Echo tee and tte

ECHO (CARDIAC ULTRASOUND)
Echo is something we experience all the time.
If we shout into a well, the echo comes back a
moment later. The echo occurs because some
of the sound waves in our shout reflect off a
surface (either the water at the bottom of the
well or the wall on the far side) and travel back
to our ears. A similar principle applies in
cardiac ultrasound.

GENERATION OF AN ULTRASOUND IMAGE

Echocardiography (echo or
echocardiogram) is a type of ultrasound
test that uses high-pitched sound waves to
produce an image of the heart.

The sound waves are sent through a
device called a transducer and are
reflected off the various structures of the
heart.

These echoes are converted into pictures
of the heart that can be seen on a video
monitor.

 Transducers, typically made of quartz or
titanate ceramic, use crystals that exhibit the
piezoelectric effect

PROPERTIES OF ULTRASOUND
 WAVELENGTH,
 AMPLITUDE
 FREQUENCY
 PROPAGATION VELOCITY
 IMAGE RESOLUTION
 ATTENUATION
 ACOUSTIC IMPEDENCE
 GAIN
 PRF

 sequence of compression and rarefaction is described
by sine waves
 characterized in terms of
 Wavelength distance between two peaks of the sine wave
 Frequency number of cycles that occur in 1 second
 Amplitude measure of tissue compression
 Propagation velocity speed of an ultrasound wave traveling through
tissue

 Echocardiography uses frequencies of 2.5 to 7.5
million cycles/sec (MHz)

 Image resolution is characterized in terms
of

 Axial resolution(along length)

 Elevational resolution(thickness of image)

 Temporal resolution(ability to accurately locate
moving structures at a particular instant in time)

 Lateral resolution(increased frequency-less
divergence

 Attenuation :- a function of tissue
absorption , divergence of ultrasound
energy as it moves away from the
transducer, reflection, and scattering

 Acoustic impedance :- refers to the resistance
that an ultrasound wave meets when traveling
though tissue

 Mismatches in acoustic impedance and
attenuation are important to consider in imaging
the heart

 For example, the upper aortic arch is difficult to
visualize from the esophagus

 GAIN
-to amplify low amplitude ultrasound waves
reflected back to transducer

 PULSE REPETITION FREQUENCY
-no of pulses that leave or are returned back
to transducer in a single second
-image depth increases PRF decreases

THE MODALITIES OF ECHO
The following modalities of echo are used clinically:
1. Conventional echo
Motion- mode echo (M-mode echo)
Two-Dimensional echo (2-D echo)
3-D ECHO

2. Doppler Echo
Continuous wave (CW) Doppler
Pulsed wave (PW) Doppler
Colour flow(CF) Doppler

All modalities follow the same principle of ultrasound
Differ in how reflected sound waves are collected and analysed

M-MODE ECHOCARDIOGRAPHY
An M- mode echocardiogram is
not a "picture" of the heart, but
rather a diagram that shows how
the positions of its structures
change during the course of the
cardiac cycle.
M-mode recordings permit
measurement of cardiac
dimensions and motion patterns.
Also facilitate analysis of time
relationships with other
physiological variables such as
ECG, and heart sounds.

TWO-DIMENSIONAL ECHO
(2-D ECHO)

This technique is used to "see" the
actual structures and motion of the
heart structures at work.
Ultrasound is transmitted along
several scan lines(90-120), over a
wide arc(about 900) and many times
per second.
The combination of reflected
ultrasound signals builds up an image
on the display screen.
A 2-D echo view appears cone-
shaped on the monitor.

3-D ECHO
 The advance from 2D to real-time 3D echocardiography has
proved difficult.
 The time needed to acquire the requisite 2D images, the
computing challenge of collating them into 3D images, and
the display challenge of depicting 3D images on a 2D video
screen all contributed to the difficulty.
 Matrix-array transducers typically, contain over 3000
imaging elements and electronically rotate the 2D ultrasound
beam through 180 degrees in milliseconds to acquire the
requisite 2D images in a fraction of the time possible with
mechanically rotated multiplane transducers.


DOPPLER ECHOCATDIOGRAPHY

 DOPPLER SHIFT(CHRISTIAN DOPPLER)
 The ultrasound that bounces off moving red
blood cells is reflected back to the transducer
at a slightly different frequency than that
emitted from the transducer. The shift in
frequency allows the ultrasound machine to
estimate blood flow velocity and direction of
flow.

DOPPLER ECHOCARDIOGRAPHY
Doppler echocardiography is a
method for detecting the direction
and velocity of moving blood within
the heart.
Pulsed Wave (PW) useful for low
velocity flow e.g. MV flow
Continuous Wave (CW) useful for
high velocity flow e.g aortic stenosis
Color Flow (CF) Different colors are
used to designate the direction of
blood flow. red is flow toward, and
blue is flow away from the
transducer with turbulent flow shown
as a mosaic pattern.

Doppler Advantages Disadvantages Clinical Uses
Technique
Pulsed Measures blood Cannot measure To measure blood
wave flow velocities at fast blood flow flow velocities
selected areas of velocities through the
interest 3-5 mm (>1 m/sec) because pulmonary veins and
wide along the of aliasing mitral valve and in
ultrasound scan line low-flow areas within
the heart
Continuous Detects blood flow Cannot identify To measure blood
wave velocities up to location of the flow velocities
7 m/sec (not subject peak velocity through the aorta,
to the Nyquist limit) along the aortic valve, stenotic
ultrasound scan valve lesions, and
line regurgitant valvular
jets
Color flow Presents the spatial Like pulsed wave To enhance
relationships Doppler, cannot recognition of
between structure measure fast blood valvular
and blood flow flow velocities abnormalities, aortic
because of dissections, and
aliasing intracardiac shunts

 One limitation of PWD is that it may be too slow
to capture the velocity of fast-moving blood
cells. This phenomenon is known as aliasing.
 The limit at which the sampling rate fails to
accurately capture the true velocity is called the
Nyquist limit
 Aliasing of PWD occurs at blood flow velocities
greater than 0.8 to 1.0 m/sec. Normal flow
within the heart may reach 1.4 m/sec and
pathologic flow up to 6 m/sec.

REASONS FOR SUCCESS OF TEE

1. Close proximity of esophagus to post
wall of heart – no intervening structure
like bone or lung

2. Monitor the heart over time, such as
during cardiac surgeries

3. Extremely safe & well tolerated so that it
can be performed in critically ill patients
& very small infants

CATEGORY 1 INDICATIONS FOR TEE
 Intraoperative evaluation of acute, persistent, and life-threatening
hemodynamic disturbances
 Intraoperative use in valve repair
 Intraoperative use in congenital heart surgery for most lesions
requiring cardiopulmonary bypass
 Intraoperative use in repair of hypertrophic obstructive
cardiomyopathy
 Intraoperative use for endocarditis when preoperative testing was
inadequate or extension of infection to perivalvular tissue is
suspected
 Preoperative use in unstable patients with suspected thoracic
aortic aneurysms, dissection, or disruption who need to be
evaluated quickly
 Intraoperative assessment of aortic valve function during repair of
aortic dissections with possible aortic valve involvement
 Intraoperative evaluation of pericardial window procedures
 Use in the intensive care unit for unstable patients with
unexplained hemodynamic disturbances, suspected valve disease

EQUIPMENT DESIGN AND OPERATION

 A miniaturized echocardiographic transducer
(about 40 mm long, 13 mm wide, and 11 mm
thick) mounted on the tip of a gastroscope.

 Transducer is with 64 piezoelectric elements
operating at 3.7 to 7.5 MHz

 Like standard
gastroscopes two
rotary knobs control
the movements

CONTRAINDICATIONS

 Absolute

1. Previous esophagectomy,
2. Severe esophageal obstruction,
3. Esophageal perforation, and
4. Ongoing esophageal hemorrhage

CONT.

 Relative
1. Esophageal diverticulum,
2. Varices,
3. Fistula, and
4. Previous esophageal surgery, history of
gastric surgery, mediastinal irradiation,
unexplained swallowing difficulties

PATIENT PREPARATION

 Informed consent
 Pt. should fast for at least 4 – 6 hrs

 Thorough history should be taken – any
dysphagia
 i.v. access

 Pre oxygenation

 Suction should be available

BASIC TRANSESOPHAGEAL
EXAMINATION
 Patient is anesthetized (topically)

 The contents of the stomach are suctioned

 Patient's neck is then extended and the
well-lubricated TEE probe is introduced

 If the probe does not pass blindly, a
laryngoscope can be used

TRANSESOPHAGEAL ECHOCARDIOGRAPHY

TEE VIEWS

Upper oesophageal (UE)
level 20-25cm
Mid Esophageal (ME) level
30-40cm
Trans Gastric (TG) level
beyond 40 cm

TRANSGASTRIC
VIEWS
MOST IMPORTANT
TRANSESOPHAGEAL VIEWS
BEST FOR EVALUATING LEFT
AND RIGHT VENTRICULAR
FUNCTION
COMMONLY EMPLOYED INTRA
OPERATIVE TEE TO ASSESS
EJECTION FRACTION AND
WALL MOTION POST-
OPERATIVELY
DEEP TRANSGASTRIC VIEWS
ARE THE BEST VIEWS TO
OBTAIN ACCURATE
GRADIENTS ACROSS THE
AORTIC VALVE TO ASSESS
THE DEGREE OF AS OR AR

TRANSGASTRIC SHORT AXIS 0 DEGREES

AT PAPILLARY MUSCLE LEVEL

MITRAL VALVE LEVEL

TRANSGASTRIC SHORT AXIS 0-30
DEGREES
AT TRICUSPID VALVE LEVEL

TRANSGASTRIC SHORT AXIS 30-60
DEGREES
AT RVOT

TRANSGASTRIC LONG AXIS
90 DEGREES LV

TRANSGASTRIC LONG AXIS 90 DEGREES
MITRAL VALVE

TRANSGASTRIC LONG AXIS 90 DEGREES
LV

TRANSGASTRIC LONG AXIS 110-130
DEGREES
LVOT AND AORTIC VALVE

HIGH ESOPHAGEAL
HIGH ESOPHAGEAL VIEWS ARE
HELPFUL FOR EVALUATING THE
GREAT VESSELS INCLUDING
THE AORTIC ROOT AND
CORONARY ARTERIES,
ASCENDING AORTA AND THE
PULMONARY ARTERY. A
USEFULL LANDMARK IS THE
MID-ESOPHAGEAL VIEW OF THE
AORTIC VALVE IN SHORT AXIS AT
40-60 DEGREES. BY
WITHDRAWING FROM THE
LEVEL OF THE AORTIC VALVE,
THE ORIGIN OF THE CORONARY
ARTERIES CAN BE VISUALIZED

TRANSTHORACIC ECHO
A standard echocardiogram is also known
as a transthoracic echocardiogram (TTE),
or cardiac ultrasound.
The subject is asked to lie in the semi
recumbent position on his or her left side
with the head elevated.
The left arm is tucked under the head and
the right arm lies along the right side of
the body
Standard positions on the chest wall are
used for placement of the transducer
called “echo windows”

PARASTERNAL LONG-AXIS VIEW (PLAX)

Transducer position: left
sternal edge; 2nd – 4th
intercostal space
Marker dot direction: points
towards right shoulder
Most echo studies begin with
this view
It sets the stage for
subsequent echo views
Many structures seen from
this view

PARASTERNAL SHORT AXIS VIEW (PSAX)
Transducer position: left sternal
edge; 2nd – 4th intercostal space
towards left shoulder(900
clockwise from PLAX view)
By tilting transducer on an axis
between the left hip and right
shoulder, short axis views are
obtained at different levels,
from the aorta to the LV apex.
Many structures seen

PAPILLARY MUSCLE (PM)LEVEL

PSAX at the level of
the papillary muscles
are used usually for
the purposes of
describing abnormal
LV wall motion
LV wall thickness can
also be assessed

APICAL 4-CHAMBER VIEW (AP4CH)
Transducer position:
apex of heart
Marker dot direction:
points towards left
shoulder
The AP5CH view is
obtained from this
view by slight anterior
angulation of the
transducer towards
the chest wall. The
LVOT can then be
visualised

APICAL 2-CHAMBER VIEW (AP2CH)

Transducer position: apex
of the heart
Marker dot direction:
points towards left side of
neck (450 anticlockwise
from AP4CH view)
Good for assessment of
LV anterior wall
LV inferior wall

SUB–COSTAL 4 CHAMBER VIEW(SC4CH)
Transducer position: under the
xiphisternum
Marker dot position: points
towards left shoulder
The subject lies supine with head
slightly low (no pillow). With feet
on the bed, the knees are slightly
elevated
Better images are obtained with
the abdomen relaxed and during
inspiration
Interatrial septum, pericardial
effusion, abdominal aorta are seen

SUPRASTERNAL VIEW
Transducer position: suprasternal
notch
towards left jaw
The subject lies supine with the
neck hyperextended. The head is
rotated slightly towards the left
The position of arms or legs and
the phase of respiration have no
bearing on this echo window
Arch of aorta is seen

ASSESSMENT OF HEMODYNAMICS

 1.Evaluation of Ventricular Filling
-measurement of EDA
-LV filling pressure
 2.Estimation of Cardiac Output

- measuring both the velocity and the cross-
sectional area of blood flow at appropriate
locations in the heart or great vessels gives
stroke volume

CONT.
 3.Assessment of Ventricular Systolic
Function
Fractional area change (FAC) during systole
is a commonly used measure of global LV
function.

FAC = (EDA - ESA)/EDA

CONT.
 4.Assessment of Ventricular Diastolic
Function
-E/A ratio
-E wave (higher-velocity component across
mitral valve generated by atrial pressure and
ventricular relaxation in early diastole)
-A wave(second lower-velocitycomponent
generated by atrial contraction in late
diastole)

ASSESSMENT OF VENTRICULAR
DIASTOLIC FUNCTION

5.DETECTION OF MYOCARDIAL
ISCHEMIA
 Within seconds after the onset of myocardial
ischemia, affected segments of the heart
cease contracting normally
 New intraoperative segmental wall motion
abnormalities (SWMAs) diagnostic of
myocardial ischemia
 Not all SWMAs are indicative of myocardial
ischemia(myocardial stunning,severe
hypovolemia)

6.VALVULAR PATHOLOGIES
 MS
-ME 4 chamber, 2 chamber LAX
-in 2 D ECHO appears as thickened dome
towards LV
-color flow doppler shows turbulent jet flow into
LV
 MR
-similar views as for MS

GRADING FOR MITRAL REGURGITATION
Jet Width at Jet Area (% LAa) Jet Depth (% LAd)
Origin (mm)

MILD >2 <25 <50

MODERATE 3-5 25-50 50-90

SEVERE >5 <50 >100

VALVULAR PATHOLOGIES
 AS
-ME AV SAX shows thickening of aortic leaflets
-Deep TG LAX with CWD estimates pressure
gradient across the AV
 AR
-ME AV LAX
- With color Doppler positioned over the leaflets
and outflow tract, aortic regurgitation is
recognized as a color jet emanating from the
valve during diastole

GRADING FOR AORTIC INSUFFICIENCY
Jet Width at Jet Area (% LVOT) Jet Depth into the
Origin (mm) LV (cm)

MILD <2 <33 1-2

MODERATE 3-5 <66 3-5

SEVERE >5 100 >5

7. STRESS ECHO
 New regional wall motion abnormalities, a decline in
ejection fraction, and an increase in end-systolic
volume with stress are all indicators of myocardial
ischemia. Exercise stress testing is usually done with
exercise protocols using either upright treadmill or
bicycle exercise. Pharmacologic testing can also be
performed by infusion of dobutamine to increase
myocardial oxygen demand. Dobutamine
echocardiography has also been used to assess
myocardial viability in patients with poor systolic
function and concomitant CAD.
 It determine the hemodynamic response to stress, In
patients with low-output, low-gradient aortic stenosis

UNDERSTANDING ECHO REPORT
 LEFT VENTRICLE
WALLS IVS(d) 0.6-1.1 cm
IVS(s) 0.8-2.0 cm
PW(d) 0.6-1.1 cm
PW(s) 0.8-2.0 cm
CHAMBERS
LVID(d) 3.7-5.6 cm
LVID(s) 1.8-4.2 cm
RWT <0.42 cm
SYSTOLIC FUNCTION
FS 34-44%
EF >50%
MASS LVMI 50-95 g/m2
women men
RANGE MILD MODER SEVER RANGE MILD MODER SEVER
ATE E ATE E
EF >55 45-54 30-44 <30 >55 45-50 30-44 <30
(%)

UNDERSTANDING ECHO REPORT
 RIGHT VENTRICLE
RVD (at base) 2.6-4.3 cm
 LEFT ATRIUM
LAD(anteroposterior) 2.3-3.8 cm
LAV ( ml/m2) 16-28
 Aortic root dimension (cm) 2.0–3.5
 Aortic cusps separation (cm) 1.5–2.6
 Pulmonary AA dia 1.5-2.1 cm(mild 2.2-2.5,moderate
2.6-2.9, severe >3 cm)
 Mitral flow (m/s) 0.6–1.3
 Tricuspid flow (m/s) 0.3–0.7
 Aorta (m/s) 1.0–1.7
 Pulmonary artery (m/s) 0.6–0.9

CONCLUSION
Echocardiography provides a substantial
amount of structural and functional
information about the heart.
Still frames provide anatomical detail.
Dynamic images tell us about
physiological function
The quality of an echo is highly operator
dependent and proportional to
experience and skill, therefore the value
of information derived depends heavily
on operation and interpretation

Echo tee and tte

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