Valvular Abnormalities and Disease
Four Considerations When Evaluating Cardiac Valves:
  1. How many valve leaflets are present?
  2. Do you see abnormal masses, thickening or calcification attached to the valve leaflets?
  3. Is leaflet mobility normal, restricted or hypermobile?
  4. What are the associated abnormalities of the cardiac chambers and other cardiac valves?

Clinical Symptoms:
  • Palpitations
  • Fatigue
  • Dizziness
  • Dyspnea
  • Systolic murmur
  • Systolic ejection click

AORTIC VALVE ABNORMALITIES



Aortic Stenosis - Atherosclerosis:

  • Varying degrees of leaflet thickening will be demonstrated
  • Fusion of the edges of the leaflets may occur with severe stenosis
  • Hypertrophy of the muscle wall of the ventricle will occur as it adapts to the chronic pressure overload
M-mode:
  • Used to assess systolic leaflets separation
  • <12 mm cusp separation indicates significant obstruction
  • Method is not very accurate in determining the severity of the stenosis
  • Thickened leaflets cause multiple echoes to be displayed in diastole
  • Decreased leaflet separation and multiple echoes filling the space between the aortic root and AV opening
  • LVH due to pressure overload
  • Post stenotic aortic root dilatation due to eccentric flow through stenosis
2D and Doppler Evaluation:
  • PLAX - delineates the restricted opening of the tips of the aortic leaflets
  • PSAX - at the level of the aortic valve demonstrates the true orifice of the stenotic valve ; area can be traced, ****planimetry is not very accurate because heavily calcified leaflets cause bright echoes with poorly defined borders making measurement difficult
  • AP 5/AP 3 – Doppler evaluation of the LVOT and AV velocities
  • Pedoff probe applied at the apical, right parasternal and suprasternal windows
Peak Pressure Gradient (PPG):
  •      Mild (normal or increased cardiac output) <36 mmHg
  •      Moderate 37-80 mmHg
  •      Severe (normal or depressed cardiac output) >80 mmHg
Mean Pressure Gradient (MPG):
  •      Mild (normal or increased cardiac output) <20mmHg
  •      Moderate 21-40mmHg
  •      Severe (normal or depressed cardiac output) >40 mmHg
  •      Critical- >50 mmHg
  • Average normal aortic valve area is 3cm²
  • Average PSV 1.4m/s
  • Increasing velocities and acceleration times are noted with increasing severity of stenosis
  • Aortic flow may be recorded from the apical, suprasternal or parasternal locations
  • Velocity and PPG alone cannot diagnose stenosis due to variations in cardiac output, you must know the valve area
  • Mild:                PSV 2 – 3m/s;           PPG <36mmHg
  • Moderate:      PSV 3 – 4m/s;           PPG 36 – 80mmHg
  • Severe:            PSV >4m/s;               PPG >80mmHg
  • Valve area calculated by continuity equation (independent of cardiac output, NOT affected by regurge):
       >        Mild:  1.5 – 2.0cm
       >        Moderate:  0.7 - 1.5 cm
       >        Severe:  <0.7 cm
  • V1 / V2 ratio (independent of cardiac output):
       >        Severe stenosis:   <0.25 
Associated Abnormalities:
  • LVH
  • Dilated aortic root
  • Turbulence distal to the valve
Rheumatic Heart Disease:
  • Valvular degeneration and thickening from rheumatic heart disease usually affects BOTH the AV and MV where atherosclerotic disease usually affects one valve or the other.
  • May cause MS/MR and/or AS/AI
Congenital Aortic Stenosis:

  • Usually involves and abnormal leaflet number with restricted movement
  • Can be unicuspid, bicuspid or quadricuspid
  • Some bicuspid valves are composed of 3 leaflets with 2 fused together causing decreased AVA/stenosis
  • Most common congenital defect detected in adults
  • Leaflet composed of only two flaps instead of three
  • Doming of leaflets during systole
  • Aortic regurgitation is common
  • Dilatation of the aortic root and ascending aorta may occur
  • Short axis view of the heart best any demonstrates abnormal valve structure
  • Associated with coarctation, Marfan's syndrome, aortic root dilatation
Membranous Subvalvular Aortic Stenosis:
  • Membranous band of tissue arising in the ascending aorta near the aortic valve
  • Tissue obstructs left ventricular ejection and will stimulate aortic valve stenosis
  • Compensatory left ventricular hypertrophy may occur
  • Membranous supravalvular band is rarely observed on the echocardiogram
AV Regurgitation/Insufficiency:
  • Palpitations
  • Pain
  • Fatigue
  • Dyspnea
  • Diastolic murmur
  • Austin Flint murmur - severe AI; low frequency diastolic murmur
Symptoms:
  • Chest pain
  • Orthopnea: difficulty breathing when supine
  • Cough
  • Caused by flail leaflets
  • Normal left ventricle size with vigorous contractility
  • Fluttering of the anterior leaflet of MV in diastole
  • May see premature closure of the MV
  • Flow starts before the mitral valve opens and continues until shortly after it closes
  • Best recorded with a transducer in apical position or from a suprasternal location
Chronic AV Regurgitation:
Causes:
  • Inadequate leaflet coaptation
  • Ruptured leaflet or vegetation
  • Dilatation of the valve annulus
  • Bacterial endocarditis
  • Fibrosis/Calcification of the leaflets
  • Rheumatic heart disease
  • Chronic volume overload of the left ventricle may cause dilatation
Acute AV Regurgitation:
Color Doppler:
If the regurgitation jet fills LVOT at a ratio:
  • <30% suggests mild regurgitation
  • 30% to 60% suggests moderate regurgitation
  • >60% suggests severe regurgitation 
2D/M-mode:
  • Mild: Little to no effect
  • Moderate/Severe:  LV dilatation and hypercontractility, mild LA enlargement
  • Early MV closure and diastolic fluttering of the AV leaflets seen on m-mode w/ severe AI
  • May cause IVS fluttering and anterior MV leaflet vibration in diastole due to eccentric jet
CW Doppler:
  • Pressure half-time of the E-F slope of the Doppler tracing used to assess pressure half time and deceleration time
  • Pressure half-time:
       >        Mild- >500 msec
       >        Moderate- 200-500 msec
       >        Severe- <200 msec
  • Moderate : early diastolic flow reversal in descending aorta
  • Severe: flow reversal throughout diastole in the descending aorta
Mitral Stenosis:

  • Most common cause: Rheumatic heart disease
  • Rheumatic fever caused by infection by beta hemolytic streptococci, symptoms include fever, joint pain, arthritis, endocarditis, pericarditis
  • Other causes include degenerative disease and congenital stenosis
Clinical Symptoms:
  • Dyspnea on exertion
  • Nocturnal dyspnea
  • Orthopnea
  • Hemoptysis
  • Systemic embolism
  • Palpitations/A-fib
  • Loud S1 and diastolic "rumbling" murmur
  • Snapping sound due to limitations in valve motion upon opening
Sonographic Appearance:
  • Leaflets have a domed appearance in diastole due to leaflet tip fusion
  • The anterior leaflet may pull the posterior leaflet forward in diastole
  • M mode demonstrates a thickened line with a decrease in the E-F slope and E amplitude due to decreased leaflet motion (Doppler demonstrates an increase in the E wave amplitude with MS; measures velocity)
  • PSAX at level of the mitral valve demonstrates the true orifice of the stenotic valve and the area can be measured
  • Planimetry is preferred method of assessment but unfortunately is not obtainable on all patients
  • CW Doppler assessment in AP 4 view, slope of E wave measured for pressure half time
  • Average normal area of mitral valve in adults is 5cm²
  • Average velocity range 0.6 – 1.4 m/s
  • Mitral flow is best recorded with the transducer in apical position and the cursor placed perpendicular to tips of the MV leaflets
  • E-F slope is decreased which reflects a reduced rate of emptying of the left atrium
  • E and A velocities will be increased
  • Most patients with a severe degree of mitral stenosis develop atrial fibrillation due to atrial stretching; Doppler recordings will display a loss of the A wave
  • Valve area determined by planimetry (most accurate) and/or diastolic pressure half-time (easiest to perform)
  • Pressure half time refers to the time it takes for the peak mitral pressure to decrease by 1/2
  • Allows for the mean pressure gradient calculation also
  • Measure the slope of the descent of the E wave velocity
  • Be sure to measure the portion of the waveform that demonstrates the slow deceleration caused by the stenosis
Mitral Valve Area (MVA):
P ½ time = <150ms
P ½ time = 150-220ms
P ½ time = >220ms

Associated Abnormalities:

  • LA dilation
  • Thrombus formation in LA
  • Dilated RV due to pulmonary HTN caused by persistently elevated LA pressure
  • Severe MR may cause innaccurate P1/2 time measurements and volume overload of the LV
Mitral Annular Calcification (MAC):
  • Most commonly observed by the sixth decade of life
  • Usually seen with aortic sclerosis/stenosis, HOCM, severe chronic hyperparathyroidism, renal failure
  • Annulus is continuously subjected to shearing forces related to ventricular contraction which may cause fibrosis and calcification to occur
  • Distinguished from Rh fever by calcification placement, MAC usually does not affect valve leaflets where Rh fever causes fibrosis of the valve leaflets
Chronic MR:
Clinical Symptoms:
  • Usually asymptomatic
  • Atypical chest pain
  • Palpitations
  • Fatigue
  • Dyspnea unrelated to exertion
  • Severe MR leads to pulmonary edema

Causes:
  • Abnormalities of the annulus, leaflets, chordae tendonae and papillary muscles
  • MVP
  • Calcification of the annulus, chordate tendonae and papillary muscles
  • Bacterial endocarditis with rupture of the chordate tendonae
  • Ischemia or infarction of the papillary muscles
  • Can occur with any condition that causes severe dilatation of the left ventricle which in turn dilates the valve and related structures leading to valve incompetence

Acute MR:
  • Causes include flail mitral leaflet and rupture of papillary muscle with acute MI
  • Symptoms are sudden breathlessness, productive coughing, pulmonary edema
Associated Findings:
  • Increased LA size and pressure
  • Pulmonary HTN
  • RV dilatation/hypertrophy
Mitral Regurgitation (MR):
Color Doppler Assessment:
  • Determined by visual assessment of percent of LA occupied by regurgitant jet volume
  • Mild- <10%
  • Moderate- 10-40%
  • Severe- >40%
  • PISA measurements - Proximal Isovelocity Surface Area; the greater the radius of the area of flow convergence at the leaflet tips, the greater the rate of regurge present; MR PISA radius squared = area; PISA Area X Velocity = regurgitant flow rate

CW Doppler Assessment:
  • Used to asses flow patterns related to pressure gradients
  • The high pressure spiked jets are a lesser degree of regurge than the rounded waveforms seen with lower pressure jets from greater degrees of regurge; Larger "openings" yield lower pressure gradients
Parachute MV:
  • Congenital anomaly
  • One papillary muscle attached to both sets of chordae for both leaflets
  • Usually the posteromedial muscle is the only one present
  • Presents like MS on echo/Doppler
Double Orifice MV:
  • Accessory orifice
  • PSAX best to visualize
  • Flow evaluation may be normal or appear with signs of  stenosis/regurge
Supravalvular MV Stenosis (Ring):
  • A membrane located at the level of the MV annulus obstructs LV inflow
  • Associated w/ ASD, VSD, coarctation, persistent left SVC and Shone’s complex
Cor Triatriatum:
  • Membrane  across the mid portion of the LA disrupts flow from atrium through MV
  • Mimics MS with turbulent flow, increased PSV and PPG
  • 80% have ASD also
  • Can also be found in the right atrium but less frequently
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Symptoms:
Congenital Mitral Valve Abnormalities:
Cleft MV:

  • Most commonly occurs with atrio-ventricular septal defect (AVSD)
  • PSAX view shows a division of its anterior leaflet
  • Results in MR
  • PLAX view shows the anterior mitral leaflet doming during diastole, BUT there is no stenosis of the valve
Mitral Valve Prolapse (MVP):
  • Degenerative, myxomatous disease of the leaflets; >5mm thickness in diastole
  • Demonstrated on M mode as posterior motion of the mitral leaflet in mod to late systole
  • Best visualized in parasternal long axis view
  • Valve leaflet falls >2mm below the annular plane
  • Clicking murmur
  • Usually has associated MR causing increased LA size
  • Increased risk of endocarditis
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MITRAL VALVE ABNORMALITIES
Supravalvular Aortic Stenosis:
  • Narrowed aortic root lumen causing stenosis
  • Usually caused by abnormal fibrous tissue accumulation or inflammation
  • Can be caused by Takayasu's Arteritis
  • Increased velocity in the affected segment with normal AV motion
  • CT/MR useful in making disgnosis due to limited sonographic windows in some patients
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  •       Mild- 1.6-2.5 cm2
  •       Moderate- 1.0-1.5 cm2
  •       Severe- <1.0 cm2
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Bicuspid AV: