Learning objectives
Key terminology
Pre-procedure considerations

Transesophageal echocardiography

Transesophageal echocardiography (TEE) is an invasive procedure that involves imaging of the heart using a small transducer mounted on the tip of a gastroscope. The gastroscope is inserted through the mouth, then into the esophagus, and advanced toward the patient's stomach. The ultrasound beam is directed through the esophageal wall toward the heart.

Since the probe is located close to the heart, a higher scanning frequency can be used, producing images of a higher resolution. The images are usually clearer than images acquired by transthoracic echocardiography (TTE), since there is no ultrasound signal attenuation, as often occurs when the sound passes through the lungs during transthoracic imaging.

TEE is typically used in patients where transthoracic imaging is suboptimal (eg, obesity or pulmonary disease), or there is a clinical requirement for further information. TEE can be used during surgical cardiac procedures (eg, cardiac catheterization).

The use of a multi-plane probe allows all modalities (eg, M-mode, spectral, and color flow Doppler) to be obtained.

Certain cardiac conditions are better visualized and assessed using TEE:

• valvular heart disease
• thrombi
• intracardiac masses
• aortic dissection or aortic aneurysm 
• prosthetic heart valves
• atherosclerosis 
• cardiomyopathy 
• congenital heart disease (eg, atrial septal defect, patent foramen ovale)
• pericarditis

Transesophageal ultrasound simulation

Transthoracic ultrasound simulation

We acknowledge that there may be variations in the technique presented.
You should perform this procedure under the supervision of an appropriately skilled supervisor until you are confident and competent enough to do it on your own.
Before using any medication or equipment in this procedure, please read the approved product information for instructions, contraindications, adverse effects, and warnings. Familiarize yourself with the equipment. The equipment or medication available to you may differ from what is used in this demonstration. You must inquire with a supervisor or instructor if there are variations or questions related to the equipment, medication, or procedures.

Ensure that all the equipment is plugged in and turned on before beginning with the patient. Typically, all equipment including ultrasound machines and power beds is turned off but left plugged in at the end of the day. The power bed should be turned on and left on during the day. This keeps the bed operational.

Turn on the computer system, workstation, and printer. Select the storage media.

Ensure that there is adequate linen on the bed, and a good supply of additional linen and cloths.

Prepare and set up the necessary equipment for the physician:

• medications (ie, sedative, prophylaxis, antibiotics)
• equipment for intravenous access
• local anesthetic
• lubricants
• transesophageal probe 
• bite block
• drying agent used to minimize oral secretions and therefore aspiration

Obtain a sonographer's TEE worksheet on which to write the examination finding.

Check that the crash cart is fully stocked with cardiopulmonary resuscitation (CPR) equipment and emergency drugs. This task is usually performed by the attending nurse; however, there may be certain situations that necessitate that the sonographer completes the task.

Ensure that oxygen and suctioning equipment is available and ready for use.

Elevate the head of the bed; this position is more comfortable for the patient, and it also helps avoid aspiration.

The attending nurse would check that the pulse oximeter and blood pressure monitoring equipment is available and ready for use.

Perform the standard introductions with the patient.

Confirm the patient's details (name and date of birth) and clinical information.

Check that the patient has been fasting for 6 hours.

Obtain a brief medical history:

• pain: its location and duration, if present
• history of cardiac surgery or interventions 
• history of echocardiography procedures, pathology, or disease
• any previous relevant tests, or imaging procedures
• height and weight, if not provided
• history of allergies and drug reactions
• past history of bleeding disorders
• any difficulty in swallowing
• current medical problems

The physician will explain the procedure to the patient, outlining:

• how the procedure will be performed
• how long the procedure is expected to take
• potential risks and side effects

The physician will also:

• obtain signed informed consent
• administer IV conscious sedation to assist with relaxation
• anesthetize the pharynx by spraying local anesthetic (eg, lidocaine) into the back of the throat, to suppress gag reflex
• administer prophylactic antibiotics, although not commonly used

Enter the patient details into the ultrasound machine.

Direct the patient to a changing room where they can dress in the appropriate gown or other attire for the examination. Instruct the patient to remove all clothing except for their underwear and to put on a gown. If the patient is female, the bra should also be removed.
If the patient has dentures, removable orthodontic plates, or glasses, these will need to be removed prior to commencing the procedure.

The attending nurse will:

• insert an intravenous (IV) line 
• insert nasal tube for the administration of oxygen, if required

Explain to the patient that they will be asked to swallow as the TEE probe is inserted, as this will assist the intubation process.

Ask the patient to lie down on the bed and to roll over onto their left side, into the left lateral decubitus position. Place a wedge support between the patient's knees (for comfort) and raise the sides of the ultrasound bed for the patient's safety.

Left lateral
decubitus position

Expose the chest area.

Apply the 3-lead ECG electrodes (and wires) to the chest wall in the appropriate positions.

ECG lead placement

Ensure that the ECG cable is securely plugged into the ultrasound machine. Observe the ECG tracing to ensure that a clear ECG signal is obtained, with a positive R wave of reasonable size. Adjust the ECG gain, or reposition the ECG leads, if necessary.

An attending nurse will closely monitor the patient's vital signs during the procedure.

Take standard precautions.

Place the ultrasound machine at the head of the patient and to the left, so the physician can observe both the ultrasound monitor and the TEE gastroscope.

Sit facing the keyboard to operate the ultrasound machine.

The attending nurse is usually to the right of the physician at the head of the bed, monitoring the patient's vital signs.

Patient and machine
positioning

Plug in the probe lead and selects the TEE probe button on the ultrasound machine.

Transesophageal
echocardiography
probe

Confirm the correct transducer selection on the ultrasound machine, and select the appropriate preset for adult TEE echocardiography.

The physician places a bite guard (bite block) in the patient's mouth; this prevents damage to the probe and instructs the patient to flex their neck.

Surgical gel (lubricant) is applied to the tip of the TEE probe.

The physician inserts the slightly flexed TEE probe through the bite guard, instructing the patient to swallow as the probe is advanced down the pharynx, into the esophagus. The tube is advanced slowly and smoothly, until the tip is next to the heart (approximately 30 to 35 cm from the level of the incisor teeth).

Provide the patient with the necessary reassurance to ensure that they remain calm during the intubation process.

During the procedure, the patient's vital signs are monitored by the attending nurse.

The orientation of the imaging planes in TEE are displayed in degrees. The transducer plane can be rotated 180 degrees. The transducer tip of the scope can also be flexed left or right from the neutral position, to gain the long or short axis views of the heart.

A four-chamber view is obtained by the physician, at the level of the mid-esophagus (30 to 40 cm from the incisors). The physician obtains this view by pressing the "button" on the shaft of the scope, to achieve the required degree of rotation.

The 0 degree view is similar to the apical four-chamber view in transthoracic echocardiography (TTE) and gives an excellent view of the atria, mitral, and tricuspid valves. This is important in cases where the prosthetic valve replacements demonstrate acoustic shadowing across the atria, disrupting the view of the atria in TTE ultrasound.

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Four-chamber TEE
2D ultrasound

If color Doppler is indicated, press the color Doppler button, adjust and align the color box over the mitral valve and/or tricuspid valve, and capture the color loop.

A short axis view of the aortic valve, at the level of the upper esophagus (20 to 25 cm from incisors), is obtained in the 45 degree view. The physician obtains this view by pressing the "button" on the shaft of the scope to achieve the required degree of rotation. This view is similar to the parasternal short axis (PSSA) of the aortic valve in TTE.

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Short axis mid-esophageal
TEE 2D ultrasound

If color Doppler is indicated, press the color Doppler button, adjust and align the color box over the aortic valve, and capture the color loop.

A two-chamber view of the left ventricle and left atrium is obtained in the 90 degree view. Transducer tip movement, as well as rotation of the transducer beam, is required at the mid-esophagus level (30 to 40 cm from the incisors) to obtain this view. The physician obtains this view by pressing the "button" on the shaft of the scope, to achieve the required degree of rotation. This is similar to the apical two-chamber view in TTE.

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Two-chamber
mid-esophageal
TEE 2D ultrasound

If color Doppler is indicated, press the color Doppler button, adjust and align the color box over the mitral valve, and capture the color loop.

A long axis view of the left ventricle outflow tract (LVOT), aortic valve, and left atrium, at the mid-esophagus level (30 to 40 cm from the incisors) is obtained in the 135 degree view. This view has similarities with the parasternal long axis (PSLA) view in TTE.

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Long axis mid-esophageal
TEE 2D ultrasound

If color Doppler is indicated, press the color Doppler button, adjust and align the color box over the LVOT and aortic valve, and capture the color loop.

The longitudinal TEE views are taken in the longitudinal plane of the body, at the mid-esophagus level (30 to 40 cm from the incisors). The beam position is set at 90 degrees, and using the dial on the shaft, the physician moves the tip of the probe from the patient's left to the right.

A long axis view of the mitral valve and left ventricular outflow tract (LVOT) is obtained.

Mid-esophageal
long axis

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Long axis mid-esophageal
TEE left rotation

If color Doppler is indicated, press the color Doppler button, adjust and align the color box over the LVOT and/or the mitral valve, and capture the color loop.

A long axis view of the right ventricle and right ventricular outflow tract (RVOT) is obtained.

Mid-esophageal long
axis right ventricular
outflow tract

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Long axis mid-esophageal
TEE right rotation

If color Doppler is indicated, press the color Doppler button, adjust and align the color box over the RVOT, and capture the color loop.

A long axis view of the aortic valve and the ascending aorta is obtained. The physician obtains this view by pressing the "button" on the shaft of the scope, to achieve the required degree of rotation.

Mid-esophageal long
axis aortic valve
and ascending aorta

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Long axis mid-esophageal
TEE neutral

If color Doppler is indicated, press the color Doppler button, adjust and align the color box over the aortic valve and ascending aorta, and capture the color loop.

The transducer tip is moved to the fundus of the stomach (40 to 45 cm from the incisors). These views demonstrate the short and long axis planes of the heart.

A short axis view of the left and right ventricles is obtained by the physician.

Transgastric short
left ventricle

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Short axis
transgastric TEE

A long axis view of the left ventricle is obtained. The physician obtains this view by pressing the "button" on the shaft of the scope to achieve the required degree of rotation.

Transgastric long
axis

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Long axis transgastric
TEE 90 degree

A long axis view of the LVOT and aortic valve is obtained. The physician obtains this view by pressing the "button" on the shaft of the scope, to achieve the required degree of rotation.

Transgastric long
axis deep

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Long axis transgastric
TEE 120 degree

If color Doppler is indicated, press the color Doppler button, adjust and align the color box over the LVOT and aortic valve, and capture the color loop.

The tip of the gastroscope is moved to just above the level of the left atrium (between the mid-esophageal and the transgastric level).

A long axis view of the main pulmonary artery and both proximal right and left pulmonary artery branches is obtained by the physician.

Long axis atrial level

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Long axis TEE
left atrial level

A long axis view of the heart is obtained, with the probe in the mid-esophageal position (30 to 40 cm from the incisors). The probe is then slightly withdrawn, to obtain the left atrial appendage view.
Normal trabeculations can be noted in this view.

Long axis atrial
level 90 degree

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Left atrial
appendage TEE

The close proximity of the esophagus and the aorta allows the best visualization of the thoracic aorta. The descending thoracic aorta is situated to the patient's left side. The gastroscope is at the mid-esophageal level (30 to 40 cm from the incisors).

A short axis view of the descending thoracic aorta is obtained by the physician. Excellent visualization of the intima can be obtained.

Short axis
descending aortic

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Short axis mid-esophageal
TEE descending aortic

If color Doppler is indicated, press the color Doppler button, adjust and align the color box over the descending thoracic aorta, and capture the color loop.

A long axis view of the descending thoracic aorta is obtained. The physician obtains this view by pressing the "button" on the shaft of the scope, to achieve the required degree of rotation.

Long axis
descending aortic

Sonographer instruction:
Capture the 2D loop as per standard protocol.

Long axis mid-esophageal
TEE descending aortic

If color Doppler is indicated press the color Doppler button, adjust and align the color box over the descending thoracic aorta, and capture the color loop.

The probe is removed from the patient's esophagus, once all imaging and assessment has been completed.

Post-procedure considerations

Pathology

A) Subaortic valve disease

i) Aortic dissection

An aortic dissection is a tear in the aortic wall allowing blood to enter the layers of the wall, usually the intima and media layer. A hematoma can form in the tear and surrounding wall. A false lumen is created as the hematoma forms in the layer. Intimal tissue separates the real lumen and this false lumen, and is referred to as the intimal flap. The presence of a hematoma reduces the space through which blood can flow on to the arteries. In some cases, all three layers of the aortic wall are dissected, resulting in enormous and prompt blood loss that can quickly result in death. Hypertension, valve disorders (ie, aortic stenosis, bicuspid aortic valve), and connective tissue disorders (ie, Marfan's syndrome) are known causes of dissection.

Aortic dissection

Clinical signs and symptoms

• chest pain
• dyspnea 
• neck or jaw pain

Transesophageal echocardiography objectives
An echocardiogram is performed to further evaluate the size and site of the mobile intimal flap.

Transesophageal echocardiography findings

• 2D
  • dilated aorta
  • intimal flap
  • false lumen (due the presence of a hematoma)
  • aortic valve leaflet prolapse
• Color Doppler
  • reverse flow in false lumen during ventricular diastole
  • forward flow in true lumen during ventricular systole
  • possible aortic regurgitation
  • possible mitral regurgitation

ii) Aneurysmal disease

Aneurysmal disease usually occurs where there is a weakness in the aortic wall. Blood flowing through the aorta (at high pressure) causes the weak or diseased area to increase in length and diameter (bulge). Continuous pressure on this weakened area causes the bulge to grow in size. Pain may be experienced, but this is usually when the disease is in its advanced state. Occlusion or rupture of aneurysms is the complication of concern, as rupture can rapidly result in death from hemorrhage.

Typically, the aneurysm is classified according to its location:

• abdominal aortic aneurysm (AAA) - most common
• thoracic aortic aneurysm (ascending, aortic arch, or descending)
• aortic root (aneurysm of sinus of Valsalva) - rare

Systemic hypertension, atherosclerosis, trauma, infection (ie, infective endocarditis), and connective tissue disorders (ie, Marfan's syndrome) are all known causes of aneurysmal disease.

Clinical signs and symptoms

• asymptomatic
• chest pain
• back pain
• intense abdominal pulse
• nausea
• vomiting
• leg lesions near ankle (AAA)
• hoarse voice

Transesophageal echocardiography objectives
An echocardiogram is performed to further evaluate the size of the dilated aorta and its location in relation to other vasculature.

Transesophageal echocardiography findings

• 2D
  • aortic dilation
• Color Doppler
  • aortic regurgitation

Quantification of aortic root and ascending aortic measurements

B) Native valve disease

i) Mitral stenosis

Mitral stenosis is narrowing or constriction of the mitral valve orifice and thickening of the mitral leaflets. This thickening may include the chordae tendinae. The condition may be congenital or acquired, and restricts the blood flow from the left atrium to the left ventricle during diastole.

The left atrium enlarges as it pumps blood into the left ventricle against resistance. Because blood is unable to flow efficiently through the heart, back pressure can result in pulmonary edema. When the mitral valve orifice is reduced from approximately 5 cm² to 2 cm², the patient usually experiences symptoms.

Clinical signs and symptoms

• exertional dyspnea 
• syncope 
• pulmonary congestion
• diastolic murmur
• palpitations
• arrhythmias
• symptoms of heart failure
• asymptomatic, if the condition is mild

Transesophageal echocardiography objectives
An echocardiogram can be used to further evaluate the severity of the narrowing.

Transesophageal echocardiography findings

• 2D
  • degenerative annular calcification of either one or both of the valve leaflets
  • leaflet thickening with restricted movement
  • fusion of the anterior and posterior leaflets causing a reduced opening of the mitral valve leaflets 
  • a "hockey stick" appearance, especially to the anterior mitral valve leaflet when mobile (also known as "elbowing")
  • presence of left atrial or left atrial appendage thrombus 
• Color Doppler 
  • mitral regurgitation
  • tricuspid regurgitation
  • turbulent color flow through narrowing

ii) Aortic stenosis

Aortic stenosis is a narrowing of the aortic valve orifice, which increases resistance to blood flow from the left ventricle to the aorta during systole.

Aortic stenosis is characterized by the degeneration, calcification, and reduced motion of the leaflets, with commissural fusion at the junction of some leaflets. Aortic stenosis may be age-related, pathological (syphilis), or congenital (a bicuspid aortic valve).

Long-term effects include symmetrical left ventricular hypertrophy, and eventually, left ventricular dysfunction. The thicker walls reduce the filling space inside the ventricle, so less blood is pumped out. Patients may report exercise-related fainting, but their resting cardiac output could appear normal. Eventually, the coronary arteries cannot adequately supply the thickened and overworked heart muscle, so myocardial ischemia, then heart failure, can result.

Clinical signs and symptoms

• exertional dyspnea
• exercise-related syncope 
• angina pectoris
• palpitations 
• ejection systolic murmur
• symptoms of congestive heart failure 
• sudden death in hyperdynamic or increased flow states (ie, heavy exercise)
• asymptomatic, if the condition is mild

Transesophageal echocardiography objectives
An echocardiogram can further assess the severity and location of the stenosis.

Transesophageal echocardiography findings

• 2D
  • leaflet thickening with restricted motion
  • leaflet retraction
  • calcification
  • abnormal aortic valve anatomy (eg, a unicuspid, bicuspid, asymmetric tricuspid, or quadricuspid valve visualized)
  • possible enlargement of the aortic root
• Color Doppler
  • turbulent high velocity dense jet (typically located centrally, at the right coronary cusp, at the left coronary cusp, or in non-coronary cusp commissures)
  • location of the stenosis - subvalvular, valvular, or supravalvular (coarctation)
  • co-existence of aortic insufficiency
  • concurrent mitral regurgitation (common in the older population)

iii) Tricuspid stenosis

Tricuspid stenosis is a restriction of blood flowing into the right ventricle from the right atrium, due to the tricuspid orifice becoming narrowed.

The right atrium may become enlarged, and blood is less effectively pumped to the pulmonary vasculature. Tricuspid stenosis is frequently accompanied by tricuspid regurgitation and mitral valve stenosis.

Clinical signs and symptoms

• fatigue
• abdominal pain in the right upper quadrant (related to liver enlargement)
• sensation of "flutter" in the neck 
• prominent jugular vein
• asymptomatic, if mild

Transesophageal echocardiography objectives
Echocardiography can further assess the severity of the narrowing.

Transesophageal echocardiography findings

• 2D
  • thickening tricuspid valve leaflets with restricted motion (especially at tips and chordae tendinae) 
  • diastolic "doming" of the valve visualized 
  • leftward bowing of the interatrial septum toward the left atrium
• Color Doppler
  • turbulent flow
  • tricuspid inflow jet demonstrated on color Doppler; characterized by a candle flame-shaped jet with a mosaic center (like mitral stenosis)
  • flow convergence proximal to leaflets demonstrated on color Doppler

iv) Pulmonary stenosis

Pulmonary stenosis is a congenital abnormality where blood flow through the pulmonary valve is restricted. Volume and pressure overload of the right ventricle occur, causing right ventricular dilation. The condition may also be associated with exposure to rubella in utero, particularly during the first trimester. The patient might not show symptoms for years, however.

Clinical signs and symptoms

• reduced exercise tolerance
• cyanosis
• peripheral edema
• systolic heart murmur

Transesophageal echocardiography objectives
Echocardiography will further assess the severity and location of the narrowing.

Transesophageal echocardiography findings

• 2D
  • thickened pulmonary valve leaflets with restricted opening
  • post-stenotic dilation of the main pulmonary artery
• Color Doppler
  • turbulent jet leading into the pulmonary artery (on color Doppler)
  • subvalvular or supravalvular stenotic lesion tricuspid regurgitation

C) Prosthetic valve assessment

i) Aortic valve replacement

TEE can be used to further evaluate the function of the prosthetic valve replacement.

The material the grafts are made from can result in artifacts, acoustic shadowing, and increased echogenicity.
Biological, bioprosthetic, and mechanical valves are used for aortic valve replacements.

Clinical signs and symptoms

• valvular dysfunction
• valvular regurgitation

Transesophageal echocardiography objectives
The objective for the imaging the prosthetic valve is to establish the following details:

• appearance and motion of the prosthetic valve
• leaflet or occluder motion
• whether the leaflets are thickened (in the case of bioprosthetic/biological valves)
• abnormal motion of the valve ring 
• suspected valvular/perivalvular abscess
• suspected intracardiac thrombus (especially in the atria, which may be difficult to visualize due to acoustic shadowing of the prosthetic valve)

Transesophageal echocardiography findings

• 2D
  • increased thickened/calcified leaflets
  • restricted leaflet motion
  • presence of thrombus and vegetations
  • dehiscence
    • This is visualized by the excessive rocking motion at the point of the sewing ring.
• Color Doppler
  • flow direction specific for disc type, using color Doppler
  • more accurate in assessing the severity of regurgitation perivalvular leaks
  • high velocity jet obtained with color through the dehiscence site

ii) Mitral valve replacement

TEE can be used to further evaluate the function of the prosthetic valve replacement.

The material the grafts are made from can result in artifacts, acoustic shadowing, and increased echogenicity.

Bioprosthetic and mechanical valves are used for mitral valve replacements.

Clinical signs and symptoms

• valvular dysfunction
• valvular regurgitation

Transesophageal echocardiography objectives
The objective for the imaging the prosthetic valve is to establish the following details:

• appearance and motion of the prosthetic valve
• leaflet or occluder motion
• whether the leaflets are thickened (in the case of bioprosthetic/biological valves)
• abnormal motion of the valve ring 
• suspected valvular/perivalvular abscess
• suspected intracardiac thrombus (especially in the atria, which may be difficult to visualize due to acoustic shadowing of the prosthetic valve)

Transesophageal echocardiography findings

• 2D
  • increased thickened/calcified leaflets in biological/bioprosthetic valves
  • restricted leaflet motion in biological/bioprosthetic valves
  • reduced occluder motion, or stuck motion in mechanical valves
    • If the artifact is moving, it means the occluder is moving. The sonographer can use the artifact to their advantage.
  • presence of thrombus and vegetations
  • dehiscence (bursting open of the suture line) or abscess of the valve ring 
    • This is visualized by the excessive rocking motion at the point of the sewing ring.
  • pseudoaneurysm of the valve bed
• Color Doppler
  • flow direction specific for disc type, using color Doppler
  • more accurate in assessing the severity of regurgitation perivalvular leaks
  • high velocity jet obtained with color through the dehiscence site

D) Intracardiac tumors

i) Myxoma

A myxoma is a benign cardiac tumor usually found in patients 30 to 60 years old. It is the most common of the cardiac tumors, and is found more often in female patients. Myxomas predominantly form in the left atrium, but can also be found in the right atrium and also the ventricles. They may develop from embryonic cells in the endocardium. The tumor grows on a stalk (attached to the interatrial septum) and swings in the blood flow, causing intermittent obstruction of blood flow through a valve.

Myxoma

Clinical signs and symptoms

• fever
• rash
• embolism
• heart failure
• dizziness
• anemia
• acute pulmonary edema

Transesophageal echocardiography objectives
An echocardiogram is used to assess the location of the attachment of the intracardiac mass.

Transesophageal echocardiography findings

• 2D 
  • attachment point of the myxoma is clearly seen
  • echotexture of the mass may demonstrate central necrosis or hemorrhage
  • damage to valve clearly demonstrated, if present
  • atrial tumor may prolapse into the ventricle during diastole
• Color Doppler
  • space occupying tumor causes a mitral or tricuspid stenosis by narrowing the inflow
  • mitral regurgitation

ii) Papillary fibroelastoma

A papillary fibroelastoma (papilloma) is usually found in patients who are over the age of 60 years, and is the third most common primary benign cardiac tumor. Tumors are frequently located on the mitral or aortic valves and said to resemble a sea anemone.

The tumor is attached by a pedicle to the endocardial surface of the valves. It can also be located in the left ventricular outflow tract (LVOT), papillary muscles, or chordae tendinae.

Papillary fibroelastoma

Clinical signs and symptoms

• syncope, due to valvular obstruction
• chest pain, due to valvular obstruction 
• myocardial infarction, due to embolism
• stroke, due to embolism

Transesophageal echocardiography objectives
An echocardiogram is used to evaluate the intracardiac mass and its location.

Transesophageal echocardiography findings

• 2D 
  • pre-operative assessment, to accurately locate the pedunculated mass
  • echotexture assessment of the mass
  • echo-dense mass is small and mobile
  • stork-like attachment to the endocardium
  • usually < 1 cm in size
  • usually found on the endocardial surfaces of the aortic and mitral valves
  • vegetation 
• Color Doppler
  • significant regurgitation or stenosis of the aortic or mitral valves

iii) Lipoma

Intracardiac lipomas predominantly affect adults. Lipomas are composed of adipose tissue and usually located in the left ventricle, right atrium, or atrial septum (causing hypertrophy and arrhythmias). The cardiac valves are not usually involved.

Clinical signs and symptoms

• asymptomatic
• arrhythmia
• dyspnea due to obstruction
• pericardial effusion

Transesophageal echocardiography objectives
An echocardiogram is used to evaluate the location of the intracardiac mass.

Transesophageal echocardiography findings

• 2D 
  • Well-circumscribed tumor
  • solitary mass
  • mass may be located intramuscular, subendocardial, subepicardial, or epipericardial
  • thickened interatrial septum is demonstrated in lipomatous hypertrophy
• Color Doppler
  • significant regurgitation or stenosis

iv) Fibromas

Cardiac fibromas typically affect children and are referred to as a congenital. A single round tumor is usually located within the myocardium of the left ventricle, interventricular septum, or right ventricle, and on the heart valves. Fibromas may develop from the heart's fibrous tissue cells.

Clinical signs and symptoms

• heart failure
• arrhythmias
• sudden death
• asymptomatic

Transesophageal echocardiography objectives
An echocardiogram is used to evaluate the location of the myocardial mass.

Transesophageal echocardiography findings

• 2D 
  • solitary mass seen in the myocardial wall
  • usually visualized in the myocardium
  • sites include the anterior wall of the left ventricle, interventricular septum, or right ventricle
  • vary in size from 3 to 10 cm
• Color Doppler
  • significant regurgitation or stenosis

v) Angiosarcomas

Angiosarcomas are the most common of the primary malignant cardiac tumors (sarcomas). They are usually found in the right side of the heart (usually the right atrial wall or pericardium) and tend to affect adult males.

Angiosarcoma

Clinical signs and symptoms

• dyspnea
• murmur
• right heart failure
• pericardial effusion 
• cardiac tamponade

Transesophageal echocardiography objectives
An echocardiogram is used to evaluate the location of the cardiac mass.

Transesophageal echocardiography findings

• 2D 
  • mass seen in the atrial wall and pericardium
  • pericardial effusion
• Color Doppler
  • significant regurgitation or stenosis

vi) Metastatic disease

Metastatic disease can result from the spread of a primary tumor (ie, breast, lung, and renal carcinoma, soft-tissue sarcoma, or melanoma). The heart's myocardium is usually where the metastasizing tumor will site itself.

Clinical signs and symptoms

• enlarged heart
• tamponade
• tachycardia
• heart block
• arrhythmias
• sudden heart failure

Transesophageal echocardiography objectives
An echocardiogram is used to evaluate the extent of the disease.

Transesophageal echocardiography findings

• 2D 
  • pericardial thickening, or caking
  • myocardial thickening
  • mass protruding into a cardiac chamber
  • tumor thrombus mass within the lumen of the IVC from renal cell carcinoma
• Color Doppler
  • significant regurgitation or stenosis

vii) Carcinoid heart disease

Carcinoid heart disease is a metastatic disease. A primary tumor, usually from the gastrointestinal system (ie, appendix or ileum), metastasizes to the heart endocardium or heart valve. The right side of the heart is usually affected. Superficial plagues form on the endocardium of the heart chambers. Fibrous deposits form on the valves, causing and valvular disease (ie, tricuspid regurgitation/stenosis, pulmonary regurgitation). Carcinoid tumors secrete high levels of serotonin and correlate with the severity of the disease.

Clinical signs and symptoms

• flushing of the face
• diarrhea
• death
• right-sided heart failure
• right-side murmurs
• ascites
• dyspnea

Transesophageal echocardiography objectives
An echocardiogram is used to evaluate the extent of the disease.

Transesophageal echocardiography findings

• 2D
  • thickened, retracted, and rigid tricuspid and/or pulmonary valve leaflets
  • coaptation of the leaflets is reduced
  • pulmonary cusps may be stuck to the pulmonary artery walls
  • other valve adhesions may also be seen
• Color Doppler
  • tricuspid regurgitation (most common)
  • tricuspid stenosis
  • pulmonary regurgitation
  • pulmonary valve stenosis
  • mitral regurgitation

E) Congenital heart disease

i) Patent foramen ovale

A patent foramen ovale (PFO) is a variant of an atrial septal defect that occurs due to incomplete closure of the atrial septum. Normally, the septum primum and septum secundum fuse after birth, and get completely sealed within 1 year. If this does not happen, a patent opening between the left and right atria persists. This has the potential for blood shunting from right to left, especially in combination with conditions that increase right atrial pressure.

Patent foramen ovale

The PFO size will increase with age as the heart grows, and the atrial septum may become abnormally mobile or form an aneurysm. Here, hemostasis and clot formation may take place, which can result in an embolic event (like a stroke) when blood shunting is induced. PFO is very common and occurs in 25 to 30% of the adult population. However, it is only detected in 10 to 15% of the population.

Clinical signs and symptoms

• usually asymptomatic
• migraine
• transient ischemic attack (TIA) or stroke, due to paradoxical emboli across the shunt
• sleep apnea
• cyanosis, upon breath-holding or crying
• neurologic decompression sickness, in scuba divers

Transesophageal echocardiography objectives
An echocardiogram is used to evaluate the size and location of the defect.

Transesophageal echocardiography findings

• 2D
  • possibly an interatrial flap
  • no other atrial septal defect
  • possibly aneurysmal dilation of the interatrial septum
• Color Doppler
  • "flame of color" in the middle of the interatrial septum
  • right-to-left shunt
  • no flow across the shunt may be visible with color Doppler, when pulmonary pressure is not adequate enough to force the flap open 
• Saline contrast technique

ii) Atrial septal defect

An atrial septal defect (ASD) refers to the presence of an abnormal opening in the interatrial septum. Before birth, a shunt between the atria (through the foramen ovale) is functional, and an ASD is thus not significant at that stage. However, after birth, the interatrial septum should be completely closed to separate the atria. In case of an ASD, a left-right shunt occurs due to the higher pressure in the left atrium. As a result, high-oxygen blood mixes with low-oxygen blood in the right atrium.

Atrial septal defect

Atrial septal defects are subdivided according to the location of the defect:

• ostium secundum defect 
• ostium primum defect 
• sinus venosus defect

ASDs are common and occur approximately twice as often in females than in males (see reference). The majority of small (< 8 mm) ostium secundum defects close spontaneously within 1.5 years after birth (see reference). Closure of ostium secundum defects during adulthood, and spontaneous closure of ostium primum and sinus venosus defects, is unlikely.

Symptoms usually do not arise during childhood, but become evident with increasing age or physiological changes (ie, pregnancy). Most defects are detected during adulthood, and the majority is diagnosed when the patient reaches the age of 50. Mild symptoms may be controlled with medication, but more severe symptoms require surgical closure of the defect.

Clinical signs and symptoms
Symptoms vary and depend on the size of the defect and the shunt.

• frequently asymptomatic during infancy, childhood, and young adulthood
• dyspnea
• fatigue
• reduced exercise tolerance
• peripheral edema
• atrial arrhythmias
• palpitations
• syncope

Transesophageal echocardiography objectives
An echocardiogram is used to evaluate the size and location of the defect.

Transesophageal echocardiography findings

• 2D
  • a defect in the interatrial septum
  • usually a small left atrium
  • main pulmonary artery and pulmonary branch dilatation
  • "clapping of hands" defect; indicates a cleft mitral valve, in case of an ostium primum defect
  • mitral valve prolapse, in case of an ostium secundum defect
• Color Doppler
  • left-to-right flow across the defect 
  • turbulent flow in the pulmonary artery
  • tricuspid regurgitation 
  • pulmonary regurgitation
  • possibly, pulmonary stenosis
  • mitral regurgitation, if a cleft mitral valve is present
• Saline contrast technique 
  • the presence, location, and size of an atrial septal defect
  • the presence of a pulmonary arteriovenous fistula

iii) Ventricular septal defect

A ventricular septal defect (VSD) refers to the presence of an abnormal opening in the interventricular septum. The defect is caused by incomplete growth or fusion of the septum.
As a result, blood shunts from the left to the right ventricle, due to the pressure difference between them. High-oxygen blood from the left ventricle mixes with low-oxygen blood from the right ventricle, and recycles through the pulmonary circulation. This can lead to an overload of the left ventricle and pulmonary circulation, and circulation of less oxygenated blood through the body.

Ventricular septal
defect

Ventricular septal defects are subdivided according to the location of the defect:

• perimembranous defects (70 to 80% of all VSDs) (see reference)
• trabecular muscular defects (5 to 20% of all VSDs) (see reference)
• outlet defects (5 to 7% of all VSDs) (see reference)
• inlet defects (5 to 10% of all VSDs) (see reference)

The magnitude of a shunt, its impact on the circulation, and the resulting symptoms depend on the size of the defect and the resistance of the pulmonary vasculature. Small defects only cause minor left-to-right shunts (Qp/Qs < 1.75:1) (see reference) and do not affect pulmonary circulation. Larger defects, and the resulting larger shunts (Qp/Qs > 2:1) (see reference), cause an overload pattern in the left ventricle and hypertrophy of the right ventricle. Furthermore, they cause hypertension and elevated resistance of the pulmonary artery. Over time, the increased vascular resistance in the lungs causes a reversal of shunt direction (becoming a right-to-left shunt), leading to Eisenmenger syndrome, and possibly, heart failure and death.

VSDs are common and are often diagnosed in infants, and when the defect is large, within the first few weeks of life. Maternal drug and alcohol abuse increase the fetal risk of VSD. The defect may occur isolated or in conjunction with other cardiac anomalies. Small defects do not cause symptoms and often close spontaneously in the first few years after birth. Persistent small defects usually do not require medical or surgical intervention. Larger defects do not close spontaneously and, even when asymptomatic, require surgical closure.

Clinical signs and symptoms
Symptoms vary and depend on the size of the defect and the shunt.

• asymptomatic, in case of a small VSD
• chest pain
• syncope
• cyanosis
• clubbing
• tachypnea or some respiratory difficulty
• symptoms of heart failure
• symptoms of Eisenmenger syndrome

Transesophageal echocardiography objectives
An echocardiogram is used to evaluate the size and location of the defect.

Transesophageal echocardiography findings

• 2D
  • a defect in the interventricular septum main pulmonary and pulmonary branch dilatation
  • aortic valve prolapse
• Color Doppler
  • high, turbulent blood flow across the defect
  • aortic regurgitation
  • mitral regurgitation
  • tricuspid regurgitation
• Saline contrast technique 
  • presence, location, and size of the ventricular septal defect

Stress echocardiography is a type of transthoracic echocardiography, where the heart is imaged under simulated exercise conditions. Since many patients' symptoms are apparent only with exertion, this induces the development of symptoms and may identify abnormalities that are not apparent at rest. Increased heart rate (cardiac stress) may be achieved through exercise (eg, on a treadmill, supine bicycle, stair step), or non-exercise stress (eg, a medication [dobutamine, dipyridamole] that simulates the effect of exercise by speeding up the heart rate and increasing the force of each cardiac contraction).

Exercise stress echocardiography involves the patient exercising according to a standard exercise protocol on a treadmill, with ECG and blood pressure monitoring. The difficulty of the exercise is gradually increased (using speed and gradient). This is the preferred choice for exercise stress echocardiography, as it best mimics real-life ischemia. However, exercise stress echocardiography is difficult to perform because of the need to transfer the patient to the bed as soon as possible after exercise stops, and many patients find the technique difficult.

Exercise stress
echocardiography

Dobutamine stress echocardiography is an alternative to exercise echocardiography that involves a gradual increase in the dose of dobutamine infused, to gradually increase heart rate. During the test, monitoring of ECG and blood pressure is performed. Dobutamine is often used in patients who cannot exercise adequately, or for the assessment of myocardial viability. A radiotracer is injected into the patient during the simulated exercise, and images of the patient's coronary arteries are taken, to be compared with images of the arteries while at rest.

Exercise stress testing is commonly performed using a treadmill as this method is non-invasive and a simple way to increase the heart rate. Physical exercise increases the cardiac output (CO), heart rate (HR), and blood pressure (BP).

In the presence of coronary artery disease (CAD), otherwise known as ischemic heart disease (IHD), there is a decrease or reduction in the blood flow through the coronary arteries, causing myocardial ischemia. This manifests as changes on the ECG, particularly the ST segment and/or symptomatic clinical changes.

The resulting myocardial ischemia is shown as a new regional wall motion abnormality on the 2D images in an echocardiography.

image name

It is common to reduce or stop beta blockers for 72 hours before the test; this must be discussed with the physician prior to making the appointment.

On the day of the examination, the procedure is explained to the patient, and written consent obtained. The patient is then directed to a changing room where they can dress in the appropriate attire (running/walking shoes, track pants or shorts, and a front opening gown for women). Men may require appropriate part of the chest hair to be shaved, to ensure that adequate ECG lead contact is attained.

A 12-lead ECG is used in stress echocardiography. Changes in lead placement are made to accommodate the positions of the views (parasternal short axis, parasternal long axis, and apical) required during scanning.

V1 and V2 lead placements are higher, and V3, V4, V5, and V6 are lower.

A full routine resting echocardiogram is performed, to assess the resting left ventricular systolic and diastolic function, valvular, and right heart function. The sonographer acquires a four-chamber, two-chamber, apical long axis, and short axis images.

The patient is then exercised on the treadmill and monitored closely throughout.

The Bruce protocol or a modified version (dependent on the individual's level of fitness) is used to exercise the patient until the absolute or relative endpoints are met.

Once the exercise criteria are met, the patient lies on the ultrasound bed immediately after the treadmill has stopped. The routine 2D stress echocardiography views are obtained as quickly as possible.

The attending physician reviews all the collated information and images. The physician then consults with the patient to explain the findings of the stress echocardiogram.

• a false-positive, non-diagnostic exercise tolerance test
• difficult interpretation of an exercise tolerance test from conduction or repolarization abnormalities
• to determine and assess the extent, location, and significance of the myocardial ischemia for the past and future intervention
• to determine how the physical abnormalities of the heart function under controlled stress
• to determine the reserve in valvular heart disease contractility
• routine or symptomatic assessment to evaluate after revascularization

A normal stress echocardiogram will demonstrate a symmetric, concentric global contraction of the left ventricular myocardium. The myocardial layer thickens when contracted, and the left ventricular chamber size is decreased in systole.

The heart's normal response to exercise is to increase the contractility of the left ventricle, to cope with the increased body requirements to exercise. The ejection fraction and cardiac output increase, and the left ventricular end-systolic and end-diastolic dimensions decrease. This increase/decrease is visualized by side-to-side comparison of resting and exercise 2D images.

The wall motion analysis guide is a very systematic assessment of the myocardium. The normal contractility of each segment is scored as a 1. This indicates a systolic wall-thickening greater than 40%. Anything less than 40% indicated a reduction in contractility.

The standard format of viewing the images is to display them on a dual screen, with the pre-exercise image on the left and the post-exercise image on the right. Each image is selected and placed in a program template available with the ultrasound setup. This allows for direct comparison ease.

Left ventricular wall motion abnormalities and dysfunction of the myocardium is assessed by a number of methods. Each method has a number of sequential steps that must be performed.

• Subjective information
  • "eyeball" assessment of contractility of the myocardium
  • recognize normal contractility versus abnormal contractility
  • score the contractility of each segment
  • recognize regional versus global changes in the myocardium
• Semi-objective information
  • regional wall motion abnormality score or index
• Objective information
  • fractional shortening
  • ejection fraction
  • systolic function
  • diastolic function

Regional wall motion analysis is performed to assess the myocardial wall for abnormal motion, which can occur as a result of coronary artery disease. The assessment uses specific echocardiographic views:

• 2D parasternal long axis
• apical four-chamber 
• apical two-chamber 
• apical long axis
• three views of the left ventricle in the parasternal short axis

The myocardium is divided into 17 segments, which are also used in nuclear medicine imaging. These are subdivided into levels and regions relating to their typical coronary artery supply:

• basal level
• mid level
• apex level

Each segment of the myocardium is assessed for wall motion.

A score (number) is applied to grade the contractility for each segment of the myocardium.

Quantification of wall motion abnormalities is performed using the regional wall motion score index (WMSI). A baseline score is obtained for comparison on further imaging.

A stress exercise radionuclide study is undertaken using two isotopes. Resting images are taken once the patient has been injected with 201-thallium, and the exercise images are taken after the patient has been injected with Tc-Sestamibi. Images are taken in the vertical long axis (VLA), which is similar to the parasternal long axis (PSLA), the horizontal long axis (HLA) which is similar to the apical four-chamber view, and the short axis (SA) which is similar to the parasternal short axis (PSSA) views.

The images at rest and exercise are compared for changes or defects in the uptake of the radionuclide. A defect is visualized as a "cold" spot or reduced uptake during the exercise portion of the exam. This indicates a lack or reduction in blood supply to that part of the myocardium consistent with an infarct or ischemia. Delayed imaging may demonstrate that these "cold" spots have a slower uptake of the isotope and differentiation can be made between infarction and ischemia.

This is the most important difference between the two types of the imaging. Nuclear imaging is good at assessing the diseased myocardium that would be suitable for surgical/interventional revascularization.

References

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