across the top of the doppler
display.
•With the sample volume placed
in the left ventricular outflow
tract (LVOT), during systole
blood flow is moving away
from the transducer (or toward
the bottom of the screen) and is
therefore posted below the
baseline. This display may be
“frozen” so that velocity
measurements can be obtained.
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Spectral Doppler
Diastole
A
Systole
E
Passive
Active
Doppler
Baseline
•This is an example of the pulsed
doppler display of mitral valve
flow (or LV inflow). Blood flow
is moving toward the transducer,
so it is displayed above the
doppler baseline
•Note that there are 2 distinct
filling phases. The first diastolic
filling phase is “passive filling”
and is followed by “active
filling” precipitated by left atrial
contraction.
•The doppler term for these filling
phases are called the “E” and
“A” waves respectively.
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Echocardiography and
LV Systolic Function
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Regional LV Systolic Function
• LV systolic function can be divided into 2 categories:
Regional and Global.
• Regional systolic function describes the function of
specific segments or walls of the left ventricular
myocardium.
• Typically regional function is described in terms of:
•
•
•
•
•
•
Normal: normal motion and thickening
Hypokinetic: depressed motion or thickening
Akinetic: no motion or thickening
Dyskinetic: motion in the wrong direction with no thickening
Aneurysmal: “bulging out” from normal LV geometry with no
thickening
Tardokinetic: late motion or thickening (typical IVS motion with
BBB or Paced rhythm)
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Global LV Systolic Function
• Global systolic function describes how the LV pump is
functioning as a whole, regardless of how the individual
segments of the left ventricle myocardium are functioning.
For example: global LV systolic function may be preserved
even in the setting of myocardial infarction involving one
specific area of the heart causing “regional” LV systolic
dysfunction.
• The two most commonly used methods in echocardiography to
quantify global LV systolic function are:
•
•
Ejection Fraction
Stroke Volume
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Ejection Fraction (Method of Disks)
• Ejection fraction is a routinely measured index of
global systolic function in echocardiography
• The left ventricular cavity area is measured in two
long axis planes (Biplane) in both systole and
diastole.
• From these areas, volumes are produced and the
ejection fraction is calculated.
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Ejection Fraction (Method of Disks)
• Below is an example of one of the two planes used to calculate ejection
fraction (apical 4 chamber view). In each example, the LV is traced and long
axis identified by a line running from the mitral annulus level to the LV apex.
• Each traced area is subdivided into “disks” along the long axis plane, and the
volume of the disks is added yielding a total cavity volume.
LV
RV
RV
RA
LV
RA
LA
LA
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Stroke Volume (Doppler Method)
• Utilizing doppler echocardiography, stroke volumes can be
obtained with relative ease.
• This doppler volume calculation is based upon the volume
calculation of a cylinder
• By tracing the doppler velocity profile of the LVOT, two
parameters are measured:
• Average systolic flow velocity (cm/sec)
• Ejection time (sec)
• This traced measurement is known as the VTI or velocity time
integral
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Stroke Volume (Doppler Method)
•This is an example of a
LVOT VTI.
•Note that the units of
measure are centimeters
(for distance).
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Stroke Volume (Doppler Method)
• As distance is defined as: average velocity X time, the “stroke
distance” can be calculated. That is, the distance that the blood
travels with one “stroke” through the left ventricular outflow tract.
• By measuring the LVOT diameter and calculating its area, we
have the last part of the equation needed to calculate the volume of
a cylinder (the base).
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Stroke Volume (Doppler Method)
• Because the LVOT diameter is relatively constant in size
regardless of systolic function, the LVOT VTI can be used to
follow changes in systolic function on almost a “beat to beat”
basis. This method has lent itself well to the process of CRT.
• Care must be taken by the sonographer however, to ensure that the
doppler sample volume remains steady, and that respiratory
changes in the hearts position are taken into account. This is
typically done by taking doppler measurements at end expiratory
apnea and measuring multiple cycles to ensure reproducibility.
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Atrioventricular (AV-PV) Optimization
with Echocardiography
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Atrioventricular Optimization
• There are currently two commonly used
methods for atrioventricular optimization:
• Ritter Method
• Iterative Method
• An example of the Iterative Method will be
shown in the following slides
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Atrioventricular Optimization
• The goal of AV optimization
is to give the atria time to
complete its active filling
phase (maximizing atrial
contribution of
volume/pressure) prior to the
onset of ventricular
contraction.
• Doppler echocardiography
allows us to track the “active
filling” phase or “A” wave in
real-time.
A
E
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Atrioventricular Optimization
• The objective, using doppler echocardiography, is to set
the AV/PV interval to the shortest time possible that
allows the completion of active filling – without truncation
of the A wave.
• This is performed by setting the initial time high (usually
around 200-220 ms) and decreasing in 10-20 ms intervals
until obvious truncation is seen. Then increasing in
intervals of 5-10 ms until truncation is no longer evident.
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Atrioventricular Optimization
• Starting at 200 ms, the E and A waves are merged. As the
time is decreased in 20 ms intervals, we can see the E and A
waves (although still somewhat merged) begin to separate.
• Note that the doppler waveform of the A wave is symmetrical
in its upslope and downslope. There is no truncation evident
at the lowest setting of 160 ms. At this point we know that we
need to decrease the time further.
200 ms
180 ms
Merged
A
160 ms
E
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Atrioventricular Optimization
• Proceeding from 160 ms, the time is lowered in 20 ms
intervals. At 140 ms the A wave starts to lose its symmetry.
Note how the downslope of the A wave is noticeably steeper
than its upslope. This is truncation of the A wave.
• At 120 ms the truncation is more obvious.
Truncation
Truncation
160 ms
A
140 ms
120 ms
E
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200 ms
Merged
Atrioventricular Optimization
• In this example the optimized setting
was 160 ms.
160 ms
A
E
120 ms
Truncation
• Note how as the time is decreased the
A wave shifts to the right.
• It is important to note that when
obtaining these doppler parameters,
multiple samples should be taken, and
every attempt should be made to take
samples at end expiratory apnea for
reproducibility.
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