2. ECHO
• Echo is something you experience all
the time.
• If you shout into a well, the echo comes
back a moment later.
• The echo occurs because some of the
sound waves in your 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 your ears.
• A similar principle applies in cardiac
ultrasound.
2
3. HISTORY
1. Dr. Helmut Hertz of Sweden in 1953 obtained a commercial
ultrasonoscope, which was being used for nondestructive
testing.
2. He then collaborated with Dr. Inge Edler who was a practicing
cardiologist in Sweden.
3. The two of them began to use this commercial
ultrasonoscope to examine the heart.
4. This collaboration is commonly accepted as the beginning of
clinical echocardiography as we know it today.
4. 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..
•There is no special preparation for the
test.
5. GENERATION OF AN ULTRASOUND
IMAGE
• The transducer
transforms the echo
(mechanical energy) into
an electrical signal which
is processed and
displayed as an image on
the screen.
• The conversion of
sound to electrical
energy is called the
piezoelectric effect.
6. MACHINES
There are 5 basic components
of an ultrasound scanner that
are required for…
Generation
Display
Storage
of an ultrasound image.
1. Pulse generator - applies
high amplitude voltage to
energize the crystals
2. Transducer - converts
electrical energy to
mechanical (ultrasound)
energy and vice versa
3. Receiver - detects and
amplifies weak signals
4. Display - displays
ultrasound signals in a
variety of modes
5. Memory - stores video
display
8. THE TRANSDUCER
The transducer is responsible for both transmitting and
receiving the ultrasoundsignal.
The transducer consist of a electrode and a piezo-electric
crystal whose ionic structure results in deformation of shape
when exposed toan electric current.
9. THE TRANSDUCER
Piezo electric(PE) crystals are composed of synthetic material
such as barium titanate which when exposed to electric
current from the electrodes, alternatelyexpand and contract
to create sound waves.
When subjected to the mechanical energy of sound from a
returning surface, the same PE element change the shape
thereby generating an electrical signal detected by the
electrodes.
17. Parasternal Long-Axis View (PLAX)
1. Transducer position: left sternal
edge;
2. 2nd – 4th intercostal space
3. Marker dot direction: points
towards right shoulder
4. Most echo studies begin with
this view
5. It sets the stage for subsequent
echo views
6. Many structures seen from this
view
19. Parasternal Short Axis View (PSAX)
Transducer position: left sternal
edge; 2nd – 4th intercostal space
Marker dot direction: points
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
22
28. Sub–Costal 4 Chamber View(SC4CH)
1. Transducer position: under the
xiphisternum
2. Marker dot position: points towards left
shoulder.
3. The subject lies supine with head slightly low (no pillow). With
feet on the bed, the knees are slightly elevated
4. Better images are obtained with the abdomen relaxed and
during inspiration
5. Interatrial septum, pericardial effusion, desc abdominal aorta
30. Suprasternal View
• Transducer position: suprasternal notch
• Marker dot direction: points towards left jaw
• The subject lies supine with the neck
hyperexrended. 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
31. ECHO TECHNIQUES
Three echo methods are in common clinical
usage:
• Two-dimensional (2-D) or ‘cross-sectional’
• Motion or m-mode
• Doppler –
• Continuous wave,
• Pulsed wave and
• Colour
40. Some Other Normal Findings
• Mild tricuspid and mitral regurgitation (MR) are found in
many normal hearts.
• Some degree of thickening of AV leaflets with ageing is normal
without significant aortic stenosis.
• Mitral annulus (ring) calcification is sometimes seen in older
subjects.
– It is often of no consequence but may be misdiagnosed as
a stenosed valve, a vegetation (inflammatory mass),
thrombus (clot) or myxoma (cardiac tumour).
– It is important to examine the leaflets carefully. It may be
associated with MR.
45. MS
Changes in MV area with severity of
MS
Normal valve : 4–6 cm2
Mild MS : 2–4 cm2
Moderate MS : 1–2 cm2
Severe MS : <1 cm2.
Criteria for diagnosis of severe
MS (many derived from
Doppler)
• Measured valve orifice area <1 cm2
• Mean pressure gradient >10 mmHg
• Pressure half-time >200 ms
• Pulmonary artery systolic pressure
>35 mmHg.
64. Pulmonary hypertension
• This is defined as an abnormal increase in PA pressure
above:
– 30/20 mmHg (normal 25/10 mmHg)
– Mean 20 mmHg at rest
– Mean 30 mmHg during exercise.
• In those aged over 50 years, PHT is the third most
frequent cardiovascular problem after coronary artery
disease and systemic hypertension.
• Echo is useful in assessing the underlying cause and
severity of PHT, but echo examination can be technically
more difficult since many of these individuals have
underlying lung disease. This is especially true if the lungs
are hyperinflated or there is pulmonary fibrosis.
65. The echo features of PHT
M-mode
– Abnormal M-mode of the pulmonary valve leaflets with
absent A-wave or mid-systolic notch
– Dilated RV with normal LV
– Abnormal IVS motion (‘right ventricularization’ of IVS)
– Underlying cause, e.g. MS (PA systolic pressure is an index
of severity).
66. • 2-D echo
– Dilated PA (e.g. parasternal short-axis view at aortic
level). The PA diameter should normally not be greater
than aortic diameter
– RV dilatation and/or hypertrophy
– RA dilatation
– Abnormal IVS motion
– Underlying cause, e.g. MV or AV disease, ASD, VSD, LV
dysfunction.
• Doppler
– This is the best method to assess PA systolic pressure
using TR velocity (as described in Ch. 3), or short PA
acceleration time as a surrogate of PHT.