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Fuad Farooq
 Aortic valve is composed of three cusps of equal size, each ofwhich is surrounded by a sinus Cusps are separated by thr...
 Free edge of each cusp curves upward from the commissureand forms a slight thickening at the tip or midpoint, calledthe ...
When viewed from a2D echo parasternalshort-axis projection,these three lines ofclosure are seen as an“inverted MercedesBen...
 Behind each cusp is its associated Valsalva sinus Sinuses represent outpunching in the aortic root directlybehind each ...
Left and right coronary arteries arise from the left and rightsinuses, respectively, and are associated with the left andr...
The area of a normal aortic valve is 3 to 4 cm2Normal opening generally produces 2 cm ofleaflet separation Maintained thr...
The most common form of aortic stenosis iscaused by degenerative valvular calcification Leaflets are thickened and calcif...
 Establishing the diagnosis Quantifying severity Assessing left ventricular function Identify concomitant valvular abn...
 Visualizes the entire aortic valve structure Helpful in identifying noncalcific as well as calcific aorticstenosis Deg...
 Cusps are thickened and showed restricted mobility Their position during systole is no longer parallel to the aorticwal...
Unfortunately only give qualitativeassessment and attempts to quantify thedegree of stenosis based on two-dimensionalechoc...
Rheumatic Heart disease
Unicuspid Aortic Valve
Bicuspid Aortic Valve
Bicuspid Aortic Valve
Bicuspid Aortic Valve
Bicuspid Aortic Valve
Quardicuspid Aortic Valve
Subaortic Membrane
Subaortic Membrane
Hemodynamic assessment of severity of aorticstenosis determined with Doppler echo is based on Peak aortic flow velocity ...
Meticulous search for the maximal aortic velocity isessential because all the variables are derived fromthe peak aortic fl...
 Peak velocity usually occurs in mid systole As aortic stenosis worsens, velocity tends to peaklater in systole Offerin...
Blood flow velocity and pressure gradientincrease as the valve becomes smaller as longas stroke volume remains constant
Blood flow velocity (v) measured with Dopplerechocardiography reliably reflects the pressuregradient according to the modi...
 Often obtained by planimetry of the Dopplerenvelope Mean gradients can also be calculated as:Mean gradients = Peak grad...
 A technically poor recording may fail to display thehighest velocity signals Resulting in underestimation of the true g...
 Overestimation of the true pressure gradient is less commonbut can occur Result of mistaken identity of the recorded si...
Valve gradients are dynamic measurements thatvary with Heart rate Loading conditions Blood pressure Inotropic state
For a given valve area, flow velocity and pressuregradient vary with the change in stroke volume andcardiac output Cardia...
Hydraulic formulaFlow = Area x Flow velocityThe continuity equation use lawof conservation of mass,states that, “what goes...
For calculating aortic valve area followingmeasurements must be performed Cross-sectional area of the LVOT Time velocity...
Continuity equation has advantages over Bernoulliequation for the assessment of aortic stenosis Not affected by the prese...
Potential factors that may contribute to errorsinclude Image quality Annular calcification (which obscures the true dime...
 Always preferable Because VTI or peak velocity ratio is inverselyproportional to the area ratio of the LVOT andaortic v...
 Velocity or TVI ratio is independent of any change instroke volume because the LVOT and aortic valvevelocities change pr...
In patients with normal LV systolic functionand cardiac output, aortic stenosis is usuallysevere when Peak aortic valve v...
 LV dysfuction with severe AS than two diagnosticpossibilities: True anatomically severe aortic stenosis Functionally s...
Gradual infusion of dobutamine (up to 20µg/kg/minute) to increase stroke volume may behelpful in differentiating morpholog...
 Dobutamine infused gradually from 5 µg/kg/minutein 5µg increments every 3 minutes until the LVOTvelocity or VTI reaches ...
 In true severe AS, the infusion of dobutamineincreases the peak velocity and VTI of both theLVOT and aortic valve propor...
LVOT VTI : Aortic valve VTI = 0.22 LVOT VTI : Aortic valve VTI = 0.22True aortic stenosis
 When LV systolic function is abnormal and cardiacoutput is reduced, aortic stenosis is probably severeif Aortic valve a...
 Another most important role of dobutamine infusion inpatients who have severe aortic stenosis and a low gradientis to as...
 If Dobutamine infusion is able to increase strokevolume (or LVOT VTI) by 20% or more and theaortic valve area remains 1....
 If transthoracic is difficult to perform TEE can be used to measure aortic valve area byplanimetry The number of aorti...
 Diastolic function varies in patients with aorticstenosis Usually have at least a mild degree (grade 1) ofdiastolic dys...
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
Aortic stenosis
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Aortic stenosis

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Aortic stenosis

  1. 1. Fuad Farooq
  2. 2.  Aortic valve is composed of three cusps of equal size, each ofwhich is surrounded by a sinus Cusps are separated by three commissures and supported bya fibrous anulus Each cusp is crescent shaped and capable of opening fully toallow unimpeded forward flow, then closing tightly toprevent regurgitation
  3. 3.  Free edge of each cusp curves upward from the commissureand forms a slight thickening at the tip or midpoint, calledthe Arantius nodule When the valve closes, the three nodes meet in the center,allowing coaptation to occur along three lines that radiate outfrom this center point Overlap of valve tissue along the lines of closure produces atight seal and prevents backflow during diastole
  4. 4. When viewed from a2D echo parasternalshort-axis projection,these three lines ofclosure are seen as an“inverted MercedesBenz sign”Normal leaflets are sodelicate that they arehard to visualize,generally an indicationthat they aremorphologicallynormal
  5. 5.  Behind each cusp is its associated Valsalva sinus Sinuses represent outpunching in the aortic root directlybehind each cusp Function to support the cusps during systole and provide areservoir of blood to augment coronary artery flow duringdiastole
  6. 6. Left and right coronary arteries arise from the left and rightsinuses, respectively, and are associated with the left andright aortic cuspsThird, or noncoronary sinus, isposterior and rightward, justabove the base of the interatrialseptum, and is associated withthe noncoronary aortic cuspRCCLCCNCCLALAARARVOTRV
  7. 7. The area of a normal aortic valve is 3 to 4 cm2Normal opening generally produces 2 cm ofleaflet separation Maintained throughout the cardiac cycle until lowcardiac output or LVOT obstruction
  8. 8. The most common form of aortic stenosis iscaused by degenerative valvular calcification Leaflets are thickened and calcified Decreasing systolic openingOther causes includebicuspid aortic valveand rheumatic heartdisease
  9. 9.  Establishing the diagnosis Quantifying severity Assessing left ventricular function Identify concomitant valvular abnormalities
  10. 10.  Visualizes the entire aortic valve structure Helpful in identifying noncalcific as well as calcific aorticstenosis Degree of valvular calcification, the size of the aorticanulus and the supravalvular ascending aorta, and thepresence of secondary subvalvular obstruction are easilyevaluated Useful for determining the degree of LV hypertrophy(wall thickness and mass), LA enlargement, ventricularfunction, and the integrity of the other valves
  11. 11.  Cusps are thickened and showed restricted mobility Their position during systole is no longer parallel to the aorticwalls, and the edges are often seen to point toward thecenter of the aorta In severe cases, a nearly total lack of mobility may be presentand the anatomy may become so distorted thatidentification of the individual cusps is impossible
  12. 12. Unfortunately only give qualitativeassessment and attempts to quantify thedegree of stenosis based on two-dimensionalechocardiographic findings have beenunsuccessful
  13. 13. Rheumatic Heart disease
  14. 14. Unicuspid Aortic Valve
  15. 15. Bicuspid Aortic Valve
  16. 16. Bicuspid Aortic Valve
  17. 17. Bicuspid Aortic Valve
  18. 18. Bicuspid Aortic Valve
  19. 19. Quardicuspid Aortic Valve
  20. 20. Subaortic Membrane
  21. 21. Subaortic Membrane
  22. 22. Hemodynamic assessment of severity of aorticstenosis determined with Doppler echo is based on Peak aortic flow velocity Mean pressure gradient Aortic valve area LVOT and aortic valve (AoV) velocity time integral (VTI)ratio (LVOTVTI: AoV VTI)
  23. 23. Meticulous search for the maximal aortic velocity isessential because all the variables are derived fromthe peak aortic flow velocity All available transducer windows should be used to obtain theDoppler signal most parallel with the direction of the jet flow,which provides the highest velocity recording Failure to achieve parallel alignment will result inunderestimation of true velocity Nonimaging continuous wave Doppler transducer is smaller andthus easier to manipulate between the ribs and suprasternalnotch
  24. 24.  Peak velocity usually occurs in mid systole As aortic stenosis worsens, velocity tends to peaklater in systole Offering a clue to severity
  25. 25. Blood flow velocity and pressure gradientincrease as the valve becomes smaller as longas stroke volume remains constant
  26. 26. Blood flow velocity (v) measured with Dopplerechocardiography reliably reflects the pressuregradient according to the modified Bernoulliequation (give peak instantaneous gradientsbecause Doppler measure velocity over time)Pressure gradient = 4v2
  27. 27.  Often obtained by planimetry of the Dopplerenvelope Mean gradients can also be calculated as:Mean gradients = Peak gradient/1.45 + 2
  28. 28.  A technically poor recording may fail to display thehighest velocity signals Resulting in underestimation of the true gradient An inability to align the interrogation angle parallelto flow also results in underestimation
  29. 29.  Overestimation of the true pressure gradient is less commonbut can occur Result of mistaken identity of the recorded signal e.g., MRjet has a contour similar to that of a jet of severe AS Avoid by sweeping the transducer back and forth to clearlyindicate to the interpreter which jet is which Another helpful clue involves the timing of the two jets MR islonger in duration, beginning during isovolumic contractionand extending into isovolumic relaxation
  30. 30. Valve gradients are dynamic measurements thatvary with Heart rate Loading conditions Blood pressure Inotropic state
  31. 31. For a given valve area, flow velocity and pressuregradient vary with the change in stroke volume andcardiac output Cardiac output or stroke volume should be taken intoaccount when the severity of valvular stenosis isdetermined
  32. 32. Hydraulic formulaFlow = Area x Flow velocityThe continuity equation use lawof conservation of mass,states that, “what goes inmust come out” Reliably estimate valve area
  33. 33. For calculating aortic valve area followingmeasurements must be performed Cross-sectional area of the LVOT Time velocity integral of the LVOT Time velocity integral of the aortic stenosis jet
  34. 34. Continuity equation has advantages over Bernoulliequation for the assessment of aortic stenosis Not affected by the presence of aortic regurgitation Continuity equation is relatively unaffected and will allowan accurate estimation of valve area whether the strokevolume is normal or reduced
  35. 35. Potential factors that may contribute to errorsinclude Image quality Annular calcification (which obscures the true dimension) Noncircular anulus (which invalidates the formula) Failure to measure the true diameter
  36. 36.  Always preferable Because VTI or peak velocity ratio is inverselyproportional to the area ratio of the LVOT andaortic valve Also useful in determining the severity of aorticstenosis
  37. 37.  Velocity or TVI ratio is independent of any change instroke volume because the LVOT and aortic valvevelocities change proportionally Also helpful in the presence of aortic regurgitationNormal Ratio > 0.75
  38. 38. In patients with normal LV systolic functionand cardiac output, aortic stenosis is usuallysevere when Peak aortic valve velocity is 4 m/s Mean pressure gradient is 40 mm Hg Aortic valve area is less then 1 cm2 LVOTVTI: AoVVTI is 0.25
  39. 39.  LV dysfuction with severe AS than two diagnosticpossibilities: True anatomically severe aortic stenosis Functionally severe aortic stenosis (pseudosevere) Because an aortic valve with mild or moderatelysevere stenosis may not open fully if the strokevolume is low
  40. 40. Gradual infusion of dobutamine (up to 20µg/kg/minute) to increase stroke volume may behelpful in differentiating morphologically severeaortic stenosis from a decreased effective stenoticorifice area caused by low cardiac output(pseudosevere aortic stenosis)
  41. 41.  Dobutamine infused gradually from 5 µg/kg/minutein 5µg increments every 3 minutes until the LVOTvelocity or VTI reaches a normal value i.e., 0.8 to 1.2m/s or 20 to 25 cm, respectively Maximal velocity or stroke volume is usuallyobtained with 15 to 20 µg/kg/minute of dobutamine
  42. 42.  In true severe AS, the infusion of dobutamineincreases the peak velocity and VTI of both theLVOT and aortic valve proportionally (hence, theLVOTVTI: AoV VTI remains constant) In pseudosevere AS increase in velocity and VTI ofthe LVOT is far greater than that of the aortic valvehence, LVOTVTI : AoVVTI increases
  43. 43. LVOT VTI : Aortic valve VTI = 0.22 LVOT VTI : Aortic valve VTI = 0.22True aortic stenosis
  44. 44.  When LV systolic function is abnormal and cardiacoutput is reduced, aortic stenosis is probably severeif Aortic valve area by the continuity equation is 1.0 cm2orless LVOTVTI :AoVVTI is 0.25 or less
  45. 45.  Another most important role of dobutamine infusion inpatients who have severe aortic stenosis and a low gradientis to assess inotropic reserve Defined as an increase in stroke volume of more than 20% withdobutamine Lack of inotropic reserve with dobutamine portends poorperioperative mortality (50% vs. 7%) if aortic valvereplacement is attempted
  46. 46.  If Dobutamine infusion is able to increase strokevolume (or LVOT VTI) by 20% or more and theaortic valve area remains 1.0 cm2or less, aortic valvereplacement should be recommended If no inotropic reserve is demonstrated withdobutamine, aortic valve replacement is still betterthan no treatment, but the mortality rate is veryhigh
  47. 47.  If transthoracic is difficult to perform TEE can be used to measure aortic valve area byplanimetry The number of aortic cusps can be determined Not routine practice to use TEE to evaluate aorticstenosis Intraoperatively in AVR for assessment of severityof MR and need for mitral valve replacement
  48. 48.  Diastolic function varies in patients with aorticstenosis Usually have at least a mild degree (grade 1) ofdiastolic dysfunction As aortic stenosis progresses to a symptomaticstage, diastolic function also deteriorates to grades2 and 3

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