09/2006 HKCEM 1

Emergency

Echocardiography

An introduction

Dr. KL Mok

Associate Consultant

AED RHTSK

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Today’s Lecture

� Basic principle of Echocardiography

� Normal heart appearance in Echo

� Clinical Applications in ED

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ECHO equipment

� The ECHO transducers:

– Frequency of transducer: 3.5-

5Mhz

– Phased array of pizeo-electric

crystals in the transducer

– Small foot-print: to struggle

between the intercostal spaces

– An index marker available for

orientation

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ECHO equipment

� The USG machine:

– Basic 2D image/grey scale

– M Mode

– Continuous Wave Doppler

– Pulsed Wave Doppler

– Colour Flow Mapping/imaging

– Cine loop mode: to allow frame to frame assessment

– Cardiac Package for calculation (optional for ED)

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ECHO patients� Undress the top

� Supine position

� Turn slightly left lateral for better ECHO image

� Bend the knee up for subcostal views; Hyperextend the neck for suprasternal views

� Adequate Sonic Gel

� With 3-lead ECG monitor

� Poor ECHO images in:– Morbid Obese

– COAD/hyperinflated chest

– Chest wall deformity

– ?Big Breast

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Orientation of ECHO image

� Based on the standards

recommended by American

Society of Echocardiography

– The image index marker should

appear on the right side of the

image display [reverse for

Mayo Clinic Technique]

– In contrast to the conventional

abdominal USG [left side

orientation]

Circulation 1980 62: 212-217

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ECHO (acoustic) windows

� In order for the USG beam to reach the heart

without being obscured by the ribs or absorbed by

the lung (air space),

� Several orthodox windows are commonly used:

– Parasternal window

– Apical window

– Subcostal window

– Suprasternal window

– Right parasternal window

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ECHO windows

[SUBCOSTAL]

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ECHO planes

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ECHO Views

� Parasternal veiws– Long and Short axes

� Apical views– 4 Chamber view

– 5 Chamber view

– Long axis (2 Chamber)

� Subcostal views– Long and short axes

� Suprasternal views– Long and short axes

Circulation 62: 212-217, 1980

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Parasternal views

Long axis view

Short axis view

Probe positionProbe position

••Short axis: turn the marker Short axis: turn the marker

pointing to left shoulder at pointing to left shoulder at

the point where a long axis the point where a long axis

view is taken [ie turn 90 view is taken [ie turn 90

degree clockwise].degree clockwise].

••Long axis: index marker of Long axis: index marker of

transducer pointing to the transducer pointing to the

right shoulderright shoulder..

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Parasternal Long Axis

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Parasternal Short Axis

� By tilting and shifting along the line of the

long axis, a series of views from apex to the

pulmonary artery can be obtained.

Pulmonary artery level

Aortic valve level

Mitral valve level

Apex level

Papillary muscle level

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Parasternal Short Axis

� At the level of papillary muscles

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Parasternal Short Axis

� At the level of aortic valve

Right Coronary Right Coronary

CuspsCusps

Left Coronary Left Coronary

CuspsCusps

NonNon--Coronary Coronary

CuspsCusps

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Apical Views

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Apical Views

Probe position

– 4 chamber: Palpate the apex beat. Place the transducer at the apex towards the patient’s head. Index marker is rotated to approximately 3 o’clock position.

– 5 Chamber: Fanning of the transducer at apex to open up the LVOT and Aortic valve [the 5th chamber].

– Long axis: Rotate the transducer 90 anticlockwise with the index marker pointing at the suprasternal notch.

– 2 chamber: Rotate the transducer 45 clockwise from the long axis view.

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Apical 4 Chamber

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Apical 2 Chamber

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Subcostal views

Probe PositionProbe Position

••4 Chamber: Place 4 Chamber: Place

transducer below the transducer below the

xyphoid process. The index xyphoid process. The index

marker is rotated to 3 marker is rotated to 3

oo’’clock position.clock position.

••Short axis: Rotate the Short axis: Rotate the

transducer 90 degree antitransducer 90 degree anti--

clockwise so that the index clockwise so that the index

marker is pointing at 12 marker is pointing at 12

oo’’clock position.clock position.Subcostal long axis

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Subcostal Long Axis

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Subcostal Short Axis

� Similar to the parasternal short axis view

� Can show the heart at different levels

� Good view for IVC assessment

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ECHO Dynamic Assessment

� 2D image: anatomical assessment, valvular movement, RWMA

� M mode: motion assessment over time, distance or depth measurement

� CW and PW: haemodynamic assessment, calculate velocity, then pressure gradients

� CFM: both haemodynamic and anatomical information

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2D Optimization

� Overall Gain:

– Chamber cavities should be black while the ventricular walls should appear grey.

� Time Gain Control:

– Reversed C-shaped for parasternal and apical views

– \-shaped or curved in subcostal views

� Depth of view:

– The screen should be about 1/5 beyond the posterior pericardium.

� Focal Zone:

– Focus at the valve level

– Mid part of ventricle for LV measurements

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The Normal Heart

� Parasternal Long axis

� Parasternal Short axis

– Aortic Valve level

– Mitral Valve level

� Apical 4 chamber

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Emergency ECHO

� 1st employed in ED in 1980s in USA

� Allows rapid recognition of life-threatening conditions and direct appropriate intervention and treatments.

� Mainly a focused exam and try to answer clinical questions

� Most situations require only a 2D scan. Doppler may help.

Emerg Med Clinic N Am 2004 22: 621-640

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Clinical Indications� Primary indications

– Detection of Pericardial Effusion +/- Cardiac Temponade

– Evaluation of cardiac activity in cardiac arrest patients

– LV systolic fx evaluation

� Extended indications– Estimation of intravascular volume status

– RV evaluation

– Evaluation of proximal aorta for dissection/aneursym

– Procedural Guidance

ACEP Policy Statement. Em USG

imaging Criteria Compendium April 2006

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Emergency Conditions where

ECHO can help!

� Trauma

� Cardiac Arrest

� Unexplained hypotension

� Shortness of Breath

� Chest Pain

� Procedural Guidance for pericardiocentesis

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Trauma

� Part of FAST scan nowadays in ATLS

� Mainly detecting pericardial effusion and

cardiac temponade

� Prognostic benefit for penetrating chest

injury patients

� Urgent pericardiocentesis is required for

patient with features of cardiac temponade

Ann Emerg Med 1992 21(5): 709-12

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Pericardial Effusion� Detection of echo-free rim around the heart within the

hyperechoic parietal pericardium

� Maybe complex echogenic if fluid accumulation is due

to inflammation and malignancy

� False +ve: pleural effusion and epicardial fat pad

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Pericardial Effusion

Subcostal Short

axis view

� Subcostal views

� Parasternal views

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Pericardial Effusion

Pericardial

effusion

Size Location

Small <10mm in diastole Posterior only and not

circumferential

Moderate <=10mm in diastole circumferential

Large 10-20mm circumferential

Very large >20mm Circumferential+/-

features of temponade

ACEP Policy Statement. Em USG imaging

Criteria Compendium April 2006

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Cardiac Tamponade

� Pericardial effusion causing haemodynamic

collapsed because of impaired ventricular filling

and, in turn, cardiac output.

� Acute accumulation of even small amount of fluid

in pericardial sac can have significant

haemodynamic effect. [rigid fibrous sac]

� Beck’s Traid: Elevated JVP, Muffled heart sounds,

hypotension

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Cardiac Tamponade

� ECHO features:

– RA and RV diastolic collapse

– RV free wall moves towards the RV cavity

early in diastole [normally it moves away]

– RA moves inwards at the end of diastole and

the beginning of systole.

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Cardiac Tamponade

� RA free wall invagination during diastole

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ECHO guided

pericardiocentesis

� Confirm the

diagnosis

� Locate the site of

drianage

� Confirm the

success of

procedure

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Cardiac Arrest

� Mainly detect organized cardiac activity

� To find the treatable causes of Pulseless

Electrical Activity:

– Cardiac Tamponade

– Hypovolaemia

– +/-Massive PE

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Unexplained Hyptoension

� Obtain subcostal or parasternal long-axis views

� Assess for pericardial effusion and tamponade

� Assess for wall-motion abnormalities:

– large hypocontractile LV segment

• primary LV failure

• inotropic support

– RV hypokinesis & normal LV function• RV infarction or massive PE

• try fluid resuscitation

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Unexplained Hypotension

� Hypovolaemia

– small heart with near complete systolic

emptying

– flat IVC with exaggerated normal respiratory

variation

� Assess abdomen for AAA and

haemoperitoneum

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LV systolic Fx Evaluation

� Useful in managing hypotensive patients

� To differentiate cardiogenic or non-

cardiogenic shock

� LV systolic fx can be accurately assessed by

EP in hypotensive patients.

Acad Emerg Med 2002 9(3): 186-93

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LV systolic Fx Evaluation

� M mode

– Measurement of LV dimension

– LVEDD [normal=3.5-5.6 cm] measured at Q

wave

– LVSDD [normal=2.0-4.0 cm] measured at end of

T wave

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LV Systolic Fx Evaluation

� Calculation of Fractional Shortening

– %FS=LVEDD-LVESD/LVEDD x 100%

– Normal=30-45%

– Parasternal Long Axis View with M-mode

cursor just below the MV leaftlets,

perpendicular to the IVS

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LV Systolic Fx Evaluation

� 2D Echo

– Simpson’s Method

– Apical 2 or 4 chamber view

– Divide the LV into different slides

of known thickness

– Volume size=Slice area X Slice

thickness

– EF=LVEDV-LVESV/LVEDV x 100%

– Normal=50-70%

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LV systolic Fx Evaluation� Evaluation by ‘eye-balling’

� Impaired LV fx EF=25%

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Preload assessment

� Normally IVC collapsed with inspiration

� Hypovolaemia: collapsed IVC

� RVF/ RV MI, Massive PE, TR, Cardiac Temponade: distended IVC and Loss of inspiratory Collapse

� Semi-quantitative estimation of RAP possible IVC without inspiratory collapse in patient with

PE [IVC=2.1cm]

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Preload assessment

IVC size Change with

inspiration

Estimated

RAP

Hypovolaemic <1.5cm Collapsed 0-5mmHg

Normal 1.5-2.5cm Decrease >50% 5-10mmHg

Normal 1.5-2.5cm Decrease <50% 10-15mmHg

Dilated >2.5cm Decrease <50% 15-20mmHg

Dilated >2.5cm +

Distended

Hepatic Vein

No Change >20mmHg

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Chest Pain

� Possibly detectable Causes by ECHO:

– AMI, ACS—regional wall motion abnormality

– Aortic Dissection—dialated Ao, visible intimal

flap

– Pulmonary Embolism—dilated RV and IVC,

visible thrombus in RV/PA

– Pericarditis with effusion—pericardial effusion

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Aortic Dissection

� An intimal tear in the aorta causing blood

tracking through the aortic media, creating

complications

� Classifications:

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Aortic Dissection

� High mortality if untreated: 1-2%/hour over

1st 24-48 hours

� Only 43% of confirmed patients with AD

were suspected by EP and up to 28% was

diagnosed postmortem

� CXR: normal in 12-18% and only 10-18%

have widened mediastinum

Am J Emerg Med 2000 18: 46-50

J Emerg Med 2007 32(2): 191-196

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Aortic Dissection

� Sensitivity for aortic dissection

– Transthoracic Echo: 70%, mainly for proximal

disease

– Transesophageal Echo: near 100%

Am H J 1992 124(2): 541-3

Circulation 1992 85(2): 434-46

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Aortic Dissection� Transthoracic ECHO features:

– Mainly for proximal aortic dissection

– Detection of intimal flap

– Dilated Ao and AR

– Pericardial effusion

Intimal flap at LVOTIntimal flap at LVOT

Zoom up

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Aortic Dissection

Apical Long Axis view showing Severe AR by CFM

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� with cardiac temponade

Aortic Dissection

Pericaradial effusion with collapsed RV Dialted Ao=4.1cm [normal<3.5cm]

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Thank You

ANY QUESTION??