Echocardiography Assessment of Valvular Disease

Course Image
 

Video

The video provides examples of various valvular pathologies.

Anatomy

The anatomy provides 3D, 360-degree rotating images to illustrate the key structures and components of the heart and major vessels. Additional illustrations are provided to illustrate the cross-sectional anatomy of the heart, and heart valves.

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Introduction
Step 1: Mitral valve
1.1 Basic physiology
1.2 Pathology
1.2.1 Mitral stenosis
1.2.2 Mitral regurgitation
1.2.3 Mitral valve prolapse
1.2.4 Flail mitral valve
1.2.5 Mitral annulus calcification
1.2.6 Proximal isovelocity surface area
1.2.7 Mitral valve replacement
Step 2: Aortic valve
2.1 Basic physiology
2.2 Pathology
2.2.1 Aortic stenosis
2.2.2 Aortic regurgitation
2.2.3 Bicuspid aortic valve
2.2.4 Aortic valve prolapse
2.2.5 Idiopathic hypertrophic subaortic stenosis (IHSS)
2.2.6 Aortic valve replacement
Step 3: Tricuspid valve
3.1 Basic physiology
3.2 Pathology
3.2.1 Tricuspid stenosis
3.2.2 Tricuspid regurgitation
Step 4: Pulmonary valve
4.1 Basic physiology
4.2 Pathology
4.2.1 Pulmonary regurgitation
4.2.2 Pulmonary stenosis

Step 1: Mitral valve

1.1. Basic physiology

When the left ventricle relaxes (diastole) the mitral valve opens, allowing oxygen-rich blood in the left atrium to flow into the left ventricle. Initially the flow is rapid (E wave on Doppler echocardiography), then the flow begins to slow. The left atrium contracts (end-diastole) forcing more blood into the left ventricle (A wave); this is also known as atrial kick. The ventricle then contracts (systole), triggering the closure of the mitral valve, preventing blood flowing back into the atrium. Blood in the left ventricle then travels through the aortic valve into the aortic artery.


Mitral valve

1.2. Pathology

1.2.1. 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.


Mitral stenosis


Ultrasound image of
mitral stenosis

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 to 2 cm2 the patient usually experiences symptoms.

  • Pathogenesis 
    • congenital
    • mitral annular calcification can obstruct the valve and can be misdiagnosed as mitral stenosis
    • myxomas or large obstructive clots in the left atrium can cause similar symptoms
    • rheumatic heart disease, but the incidence is low in the US
  • Clinical signs and symptoms
  • Cardiac auscultation 
    • opening snap (the most important sign)
    • noisy first heart sound (S1)
    • emphasized closure of the pulmonary valve (P2) in patients with pulmonary hypertension
    • diastolic murmur
  • Ultrasound findings 
    • 2D
      The following anomalies may be noted by the sonographer:
      • 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")
      • short axis view planimetry of the narrowed mitral valve area
      • left atrial dilation
      • presence of left atrial thrombus


        • Parasternal long axis
        mitral valve
        "elbowing"

    • M-mode
      The following anomalies may be noted by the sonographer:
      • small left ventricular end-diastolic internal dimension (LVIDd) and left ventricular end-systolic internal dimension (LVIDs)
      • normal or increased fractional shortening (FS)
      • reduced mitral D point (at end-systole) to E point (first peak of the anterior mitral valve leaflet) - (D-E) excursion
      • reduced mitral E point to F point (mid-diastolic trough of the anterior mitral valve leaflet) - (E-F) slope
      • increased left atrial dimension


        • Mitral valve small
        end diastolic/systolic
        dimension M-mode

    • Doppler
      When performing Doppler the sonographer would assess the turbulent high velocity dense jet and assesses for the presence of:
      • an increased E velocity, > 1.3 m/s at the mitral valve tips 
      • mitral regurgitation
      • tricuspid regurgitation
      • obstructed blood flow with high mean gradient
      • increased pressure half time


        Mitral valve
        stenosis with color

  • Quantification of mitral stenosis severity
    The sonographer performs the following assessments to determine the degree (mild, moderate, or severe) of the mitral stenosis:
    • peak velocity
    • peak and mean gradients
    • velocity time integral(VTI)
    • if mitral regurgitation and aortic regurgitation are absent the continuity equation is used to determine the mitral valve area (MVA):
      Note:
      Use the RVOT measurement in place of LVOT if significant aortic insufficiency is demonstrated.
    • if mitral regurgitation and aortic regurgitation are present the mitral valve area (cm2) is calculated using pressure half time (PHT): 
      MVA (cm2) = 220/PHT


      • Mitral stenosis
      spectral trace

    • planimetry using 2D (cm2) is a standard measurement to evaluate the narrowing of the mitral valve
      Severity of mitral
      stenosis      		 Peak velocity
      		 Mean pressure
      gradient

      		 Mitral valve area
      Mild stenosis < 3 m/s < 5 mmHg 1.5 cm2
      Moderate stenosis
      		 3-4 m/s 5-10 mmHg 1.0-1.5 cm2
      Severe stenosis > 4 m/s > 10 mmHg < 1.0 cm2
  • Additional imaging/tests
  • Prognosis
    • depends on the severity of the disease
  • Complications
1.2.2. Mitral regurgitation

Mitral regurgitation (or insufficiency) may be acute or chronic. The condition can occur with dysfunction in any component of the mitral valve (leaflets, chordae tendinae or papillary muscles). It results in the leaking of blood from the left ventricle to the left atrium through the mitral valve when the ventricle contracts during systole.


Mitral regurgitation


Mitral regurgitation
color Doppler

As blood leaks back into the left atrium, the blood volume and pressure in the left atrium increases. This can lead to atrial enlargement. The increased pressure may be transmitted backwards through the circulation into the pulmonary veins, leading to pulmonary edema. The left ventricle also enlarges as it chronically pumps harder, attempting to compensate for the blood being lost to the atrium.

Common causes of mitral regurgitation include: mitral valve prolapse, mitral annulus abnormalities, chordae and papillary muscle abnormalities and dysfunctions, and myocardial infarction. Rheumatic heart disease is also a known cause of mitral valve disease, but the incidence is low in the U.S.

Acute mitral regurgitation may arise due to damage to the chordae tendineae or papillary muscles, due to cardiac trauma, myocardial infarction, or endocarditis.

Chronic mitral regurgitation may arise due to mitral valve prolapse, or cardiac remodeling due to heart failure or coronary artery disease.

  • Pathogenesis
    • damage to the supporting structures of the valve by myocardial infarction, trauma, or endocarditis
    • cleft mitral valve
    • diet drug valvuopathy
    • mitral annular calcium
    • dilated cardiomyopathy
    • hypertrophic cardiomyopathy
    • myxoma
    • rheumatic heart disease
  • Clinical signs and symptoms
    • dyspnea
    • fatigue
    • palpitations
    • arrhythmias
    • systolic heart murmur
    • symptoms of heart failure
    • asymptomatic, if the condition is mild
  • Cardiac auscultation
  • Ultrasound findings
    • 2D
      The following anomalies may be noted by the sonographer:
      • enlargement of the left ventricle and/or left atrium
      • evidence of mitral valve pathology (eg, carditis due to rheumatic fever)
      • evidence of mitral valve dysfunction (eg, prolapse, ruptured chordae tendinae)


        • Parasternal long axis
        enlarged ventricle

    • M-mode
      The following anomalies may be noted by the sonographer: 
      • increased left ventricular end-diastolic internal dimension (LVIDd) and left ventricular end-systolic internal dimension (LVIDs)
      • normal or reduced fractional shortening (FS)
      • increased left atrial diameter (LAd) 
      • possible mitral valve prolapse


        • Left ventricle
        enlargement M-mode

    • Doppler
      When performing Doppler the sonographer locates the systolic retrograde blood flow across the mitral valve and determines the:
      • direction of the regurgitant jet
      • number of regurgitant jets
      • highest velocity of the turbulent flow
      • focal increased flow or velocity identified adjacent to the septal edge of the left ventricular outflow tract (known as systolic anterior motion [SAM])


        • Systolic anterior
        motion


        Apical four-chamber
        left mitral valve
        with color
  • Quantification of mitral regurgitation severity
    The sonographer performs the following assessments to determine the degree (mild, moderate, or severe) of the mitral regurgitation:
    • jet area width
    • jet density
    • descending aorta diastolic flow reversal
    • vena contracta width
    • pulmonary venous flow
    • regurgitant volume
    • regurgitant fraction
      Note:
      A severe mitral regurgitant jet is a wider (broader) waveform and is seen on the QRS complex; severe stenosis is a narrow waveform and seen after the QRS complex. Look for the opening and closing click of the aortic valve.
       
      Mitral regurgitation severity Mild Moderate Severe
      Jet area width in central jets % - color Doppler (using LA area) < 20% 20-40% > 40%
      Jet density faint or incomplete dense dense
      Descending aorta diastolic flow reversal brief intermediate prominent
      Vena contracta < 0.30cm 0.3-0.7 > 0.7
      Pulmonary venous flow dominance of systolic phase blunting of systole flow reversal in systole
      Regurgitant volume < 30 mL 30-44 mL >= 60 mL
      Regurgitant fraction < 30% 30-39% >= 50%
  • Additional imaging/tests
    • magnetic resonance angiography for quantification
    • physical examination
    • electrocardiography (ECG) may demonstrate:
      • acute myocardial infarction (acute mitral regurgitation)
      • left atrial enlargement (chronic mitral regurgitation)
      • left ventricular hypertrophy (chronic regurgitation)
    • chest x-ray may show left-sided hypertrophy
    • cardiac catheterization may be done pre-operatively, to evaluate the extent of valve disease
  • Treatment
    • Medication
      • to control arrhythmias
      • anticoagulants to prevent clot formation and emboli
      • to treat heart failure symptoms
    • Surgery
  • Prognosis
    • depends on left ventricular function
  • Complications
    • atrial fibrillation
    • emboli
    • infective endocarditis
    • heart failure
1.2.3. Mitral valve prolapse

Mitral valve prolapse describes a condition where the mitral leaflets degenerate (ie, myxtomatous degeneration) and fall back posteriorly into the left atrial cavity during ventricular systole.


Mitral valve prolapse


Ultrasound image of
mitral valve prolapse

Prolapse is caused by ruptured chordae tendineae, or thickened growths (the result of infection and fibrin deposits) on either or both the valve leaflets. Mitral valve prolapse intensifies mitral regurgitation and often occurs with connective tissue disease and other pathologies or conditions such as hyperthyroidism.

  • Pathogenesis
    • often unknown
    • connective tissue disease (eg, Marfan's syndrome) potentially causing an aorta aneurysm
    • coronary artery disease, rheumatic heart disease, cardiomyopathy
  • Clinical signs and symptoms
    • asymptomatic, if condition is mild
    • palpitations
    • dyspnea
    • fatigue
    • chest pain
    • systolic murmur with click
    • symptoms of heart failure
    • arrhythmia
  • Cardiac auscultation
    • mid to late systolic click
    • S1 may be prominent
    • late systolic murmur (high-pitched), if mitral regurgitation present
  • Ultrasound findings
    • 2D
           The following anomalies may be noted by the sonographer:
      • one or both of the mitral valve leaflets may prolapse (move backwards) beyond the mitral valve annulus into the left atrium during systole; the optimum view to demonstrate this is the parasternal long axis view.
      • enlargement of the left ventricle from significant mitral regurgitation
      • enlargement of the left atrium from significant mitral regurgitation
      • possible ruptured chordae tendineae
      • co-existing tricuspid, aortic and pulmonary valve prolapse


        • Parasternal long axis
        mitral valve
        prolapse 2D

    • M-mode
          The following anomalies may be noted by the sonographer:
      • during systole, the closed mitral valve leaflets move posteriorly instead of sloping upwards
      • increased LVIDd and LVIDs
      • normal or reduced fractional shortening (FS)
      • increased LAd
      • increased mitral EPSS


        • Parasternal long axis
        mitral valve
        prolapse increased
        LAd M-mode

    • Doppler
           When performing Doppler the sonographer locates the systolic retrograde blood flow across the mitral valve and determines the:
      • direction of the turbulent jet
      • number of regurgitant jets
      • highest velocity and measure VTI for regurgitant volumes/fractions
      • a focal increased flow or velocity identified adjacent to the septal edge of the left ventricular outflow tract; known as systolic anterior motion (SAM)


        • Mitral regurgitation
        color Doppler

  • Quantification of mitral regurgitation severity with mitral valve prolapse
    The sonographer performs a number of assessments to determine the degree (mild, moderate, or severe) of the mitral valve prolapse.
    Mitral regurgitation severity Mild Moderate Severe
    Jet area width in central jets % - color Doppler (using LA area) <20% 20-40% >40%
    Jet density faint or incomplete dense dense
    Descending aorta diastolic flow reversal brief intermediate prominent
    Vena contracta <0.30 cm 0.3-0.7 cm >0.7 cm
    Pulmonary venous flow dominance of systolic phase blunting of systole flow reversal in systole
    Regurgitant volume <30 ml 30-44 ml >=60 ml
    Regurgitant fraction <30% 30-39% >=50%
  • Additional imaging/tests
    • physical examination
    • electrocardiography (ECG) may demonstrate arrhythmia (eg, atrial fibrillation)
    • chest x-ray is often normal
    • cardiac catheterization may be done pre-operatively, to evaluate the extent of valve disease
  • Treatment
    • Medication
      • to control arrhythmias
      • anticoagulants to prevent clot formation and emboli
    • Surgery (rare)
    • Other
      • reassurance
      • avoid stimulants, (caffeine, alcohol)
      • screen relatives (often an inherited disorder)
  • Prognosis
    • usually a non-eventful disorder
  • Complications
    • atrial fibrillation
    • mitral regurgitation
    • pulmonary hypertension
    • heart failure
    • arrhythmia and sudden death
    • increased thromboembolic risk
    • endocarditis
1.2.4. Flail mitral valve

Flail mitral valve is similar to mitral valve prolapse. The valve has lost its supporting structures (ie, chordae tendineae or papillary muscle has ruptured, or leaflet tip has turned outwards), resulting in the valve left to flap in the blood stream. This always causes significant mitral regurgitation. It can be acute, caused by either chest trauma, or by acute ischemia from a myocardial infarct.


Flail mitral valve

  • Pathogenesis
    • infective endocarditis
    • chest trauma
    • acute ischemia
    • infarction
    • dilated cardiomyopathy resulting papillary muscle contraction
  • Clinical signs and symptoms
    • asymptomatic, if condition is mild
    • palpitations
    • dyspnea
    • fatigue
    • chest pain
    • symptoms of heart failure
    • arrhythmia
  • Cardiac auscultation
    • mid to late systolic click
    • S1 may be prominent
    • late systolic murmur (high-pitched), in presence of mitral regurgitation
  • Ultrasound findings
    • 2D
      The following anomalies may be noted by the sonographer:
      • thickening of the leaflet tips
      • shortening of one of the valve leaflets
      • anterior leaflet tip pointing in the opposite direction and visualized behind the normal posterior leaflet tip
      • posterior leaflet tip pointing in the opposite direction and seen behind the normally positioned anterior leaflet tip
      • a whipping movement may be visualized in the systolic phase
      • floating of the chordae tendineae


        • Apical four-chamber
        flail mitral
        valve 2D

    • M-mode
      The following anomalies may be noted by the sonographer:
      • systolic flutter
      • erratic posterior leaflet movement in the diastolic phase
      • erratic anterior leaflet movement in the diastolic phase
    • Doppler
      When performing Doppler the following may be demonstrated and assessed:
      • an eccentric, disorganized jet
      • a posterior flail tip presenting as a jet along the atrial wall
      • an anterior flail tip presenting as a jet in the opposite direction (a more lateral jet)
      • a central jet, if both the anterior and posterior flail tips affected
      • mitral regurgitation
      • highest velocity for regurgitant volume/fraction
Note:
Color flow Doppler may underestimate the severity of the mitral regurgitation; these are jets that hug the wall or the native valve, and are referred to as the "coanda effect".
 


Apical two-chamber
flail mitral valve
eccentric jet

  • Quantification of mitral regurgitant severity in flail mitral valve
    The sonographer performs a number of assessments to determine the degree (mild, moderate, or severe) of the flail mitral valve.
    Mitral regurgitation severity Mild Moderate Severe
    Jet density faint or incomplete dense dense
    Descending aorta diastolic flow reversal brief intermediate prominent
    Vena contracta width <0.30 cm 0.3-0.7 cm >0.7 cm
    Pulmonary venous flow dominance of systolic phase blunting of systole flow reversal in systole
    Regurgitant volume <30 ml 30-44 ml >=60 ml
    Regurgitant fraction <30 % 30-39 % >=50 %
NOTE:
It may be difficult to quantify an eccentric regurgitant jet due to its abnormal direction and limited viewpoints.
 
  • Additional imaging/tests
    • electrocardiography (ECG)
    • chest x-ray
    • echocardiography
    • cardiac catheterization
  • Treatment
    • Medication
      • to control arrhythmias
      • anticoagulants to prevent clot formation and emboli
    • Surgery (rare)
      • valve repair
      • valve replacement
    • Other
      • reassurance
      • avoid stimulants, (caffeine, alcohol)
      • screen relatives (often an inherited disorder)
  • Prognosis
    • usually a non-eventful disorder
  • Complications
    • atrial fibrillation
    • mitral regurgitation
    • pulmonary hypertension
    • heart failure
    • arrhythmia and sudden death
    • increased thromboembolic risk
    • endocarditis
1.2.5. Mitral annulus calcification

Mitral annular calcification is a chronic degenerative process that results in calcium deposits in the mitral annulus, sometimes extending into the base of the leaflets. Calcification usually starts around the margins of the posterior leaflet (forming a semi-circular band similar to a C, U, or reverse C) and then progresses to anterior leaflet involvement (to form an O). The mitral valve annulus becomes thick, rigid and calcified, and can interfere with valve closure. Blood flow is not usually compromised. Mitral annular calcification is often seen in elderly patients and in patients with renal disease.

  • Pathogenesis
    • ageing
    • chronic renal failure, especially with patients on dialysis
    • hypertension
    • myxtomatous degeneration
    • a result of connective tissue disease, metabolic disorders, or mitral stress, in young patients
    • gender (higher female incidence)
    • hypercholesterolemia
    • diabetes mellitus
    • associated with coronary artery disease
  • Clinical signs and symptoms
    • hypertension
    • aortic stenosis
    • mitral valve prolapse
    • arterial embolization
  • Cardiac auscultation
    • there may be no abnormal sounds
    • S1 may be prominent
    • high-pitched late systolic murmur if mitral regurgitation is present
  • Ultrasound findings
    • 2D
      The following anomalies may be noted by the sonographer:
      • degenerative annular calcification of either one or both of the valve leaflets
      • thickened valve leaflets
      • restricted movement and narrowed orifice
      • fusion of the anterior and posterior leaflets causing a reduced opening of the mitral valve leaflets
      • possible evidence of commissural fusion
      • left atrial dilation with increasing disease due to narrowing of the orifice
      • left atrium dilation
      • presence of left atrial thrombus
      • presence/absence of other cardiac mass-effect of the leaflets


        • Parasternal long axis
        thickening/calcification
        of mitral valve
        leaflets 2D

    • M-mode
      The following anomalies may be noted by the sonographer:
      • increased LVIDd and LVIDs with narrowing of orifice
      • normal or reduced fractional shortening (FS)
      • increased LAd


        • Left ventricle
        dimension M-mode

    • Doppler
      During Doppler the following may be demonstrated and assessed:
      • normal flow
      • turbulent jet
      • co-existence of mitral regurgitation
      • tricuspid regurgitation
      • an obstruction/stenosis, with an increased velocity flow
  • Quantification of mitral annulus calcification, mitral regurgitation, and/or mitral stenosis severity
    The sonographer performs a number of assessments to determine the degree (mild, moderate, or severe) of valvular disease (mitral regurgitation, mitral stenosis).
    • peak velocity
    • peak and mean pressure gradients
    • VTI
    • measurement of the mitral valve thickness in the apical 4-chamber view
      Mitral Annular Calcification Measurement of the valve thickness
      Mild 1.5-5 mm
      Moderate 6-10 mm
      Severe > 10 mm
  • Additional imaging/tests
    • Computed tomography (CT)
    • physical examination
    • chest x-ray
    • cardiac catheterization
  • Treatment
    • Medication
      • antibiotic prophylaxis prior to procedures (eg, endoscopy, hospitalization, catheterization) that increases risk of infective endocarditis
    • Surgery (rare)
  • Prognosis
    • considered a benign cardiac abnormality
    • not clinically important unless vast amounts of calcification
  • Complications
    • bacterial endocarditis
    • infection (eg, abscess), increased thromboembolic risk
    • mitral valve regurgitation in severe cases of calcification

 

1.2.6. Proximal isovelocity surface area

The PISA method is used to calculate the "effective regurgitant orifice area" (EROA). This is based on the continuity principle of flow: "what goes in must come out".

Flow through a normal region (Q₁), must equal the flow through the narrowest region (Q₂)
Q₁=  Q₂

If the orifice has narrowed, there is an increase in velocity and decrease in pressure across the narrowing to maintain the flow. This is known as Bernoulli's principle. Therefore, flow through the region before the narrowed orifice must equal flow through the actual orifice.


Continuity flow

Therefore, if:
Flow = Area x Velocity
Then:
inflow = outflow
Hence:
Area PISA x Velocity PISA = Area EROA x Velocity EROA


The flow proximal to the regurgitant orifice is calculated from the:

  • area of the convergence; calculated from the hemispherical radius of the PISA dome 
    Area = 2 p r 2
  • velocity at the surface of the PISA dome; calculated by the Nyquist velocity limit (the point where the color aliases from blue to red)
    V n
  • velocity of the regurgitant jet; obtained by using continuous wave Doppler and measuring the peak velocity 
    V max

The EROA is therefore calculated as:

The sonographer calculates the PISA for mitral stenosis or mitral regurgitation thus:

  • The LVOT diameter is measured to assess the cross-sectional area (CSA).
  • A 2D image of the affected valve is then obtained.
  • The regurgitant/stenotic orifice is optimized using color Doppler.
  • Zooming of the selected valve is performed to identify the color contrasts clearly.
  • The color Doppler baseline is shifted down to an aliasing velocity (usually 20-30 m/s) for a regurgitant jet, or shifted up to aliasing velocity (usually 20-30 m/s) for a stenotic jet.
  • The image is then frozen and the best radial hemisphere is selected (usually seen in the midsystolic phase). 
  • The PISA dome radius is measured and saved.
  • The peak velocity and velocity time integral (VTI) of the regurgitant/stenotic jet is then measured using CW Doppler.


Radius/PISA:
narrowed orifice

1.2.7. Mitral valve replacement

Echocardiography is the method of choice to assess and evaluate the function of prosthetic valve replacements.

It is important to obtain a full patient valve replacement history prior to commencing the scanning protocol.

The objective for 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
  • presence of valvular/peri-valvular abscess
  • chamber size and ventricular function (this helps to give an overall review on how well the prosthetic valve is working)

Imaging the prosthetic valve is challenging; this is due to the acoustic properties of these grafts. The material the grafts are made from can result in artifacts, acoustic shadowing, and increased echogenicity. These effects reduce the resolution obtained during the echocardiography exam.

  • Ultrasound findings of bioprosthetic and mechanical mitral valve replacements
    • 2D
      The following anomalies may be noted by the sonographer:
      • 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 artifact is moving, the occluder is moving - use the artifact to advantage
      • presence of thrombus and vegetations
      • dehiscence (bursting open of the suture line) or abscess of the valve ring; visualized by the excessive rocking motion at the point of the sewing ring
      • pseudoaneurysm of the valve bed
      • a sudden increase in the left atrial size indicates a change in the prosthetic valve status
    • M-mode
      The following anomalies may be noted by the sonographer:
      • normal or small left ventricular end-diastolic internal dimension (LVIDd), and left ventricular end-systolic internal dimension (LVIDs)
      • increased wall thickness
      • normal or increased fractional shortening (FS)
    • Doppler
      When performing Doppler the sonographer would assess the following:
      • maximum velocity - it is recommended that multiple windows are used when performing this assessment
      • flow direction specific for disc type, using color Doppler
      • diastolic flow reversal in thoracic aorta in severe cases
      • regurgitation (valvular or peri-valvular) - this is difficult due to the artifacts displayed in the left atrium
      • peri-valvular leaks
      • high velocity jet obtained with CW through the dehiscence site
  • Quantification of dysfunction of prosthetic valve severity
    The sonographer performs a number of assessments to determine the degree (mild, moderate, or severe) of valvular function.
    • peak velocity
    • mean pressure gradients
    • VTI
    • aortic valve area (AVA) using the continuity equation
      Severity of mitral valve function Peak velocity Mean pressure Gradient Valve area (EOA) VTI prmv/ VTILVOT Pressure half time
      Normal < 1.9 m/s <= 5 mmHg >= 2 cm2 < 2.2 < 130 ms
      Possible stenosis 1.9-2.5 m/s 6-10 mmHg 1-2 cm2 2.2-2.5 130-200 ms
      Severe stenosis >= 2.5 m/s > 10 mmHg < 1 cm2 > 2.5 > 200 ms
       
      Prosthetic mitral valve regurgitation Mild Moderate Severe
      Structure of valve normal abnormal abnormal
      Left ventricle size normal normal or dilated usually dilated
      Color jet width in central jets % - color Doppler (using LA area) < 20% 20%-39% > 40%
      Jet density faint or incomplete complete dense
      Pulmonary venous flow dominance of systolic phase blunting of systole flow reversal in systole
      Regurgitant fraction < 30% 30-49 % >= 50 %
      Regurgitant volume (per beat) < 30 ml 30-59 ml >= 60 ml

    • Note:
    The above values are generic prosthetic valve replacement values. For more specific values relating to the valve type (eg, Starr-Edwards) refer to http://www.asecho.org/files/public/PVText.pdf
 

Step 2: Aortic valve

2.1. Basic physiology

During left ventricle contraction (systole), pressure in the left ventricle increases until it exceeds the pressure within the aorta. This pressure gradient change results in the opening of the aortic valve and blood flows from the left ventricle into the aorta.

During diastole (relaxation of the left ventricle) the pressure within the ventricle quickly decreases. The pressure within the aorta then becomes greater than that in the left ventricle, causing the aortic valve to close.


Aortic valve

2.2. Pathology

2.2.1. 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.


Aortic stenosis

  • Pathogenesis
    • age-related calcification of the leaflets
    • syphilis
    • congenital
  • 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 (eg, heavy exercise)
    • rheumatic heart disease
    • asymptomatic, if the condition is mild
  • Cardiac auscultation
    • a systolic thrill may radiate to the base of the heart and along the carotid arteries
    • a harsh systolic crescendo-decrescendo ejection murmur that is associated with the bicuspid valves may be heard
    • there may be a prominent S4, which indicates the presence of left ventricular hypertrophy
    • a tardus parvus pulse may be noted
    • high-pitched, diastolic blowing murmur may be heard, which can indicate the presence of associated aortic regurgitation
  • Ultrasound findings
    • 2D
      The following anomalies may be noted by the sonographer:
      • leaflet thickening with restricted motion
      • leaflet retraction
      • calcification
      • abnormal aortic valve anatomy - (eg, a unicuspid, bicuspid, or asymmetric tricuspid visualized in the parasternal short axis in the systole phase. A quadracuspid valve, however, would be best seen in the diastole phase.
      • left ventricular hypertrophy
      • enlarged left ventricle size and decreased systolic function
      • possible enlargement of the aortic root

        Apical five-chamber
        aortic valve
        thickening 2D
    • M-mode
      The following anomalies may be noted by the sonographer:
      • normal or small left ventricular end-diastolic internal dimension (LVIDd) and left ventricular end-systolic internal dimension (LVIDs)
      • increased wall thickness
      • normal or increased fractional shortening (FS)
      • normal or reduced mitral E point to septal separation (EPSS)

        Increased left
        ventricular wall
        thickness
        M-mode
    • Doppler
      When performing Doppler the sonographer would determine the presence of and assess the:
      • 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 - subvalular, valvular, or supravalvular (coarctation)
      • co-existence of aortic insufficiency
      • left ventricle diastolic dysfunction/filling abnormalities
      • concurrent mitral regurgitation (common in the older population)

        Aortic stenosis
        Doppler
  • Quantification of aortic stenosis severity
    The sonographer performs a number of assessments to determine the degree (mild, moderate, or severe) of aortic stenosis.
    • peak velocity
    • peak and mean pressure gradients
    • VTI
    • aortic valve area (AVA) using the continuity equation
    • aortic valve index
    • dimensionless velocity ratio (VR)
      Note:
      A severe mitral regurgitant jet is a wider (broader) waveform and is seen on the QRS complex; severe aortic stenosis is a narrow waveform and seen after the QRS complex. Look for the opening and closing click of the aortic valve.
Severity of aortic stenosis Peak velocity Peak pressure gradient Mean pressure gradient Valve area Aortic valve index Velocity
ratio
Mild stenosis < 3 m/s < 36 mmHg < 20 mmHg 1.5 cm2 > 0.8 cm2/m2 > 0.50
Moderate stenosis 3-4 m/s 36-50 mmHg 20-40 mmHg 1.0-1.5 cm2 0.60 - 0.85 cm2/m2 0.25-0.50
Moderately severe stenosis - 50-64 mmHg - - - -
Severe stenosis > 4 m/s > 64 mmHg > 40 mmHg < 1.0 cm2 < 0.6 cm2/m2 < 0.25
 
  • Additional imaging/tests
    • radionuclide studies for myocardial perfusion evaluation
    • physical examination
    • electrocardiography (ECG)
    • chest x-ray
    • cardiac catheterization
  • Prognosis
    • average survival is less than five years
    • incidence of sudden death is 15 to 20%
    • once in left ventricular failure, survival is possibly a little over a year
2.2.2. Aortic regurgitation

Aortic regurgitation (or insufficiency) occurs when blood leaks from the aorta into the left ventricle when the ventricle relaxes during diastole.


Aortic regurgitation

In diastole the left ventricle relaxes, allowing blood to flow in naturally from the left atrium. However, if at the same time blood leaks back from the aorta, the volume and pressure in the left ventricle increases. Over time, the ventricle muscle wall hypertrophies and the overloaded chamber compensates for the extra volume by dilating. Systolic function usually remains within the normal range.

Aortic regurgitation may be congenital (a bicuspid aortic valve), or result from another condition, such as aortic root dilation or dissection. Rheumatic heart disease is also a known cause of aortic regurgitation.

  • Pathogenesis
    • aortic dissection or aneurysms
    • congenital
    • infective endocarditis
    • rheumatic heart disease
  • Clinical signs and symptoms
    • asymptomatic, if the condition is mild
    • chest pain
    • exertional dyspnea
    • symptoms of heart failure, earlier in the disease
    • diastolic murmur
  • Cardiac auscultation
    • high-pitched, blowing, diastolic decrescendo murmur
    • Austin Flint murmur, - known to be associated with severe aortic regurgitation
    • systolic ejection murmur
    • S3
    • S4 - suggests left ventricular hypertrophy in chronic cases; absent in acute cases
  • Ultrasound findings
    • 2D
      The following anomalies may be noted by the sonographer:
      • enlargement of the left ventricle
      • possible enlargement of the aortic root
      • abnormal aortic valve pathology (eg, sclerotic, rheumatic)
      • abnormal aortic valve function (eg, prolapse [backward motion of the valve], coaptation failure [when the leaflets do not join together when the valve is closed])
        Apical four-chamber
        large left ventricle
    • M-mode
      The following anomalies may be noted by the sonographer:
      • increased LVIDd and LVIDs
      • normal or reduced fractional shortening (FS)
      • normal or increased mitral EPSS

        Aortic regurgitation
        left ventricle
        enlargement
        M-mode
    • Doppler
      When performing Doppler the sonographer would determine the presence of and assess the:
      • retrograde flow from the aortic root to the left ventricle during diastole
      • focal increase in color flow or turbulent jet
      • direction of the turbulent jet
      • number of regurgitant jets
      • highest velocity of the turbulent flow
      • brief diastolic flow reversal; seen in the aortic arch with mild regurgitation
      • holodiastolic flow reversal in the aortic arch; seen in severe regurgitation

        Aortic regurgitation
        color Doppler
        Aortic regurgitation
        spectral Doppler

Severity of aortic insufficiency Pressure half time Regurgitant jet density Vena contracta width Jet width/LVOT Ratio
Mild > 500 ms faint or incomplete < 3 mm < 25%
Moderate 200-500 ms dense 3-5 mm 25-46%
Moderately Severe       47-64%
Severe < 200 ms very dense > 6 mm >= 65%
 
Severity of aortic insufficiency Regurgitant volume EROA Regurgitant fraction
Mild < 30 mls < 10 mm2 < 30%
Moderate 30-44 mls 10-19 mm2 30-49%
Moderately Severe 45-50 mls 19-29 mm2  
Severe >= 60 mls > 30 mm2 >= 50%
 

  • Additional imaging/tests
    • physical examination
    • electrocardiography (ECG)
    • chest x-ray
    • cardiac catheterization
  • Prognosis
    • depends on the severity of the disease
2.2.3. Bicuspid aortic valve

Bicuspid aortic valve (also known as bicommissural aortic valve) is a common congenital inheritable condition where the aortic valve has two leaflets instead of the normal three (two cusps have become conjoined). Bicuspid aortic valve usually results in leakage of blood back into the ventricle (aortic regurgitation), aortic stenosis, and an enlarged aorta.


Bicuspid valve


Ultrasound image of
bicuspid aortic valve

  • Clinical presentation
    • asymptomatic
    • congestive heart failure in babies
    • chest pain
    • breathing difficulties
    • heart palpitations
    • pallor
    • cyanosis
  • Cardiac auscultation
    • systolic ejection click
    • split S2 with normal inspiration
    • systolic crescendo-decrescendo ejection murmur; stronger with increasing stenosis
  • Ultrasound findings
    • 2D
      The following anomalies may be noted by the sonographer:
      • thickening/calcification and restricted motion of the leaflets
      • retraction of the leaflets
      • abnormal aortic valve anatomy - (eg, unicuspid, bicuspid, or asymmetric tricuspid visualized in the parasternal short axis in the systole phase. A quadracuspid valve, however, is seen in the diastole phase.
      • eccentric closure point (not in the middle) of the aortic valve in the parasternal long axis view
      • aortic valve opening appears round (also known as "football-shaped") which is visualized in the parasternal short axis
      • "doming" of the leaflets in systole
      • left ventricular hypertrophy
      • enlarged left ventricle size and decreased systolic function
      • possible enlargement of the aortic root
    • M-mode
      The following anomalies may be noted by the sonographer:
      • normal opening of the aortic valve, but eccentric closure line (ie, not in the middle)
      • thickening of the valve leaflets
      • normal LVIDd and LVIDs
      • normal fractional shortening (FS)

        Bicuspid aortic
        valve leaflets
        M-mode
    • Doppler
      When performing Doppler the sonographer determines the presence of and assesses the:
      • valvular obstruction to blood flow with high mean gradient
      • diastolic filling abnormalities of the left ventricle
      • turbulent high velocity dense eccentric jet
  • Quantification of aortic stenosis severity due to a bicuspid valve
    The sonographer performs a number of assessments to determine the degree (mild, moderate, or severe) of aortic stenosis:
Severity of aortic stenosis Peak velocity Peak pressure gradient Mean pressure gradient Valve area Aortic valve index Velocity ratio
Mild stenosis < 3 m/s < 36 mmHg < 20 mmHg 1.5 cm2 > 0.8 cm2/m2 > 0.50
Moderate stenosis 3-4 m/s 36-50 mmHg 20-40 mmHg 1.0-1.5 cm2 0.60 - 0.85 cm2/m2 0.25-0.50
Moderately severe stenosis - 50-64 mmHg - - - -
Severe stenosis > 4 m/s > 64 mmHg > 40 mmHg < 1.0 cm2 < 0.6 cm2/m2 < 0.25
 
  • Additional imaging/tests
    • physical examination
    • electrocardiography (ECG)
    • chest x-ray
    • cardiac catheterization
    • angiography
    • MRI
    • transesophageal echocardiography
    • familial testing
  • Prognosis
    • depends on severity of the disease
    • depends on whether there are additional physical defects noted at birth
    • if asymptomatic at birth complications may become apparent during adulthood, or may never present
  • Complications
    • congestive heart failure
    • aortic regurgitation
    • aortic stenosis
    • infective endocarditis
    • aortic aneurysm
2.2.4. Aortic valve prolapse

Aortic valve prolapse is the downward displacement of one or more aortic valve leaflets below a line joining the points of attachment of these leaflets. Blood flows backwards from the aorta into the left ventricle.

Aortic valve prolapse is a frequent cause of aortic regurgitation and is associated with bicuspid aortic valve.


Aortic valve
prolapse

  • Pathogenesis
    • infective endocarditis
    • severe mitral regurgitation
    • aortic root dilation
    • congenital
    • high blood pressure
    • rheumatic fever
  • Clinical presentation
    • heart palpitations
    • reduced exercise capacity
    • shortness of breath
    • strong, racing pulse
  • Cardiac auscultation
    • no abnormal sounds in early stages
    • high-pitched, blowing, diastolic decrescendo murmur relating to aortic insufficiency
    • Austin Flint murmur, which has a known association with severe aortic regurgitation
    • systolic ejection murmur relating to aortic insufficiency
    • S3 relating to aortic insufficiency
  • Ultrasound findings
    • 2D
      The following anomalies may be noted by the sonographer:
      • thickening of the valve leaflets
      • one or more of the valve leaflets are displaced beyond the point of attachment
      • coaptation failure (when the leaflets do not join together when the valve is closed)
      • enlargement of the left ventricle
      • possible enlargement of the aortic root
      • abnormal aortic valve pathology (eg, sclerotic, rheumatic)

        Parasternal long
        axis aortic valve
        prolapse
    • M-mode
      The following anomalies may be noted by the sonographer:
      • thickening of the valve leaflets
      • increased LVIDd and LVIDs
      • normal or reduced fractional shortening (FS)

        Increased left
        ventricle dimension
        M-mode
    • Doppler
      When performing Doppler the sonographer would determine the presence of and assess the:
      • retrograde flow from the aortic root to the left ventricle during diastole
      • focal increase in color flow or turbulent jet
      • direction of the turbulent jet
      • number of regurgitant jets
      • brief diastolic flow reversal (seen in the aortic arch with mild regurgitation)
      • holodiastolic flow reversal (seen in aortic arch with severe regurgitation)

        Apical five-chamber
        aortic regurgitation
        color Doppler

Severity aortic insufficiency Pressure half time Regurgitant jet density Vena contracta width
Mild > 500 ms faint or incomplete < 3 mm
Moderate 200-500 ms dense 3-5 mm
Moderately severe      
Severe < 200 ms very dense > 6 mm

 
Severity aortic insufficiency  Jet width/LVOT ratio Regurgitant volume EROA Regurgitant fraction
Mild <25% <30 mls <10mm2 <30%
Moderate 25-46% 30-44 mls 10-19 mm2 30-49%
Moderately severe 47-64% 45-50 mls 19-29 mm2  
 Severe >= 65% >= 60 mls >30mm2 >= 50%
 
  • Additional imaging/tests
    • physical examination
    • electrocardiography (ECG)
    • chest x-ray
    • cardiac catheterization (left heart)
    • transesophageal echocardiogram (TEE)
    • angiography
  • Prognosis
    • depends on the severity of the disease
  • Complications
    • pulmonary edema
    • heart failure (left-sided)
    • endocarditis
2.2.5. Idiopathic hypertrophic subaortic stenosis (IHSS)

Idiopathic hypertrophic subaortic stenosis (now known as hypertrophic cardiomyopathy) describes various conditions where the main abnormality is abnormal thickening of the myocardium. Hypertrophic cardiomyopathy may occur in various regions of the heart, for example the apex or the interventricular septum. The most common form results in hypertrophy of the interventricular septum, whilst other segments of the ventricular walls remain normal or are only mildly increased.

When hypertrophic cardiomyopathy results in obstruction to blood flow, it becomes known as obstructive hypertrophic cardiomyopathy. The obstruction may occur at any location where the hypertrophy is located, but the most common location is the left ventricular outflow tract, resulting from hypertrophy of the interventricular septum. Signs of outflow tract obstruction include systolic anterior motion (SAM) of the anterior mitral valve leaflet, and early closure of the aortic valve.


Parasternal long axis
hypertrophic cardiomyopathy


Parasternal short axis
hypertrophic cardiomyopathy


Idiopathic hypertrophic
subaortic stenosis
  • Pathogenesis
    • Hypertrophic cardiomyopathy may be inherited as an autosomal-dominant trait and be present at birth.
    • It may be acquired later in life in cases where tumors cause acromegaly or pheochromocytoma.
  •  Clinical presentation
    • dyspnea
    • fatigue
    • chest pain
    • palpitations
    • dizziness
    • sudden cardiac death
    • heart murmur may be present
    • syncope
    • arrhythmias
  • Cardiac auscultation
    • S2 is reversely split
    • S3 in cases of congestive heart failure
    • S4 is commonly heard
    • second carotid arterial pulse is commonly heard in the late systole
    • ejection systolic murmur
    • holosystolic murmur heard with systolic anterior motion (SAM) of the mitral valve
  • Ultrasound findings
    • 2D
      The following anomalies may be noted by the sonographer:
      • thickening and lengthening of either of the mitral valve leaflets
      • increased wall thickness
      • presence of mitral aortic calcification (MAC)
      • normal or reduced left ventricular size
      • normal left ventricular systolic function
      • possible dilated left atrium
      • presence of left ventricular hypertrophy
      • speckling appearance of the interventricular septum


      • Apical four-chamber
      hypertrophic cardiomyopathy

    • M-mode
      The following anomalies may be noted by the sonographer:
      • possible increased wall thickness (depending on location of hypertrophy)
      • normal or reduced LVIDd and LVIDs
      • normal fractional shortening (FS)
      • "venturi effect", creating systolic anterior motion (SAM) of the mitral valve, indicated by a point in time where the anterior mitral valve leaflet touches the interventricular septum
      • early closing of the aortic valve
      • dilated left atrium with increasing left ventricle filling pressures

        Left ventricle hypertrophic
        cardiomyopathy M-mode
        Mitral valve
        leaflets touching
        septum M-mode
    • Doppler
      When performing Doppler the sonographer would determine the presence of and assess the:
      • site of the obstruction - subaortic (SAM) or midventricular (papillary level) - by using pulsed wave Doppler, moving the sample volume from the apex to the LVOT
      • turbulent color Doppler flow at the LVOT site
      • increase in LVOT velocity with the Valsalva method
      • turbulent jet at the papillary muscle site - midventricular obstruction
      • severity of mitral regurgitation
      • mitral regurgitation caused by SAM; this is seen as a change in shape of the CW Doppler waveform, which has the appearance of a dagger (triangle) shape
      • dagger appearance of the waveform is also seen in the midventricular obstruction, without the presence of SAM
      • grade of diastolic filling abnormalities

        Apical five-chamber
        left ventricular
        outflow tract - SAM
  • Quantification of IHSS
    The sonographer performs a number of assessments to determine the degree (mild, moderate, or severe) of IHSS.
    • there is a reduction in the TDI mitral annulus E'
    • an increase in the TDI mitral annulus ratio E/E' >= 10 may be noted
    • LA volume increases; >= 35 mmHg
    • peak pressure gradient across the LVOT obstruction is significant > 50 mmHg
    • there is an increase in the mean pressure gradient across the obstruction site
    • grade of diastolic dysfunction (abnormal relaxation/pseudo-normal or restrictive filling)
    • SAM - moderate disease involves the brief contact with the septum
    • SAM - severe disease involves the prolonged contact with the septum
    • presence, direction and severity of mitral regurgitation
  • Additional imaging/tests
    • physical examination
    • electrocardiography (ECG)
    • chest x-ray
    • cardiac catheterization
    • radionuclide imaging
    • Holter monitoring and event ECG
    • electrophysiology studies
  • Treatment
    • Specific treatment should be targeted at specific causes (eg, removal of tumors by surgery).
    • Medication
      • Beta blockers and calcium channel blockers slow the heart rate and reduce the force of contraction of the heart to give more filling time.
    • Surgery
      • Removal of the excess heart muscle may relieve symptoms when medication fails.
  • Prognosis
    • Four percent of cases die each year.
    • Death is usually secondary to an arrhythmia.
    • Death may be due to chronic heart failure, but this is less common.
    • People with genetic disorders may choose to undergo genetic counseling before planning a family.
    • People may also undertake regular prophylactic scanning in families with a history of hypertrophic cardiomyopathy.
  • Complications
    • arrhythmias
    • sudden death
    • heart failure
    • infective endocarditis
2.2.6. Aortic valve replacement

Echocardiography is the method of choice to assess and evaluate the function of prosthetic valve replacements.

It is important to obtain a full patient valve replacement history prior to commencing the scanning protocol.

The objective for 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
  • presence of valvular/peri-valvular abscess
  • chamber size and ventricular function (this helps to give an overall review on how well the prosthetic valve is working)

Imaging the prosthetic valve is challenging; this is due to the acoustic properties of these grafts. The material the grafts are made from can result in artifacts, acoustic shadowing, and increased echogenicity. These effects reduce the resolution obtained during the echocardiography exam.

  • Ultrasound findings of a biological, bioprosthetic, and mechanical aortic valve
    • 2D
      The following anomalies may be noted by the sonographer:
      • increased thickened/calcified leaflets
      • restricted leaflet motion
      • presence of thrombus and vegetations
      • dehiscence; visualized by the excessive rocking at point of the sewing ring
    • M-mode
      The following anomalies may be noted by the sonographer:
      • normal or small left ventricular end-diastolic internal dimension (LVIDd) and left ventricular end-systolic internal dimension (LVIDs)
      • increased wall thickness
      • normal or increased fractional shortening (FS)
      • normal or reduced mitral E point to septal separation (EPSS)
    • Doppler
      When performing Doppler the sonographer would assess the following:
      • maximum velocity (it is recommended that multiple windows are used when performing this assessment)
      • flow direction specific for disc type, using color Doppler
      • diastolic flow reversal in thoracic aorta in severe cases
      • regurgitation (valvular or peri-valvular); this is difficult due to the artifacts displayed in the left atrium
      • peri-valvular leaks
      • high velocity jet obtained with CW through the dehiscence site
  • Quantification of dysfunction of aortic prosthetic valve severity
    The sonographer performs a number of assessments to determine the degree (mild, moderate, or severe) of aortic prosthetic valve dysfunction.

Step 3: Tricuspid valve

3.1. Basic physiology

The tricuspid valve is the right atrioventricular valve. When blood enters the right atrium from the vena cavae, it must pass through the tricuspid valve before entering the right ventricle. The tricuspid valve has three leaflets and three papillary muscles that are connected by chordae tendinae to the right ventricle.

When the right ventricle relaxes (diastole) the tricuspid valve opens, allowing deoxygenated blood in the right atrium to flow into the right ventricle. Initially the flow is rapid (E wave on Doppler echocardiography), then the flow begins to slow. The right atrium contracts (end-diastole) forcing more blood into the right ventricle (A wave); this is also known as atrial kick. The ventricle then contracts (systole), triggering the closure of the tricuspid valve, preventing a back-flow of blood into the right atrium. Blood in the right ventricle then travels through the pulmonary valve into the pulmonary artery, flowing to the lungs.

Pathology of the tricuspid valve is more commonly seen in intravenous drug users.


Tricuspid valve

3.2. Pathology

3.2.1. Tricuspid stenosis

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

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

  • Pathogenesis
    • carcinoid heart disease
    • infective endocarditis
    • congenital stenosis
    • rheumatic heart disease
  • Clinical signs and symptoms
    • asymptomatic, if mild
    • fatigue
    • right upper chest pain or palpitations
    • symptoms of heart failure
    • palpitations
    • arrhythmias
  • Cardiac auscultation
  • Ultrasound findings
    • 2D
      The following anomalies may be noted by the sonographer:
      • thickening tricuspid valve leaflets with restricted motion (especially at tips and chordae tendinae)
      • diastolic "doming" of the valve visualized in the apical four-chamber and parasternal long axis views, from commissural fusion of leaflets
      • dilation of the right atrium
      • dilated inferior vena cava and hepatic veins
      • leftward bowing of the interatrial septum towards the left atrium
      • rheumatic tricuspid stenosis - this almost always co-exists with mitral stenosis
    • M-mode
      The following anomalies may be noted by the sonographer:
      • thickened tricuspid valve leaflets
      • decreased E-F slope of the anterior tricuspid valve leaflet
      • anterior motion of the posterior tricuspid valve leaflet
    • Doppler
      When performing Doppler the sonographer would check the presence of and assess:
      • turbulent flow
      • tricuspid inflow jet demonstrated on color Doppler; this is characterized as candle flame-shaped with a mosaic centre (like mitral stenosis)
      • increased E velocity > 1.0 m/s at the leaflet tips
      • increased pressure half time (decreased E-F slope)
      • increased giant 'A' wave of the hepatic vein by PW doppler
      • flow convergence proximal to leaflets demonstrated on color Doppler
  • Quantification of the tricuspid stenosis severity
    The sonographer performs a number of assessments to determine the degree (mild, moderate, or severe) of tricuspid stenosis.
    • mean and peak pressure gradients
    • tricuspid valve area is measured using the:
      • PISA method (limited use)
      • continuity equation (same as mitral stenosis), or
      • pressure half time (not reliable with co-existing tricuspid regurgitation)
        Severity of tricuspid stenosis Mean pressure gradient Tricuspid valve area
        Normal   7-9 cm2
        Mild < 2 mmHg  
        Moderate 2-5 mmHg  
        Severe > 5 mmHg < 1 cm2
  • Additional imaging/tests
    • physical examination
    • electrocardiography (ECG)
    • chest x-ray
    • cardiac catheterization
    • stress echo or TEE
  • Prognosis
    • dependent directly on primary disease
  • Complications
    • prosthetic valve infection
    • tricuspid regurgitation
    • thromboembolization
3.2.2. Tricuspid regurgitation

Tricuspid regurgitation (also known as tricuspid insufficiency or incompetence) is a common disorder that results in the back-flow of blood from the right ventricle into the right atrium during systole; it may be acute, chronic, or intermittent.

Tricuspid regurgitation is usually the result of functional disorders (eg, pulmonary hypertension), that obstruct normal blood flow through the pulmonary circulation. The right ventricle enlarges to compensate for this obstruction, resulting in the valve stretching, and causing leakage of blood backwards into the right atrium. Tricuspid regurgitation can also result from damage to the heart apparatus (eg, the valves, as a result of infection from intravenous [IV] drug use or trauma to the ventricle).

Regardless of whether tricuspid regurgitation is a result of a functional or anatomic disorder, the right atrium enlarges due to the collection of blood, and atrial pressure increases. The increase in pressure, and atrial size, results in arrhythmias and ultimately right-sided heart failure with liver congestion.

  • Pathogenesis
    • Primary (anatomic)
      • carcinoid heart disease
      • infective endocarditis due to IV drug use
      • congenital birth defects (eg, Ebstein's anomaly)
      • trauma
      • pacemakers, wires
      • tricuspid valve prolapse
      • heart transplant
      • rheumatic heart disease
    • Secondary (functional)
      • emphysema
      • pulmonary hypertension
      • pulmonic stenosis
      • abnormalities of the left heart
      • right ventricle infarction
      • constrictive pericarditis
  • Clinical signs and symptoms
    • dyspnea on exertion
    • weakness
    • tiredness
    • pulsations in the neck
    • enlarged liver
    • edema (predominately the legs)
  • Cardiac auscultation
    • holosystolic murmur
    • diastolic low rumble
    • Rivero-Carvallo's sign (tricuspid regurgitant murmur more easily heard with inspiration)
  • Ultrasound findings
    • 2D
      The following anomalies may be noted by the sonographer:
      • right atrial dilation
      • right ventricle dilation
      • D-shaped septal motion in diastolic
      • dilated IVC and hepatic veins
      • possible thickening of valve leaflets

        Subcostal dilated
        inferior vena cava
    • M-mode
      The following anomalies may be noted by the sonographer:
      • right ventricle dilation
      • paradoxial septal motion

        Parasternal long axis
        paradoxial septal
        motion M-mode
    • Doppler
      When performing Doppler the sonographer would check the presence of:
      • a turbulent jet from the right ventricle to the right atrium in systolic during color Doppler
      • an increased strength of the regurgitant velocity signal compared to the density of the inflow signal during color Doppler
      • possible laminar flow of jet in severe regurgitation cases
      • systolic color Doppler flow reversal in the hepatic veins and IVC
      • an asymmetric shape of the tricuspid regurgitant jet in spectral Doppler
      • due to the rapid equalization of pressures in the right atrium and right ventricle (this is called the "V cut-off" sign) and seen in severe tricuspid regurgitant lesions

        Tricuspid valve
        "V cut-off" sign
        spectral Doppler
  • Quantification of the tricuspid regurgitation severity
    The sonographer performs a number of assessments to determine the degree (mild, moderate, or severe) of aortic regurgitation.
    • jet area ratio (TR jet area/RA area)
    • regurgitant volume/fraction by
      Severity of tricuspid regurgitation Jet area ratio Regurgitant volume Regurgitant fraction
      Mild < 20 % < 20 ml <20%
      Moderate 20-34% 20-40ml 20-40%
      Moderately severe   40-60ml 40-60%
      Severe > 34% > 60 ml > 60 %

2D ultrasound findings

  • an increase in right atrium pressure (RAP) due to tricuspid regurgitation can be measured by assessing the IVC diameter; this increases with increasing disease
  • Criteria for assessing the severity of right atrial pressure are:
    • IVC < 1.7 cm and reduces by more than half with inspiration
    • IVC < 1.7 and reduces by less than half with inspiration
    • IVC diameter does not change with respiration
  • Additional imaging/tests
    • physical examination
    • ECG findings (usually non-specific)
    • chest x-ray
  • Treatment
    • Medication
      • to treat underlying condition
      • to treat arrhythmias
      • to treat heart failure symptoms
    • Surgery
  • Prognosis
    • dependent on severity and prognosis of underlying disorder
  • Complications
    • acute right heart failure
    • ascites
    • cardiac cirrhosis
    • emboli
    • thrombus
    • infection
    • renal failure

Step 4: Pulmonary valve

4.1. Basic physiology

The pulmonary valve is a semilunar valve, with three leaflets, located between the right ventricle and the pulmonary artery. The pulmonary valve opens during systole when pressure in ventricle exceeds pressure in the artery. When blood then flows from the right ventricle into the pulmonary artery, it results in a decrease in pressure in the right ventricle and an increase in pressure in the pulmonary artery. This pressure difference results in the closure of the pulmonary valve, thus preventing blood from flowing back into the right ventricle.


Pulmonary valve

4.2. Pathology

4.2.1. Pulmonary regurgitation

Pulmonary regurgitation (insufficiency) occurs when blood leaks backwards from the pulmonary artery into the right ventricle during diastole, due to the malfunctioning of the pulmonary valve. The condition may be acute or chronic.

Pulmonary hypertension is usually the cause of pulmonary regurgitation, but infective endocarditis is also a predisposing factor.

Severe pulmonary regurgitation may lead to right ventricular hypertrophy and/or dilation and may result in right-sided heart failure. Mild pulmonary regurgitation can be expected in all elderly people and is mainly clinically insignificant.

  • Pathogenesis
    • pulmonary hypertension; dilates the valve ring (most common cause)
    • congenital (eg, pulmonary stenosis, tetralogy of Fallot)
    • rheumatic heart disease
    • carcinoid heart disease
    • infective endocarditis due to AIDS and intravenous (IV) drug abuse
    • traumatic rupture
    • right ventricular infarction
    • ischemic papillary muscle dysfunction
    • right ventricular cardiomyopathy
    • medications
  • Clinical presentation
    • may be asymptomatic
    • dyspnea on exertion
    • fatigue
  • Cardiac auscultation
    • low-pitched diastolic murmur
    • accentuated P2
  • Ultrasound findings
    • 2D
      The following anomalies may be noted by the sonographer:
      • may have thickening of pulmonic leaflets
      • right ventricular volume overload pattern
      • right ventricle pressure overload pattern (septal D-shaped flattening in systole)
    • M-mode
      The following anomalies may be noted by the sonographer:
      • increased LVIDd and LVIDs
      • normal or reduced fractional shortening (FS)


        Parasternal long axis
        left ventricle enlarged
        dimension M-mode

    • Doppler
      When performing Doppler the sonographer would check for the presence of:
      • turbulent jet from the pulmonary artery into the RVOT (visualized using color Doppler)
      • the width of color jet is important not the length from this angle/view (careful with assessment due to beam-width artifact)
      • flow reversal in main pulmonary artery and branches - this indicates a more moderate/severe lesion. It is visualized using color Doppler.
      • increased strength of the regurgitant velocity signal compared with the inflow signal (using spectral Doppler), and a decreased pressure half time of the signal


        Parasternal short axis
        pulmonary regurgitation
        color Doppler

  • Quantification of the pulmonary regurgitation severity
    The sonographer performs a number of assessments to determine the degree (mild, moderate, or severe) of pulmonary regurgitation.
    Severity of pulmonary valve regurgitation Mild Moderate Severe
    Pulmonary valve leaflet appearance normal normal/abnormal abnormal
    Right ventricle size normal normal/dilated dilated
    Jet size (width) narrow and < 10 mm length intermediate large and wide
    Jet density soft dense very dense
    PHT deceleration of jet with CW Doppler slow variable steep
    Pulmonary artery flow slightly increased moderately increased greatly increased
  • Additional imaging/tests
    • physical examination
    • cardiac magnetic resonance to measure the severity of the regurgitation (infrequently used)
    • ECG may demonstrate right ventricular dilation
  • Prognosis
    • dependent on severity and prognosis of underlying disorder
  • Complications
    • right-side heart failure
4.2.2. Pulmonary stenosis

Pulmonary stenosis is a congenital abnormality where blood flow through the pulmonary valve, or right ventricular outflow tract, is restricted. As a result, there is volume and pressure overload of the right ventricle and therefore right ventricular dilation.

  • Pathogenesis
    • congenital pulmonary stenosis (most common)
    • rheumatic heart disease
    • carcinoid heart disease
    • obstructive tumors
    • endocarditis
  • Clinical presentation
    • asymptomatic
    • dyspnea
    • fatigue
    • reduced exercise tolerance
    • cyanosis
    • peripheral edema
    • sudden death
  • Cardiac auscultation
    • harsh systolic ejection murmur
    • widely split S2
  • Ultrasound findings
    • 2D
      The following anomalies may be noted by the sonographer:
      • thickened pulmonary valve leaflets with restricted opening
      • enlargement of the right ventricle
      • hypertrophy of the right ventricular wall
      • post-stenotic dilation of the main pulmonary artery
      • "D-shaped" flattening interventricular septal motion due to right ventricular pressure overload
      • possible enlargement of the right atrium and inferior vena cava (IVC)


        Parasternal short axis
        post stenotic dilation
        of pulmonary artery 2D

    • M-mode
      The following anomalies may be noted by the sonographer:
      • increased RVIDd
      • normal LVIDd and LVIDs
      • normal fractional shortening (FS)


        Parasternal long axis
        normal ventricles M-mode

    • Doppler
      When performing Doppler the sonographer would check for the presence of:
      • a turbulent jet leading into the pulmonary artery (visualized using color Doppler)
      • a dense turbulent jet (visualized using spectral Doppler)
      • increased forward flow velocities > 1m/sec
      • a subvalvular or supra-valvular stenotic lesion (visualized using pulsed-wave Doppler)
      • tricuspid regurgitation with elevated peak flow consistent with elevated right ventricular pressures


        Parasternal short axis
        pulmonary artery dense
        turbulent jet color Doppler

  • Quantification of the pulmonary stenosis severity
    The sonographer performs a number of assessments to determine the degree (mild, moderate, or severe) of pulmonary stenosis.
    Severity Peak velocity Peak pressure gradient Valve area
    Mild < 3 m/s < 30 mmHg > 2 cm2
    Moderate 3-4 m/s 30-64 mmHg 1-2 cm2
    Severe > 4 m/s > 64 mmHg < 1 cm2
  • Additional imaging/tests
    • physical examination
    • pulmonary angiography may demonstrate domed leaflets
    • ECG is usually normal in mild pulmonary stenosis but right ventricle hypertrophy may be noted as severity increases
    • chest x-ray may demonstrate a normal sized heart but a possible prominent pulmonary artery
    • Cardiac catheterization is indicated only if pulmonary stenosis is severe
  • Treatment
    • Medicine
      • to treat underlying condition
      • to treat heart failure symptoms
    • Surgical
      • balloon valvuloplasty to stretch and open the valve
      • valvotomy
      • balloon angioplasty, with or without stent
  • Prognosis
    • dependent on severity and prognosis of underlying disorder
  • Complications
    • right heart failure
    • endocarditis

References

Textbooks
Reynolds T. The Echocardiographer's Pocket Reference. 3rd ed. Phoenix, Arizona: Arizona Heart Institute; 2007: 9, Table 2: Echo Score Index for Mitral Stenosis.

Bibliography

Textbooks

Anderson B. Echocardiography: The Normal Examination and Echocardiographic Measurements. 1st ed. MGA Graphics; 2000.

Feigenbaum H, Armstrong F, Ryan T. Feigenbaum's Echocardiography. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2005.

Kaddoura S. Echo Made Easy. 2nd ed. St Louis, MO: Churchill Livingstone Elsevier; 2009.

Oh J, Seward J, Tajik A. The Echo Manual. 2nd ed. Philadelphia, PA: Lippincott-Raven; 1999.

Otto C. Textbook of Clinical Echocardiography. 2nd ed. Philadelphia, PA: WB Saunders Company; 2000.

Reynolds T. The Echocardiographer's Pocket Reference. 3rd ed. Phoenix, Arizona: Arizona Heart Institute; 2007.

Web articles

Bayne E. Aortic valve, bicuspid. eMedicine.
Available at: http://emedicine.medscape.com/article/893523-overview
Accessed April 13, 2010.

Dima C, Desser K, Nachimuthu S, Balasundaram K. Mitral stenosis. eMedicine.
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Accessed April 13, 2010.

Fogel M, Zieve D. Bicuspid aortic valve. MedlinePlus.
Available at: http://www.nlm.nih.gov/medlineplus/ency/article/007325.htm
Accessed April 13, 2010.

Mancini M. Tricuspid regurgitation. eMedicine.
Available at: http://emedicine.medscape.com/article/158484-overview
Accessed April 13, 2010.

Mancini M. Tricuspid stenosis. eMedicine.
Available at: http://www.emedicine.medscape.com/article/158604-overview
Accessed March 6, 2010.

Ren X, Cannistra L. Pulmonic regurgitation. eMedicine.
Available at: http://emedicine.medscape.com/article/157639-overview
Accessed April 13, 2010.

Ren X, Cannistra L. Pulmonic stenosis. eMedicine.
Available at: http://emedicine.medscape.com/article/157737-overview
Accessed April 13, 2010.

Singh V. Mitral valve prolapse. Emedicinehealth.
Available at: http://www.emedicinehealth.com/mitral_valve_prolapse/article_em.htm
Accessed April 13, 2010.

Tanser P. Tricuspid regurgitation. The Merck Manuals Online Medical Library.
Available at: http://www.merck.com/mmhe/sec03/ch028/ch028g.html
Accessed April 13, 2010.

Weinrauch L, Zieve D. Aortic insufficiency. MedlinePlus.
Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000179.htm
Accessed April 13, 2010.

Weinrauch L, Zieve D. Mitral stenosis. MedlinePlus.
Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000175.htm
Accessed April 13, 2010.

Zevitz M. Cardiomyopathy, hypertrophic. eMedicine.
Available at: http://emedicine.medscape.com/article/152913-overview
Accessed April 13, 2010.

Websites

Cardiovascular Consultants. Heart anatomy. Physiology.
Available at: http://www.cardioconsult.com/Anatomy/
Accessed April 13, 2010.

Echocardiology.org: Echocardiography tutorials. Valvular Disease.
Available at: www.echocardiology.org
Accessed April 13, 2010.

Mayo Clinic. Hypertrophic Cardiomyopathy.
Available at: http://www.mayoclinic.org/hypertrophic-cardiomyopathy/
Accessed April 13, 2010.

Mitral Valve Repair Center at The Mount Sinai Hospital. The Mitral Valve. Mitral Valve Function.
Available at: http://www.mitralvalverepair.org/content/view/55/
Accessed April 13, 2010.

The American Society of Echocardiography. ASE Guidelines and Standards.
Available at: www.asecho.org
Accessed April 13, 2010.

U.S. Department of Health & Human Service. Health Information Privacy. The Health Insurance Portability Act of 1996 (HIPPA) Privacy Rule.
Available at: http://www.hhs.gov/ocr/privacy/index.html
Accessed March 4, 2010.