Tissue doppler imaging

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  • Figure 1 Pulsed tissue Doppler imaging (TDI) with the sample gate placed at the lateral base of the left ventricular wall in the apical 4-chamber view. The top portion of the figure demonstrates excessive spectral gain and overestimation of the systolic and diastolic myocardial velocities. The bottom portion shows proper gain and measurements of the systolic velocity (V1) , early diastolic (V2) , and late diastolic (V) velocities. LV, Left ventricle.
  • Tissue doppler imaging

    1. 1. Tissue Doppler ImagingTissue Doppler ImagingDr.Hafeez AhmedDr.Hafeez Ahmed
    2. 2. DOPPLER SIGNALSDOPPLER SIGNALS• Blood flow Doppler signalsBlood flow Doppler signals ►► highhighvelocities and low amplitudevelocities and low amplitude• Myocardial wall Doppler signalsMyocardial wall Doppler signals ►► lowlowvelocities & high amplitudevelocities & high amplitude• Amplitude of tissue motion is about 40 dbAmplitude of tissue motion is about 40 dbgreater than the flow amplitudegreater than the flow amplitude
    3. 3. • For conventional DopplerFor conventional Doppler →→ high-passhigh-passfilterfilter →→ prevent high-amplitude signalprevent high-amplitude signaldetection from myocardiumdetection from myocardium• For TDIFor TDI• ►► this filter is bypassedthis filter is bypassed• ►►high frequency blood flow signalshigh frequency blood flow signalseliminated by gain adjustmenteliminated by gain adjustment
    4. 4. • Spectral gain settings must be reducedSpectral gain settings must be reduced• Scale must be corrected (<25 cm/sec)Scale must be corrected (<25 cm/sec)• Myocardial area of interest should be placed inMyocardial area of interest should be placed inthe center of the US beamthe center of the US beam• Nyquist limit -20 to 30 cm/secNyquist limit -20 to 30 cm/secInstrumentation & TechniqueInstrumentation & Technique
    5. 5. High spectral gain
    6. 6. Types of Tissue DopplerTypes of Tissue Doppler• Pulsed wave tissue dopplerPulsed wave tissue doppler• Color tissue dopplerColor tissue doppler– M modeM mode– 2D2D●● Strain Rate imagingStrain Rate imaging●● Myocardial velocity GradientMyocardial velocity Gradient
    7. 7. Color TDIColor TDI• Doppler signalsDoppler signals →→ frequencyfrequency →→ digitaldigital• formatformat →→ autocorrelationautocorrelation →→ differentdifferentvelocitiesvelocities →→ preset color schemepreset color scheme →→superimposed on 2-D gray scalesuperimposed on 2-D gray scale
    8. 8. • Color TDI :Color TDI :• Increased spatial resolutionIncreased spatial resolution• Evaluate multiple structures and segmentsEvaluate multiple structures and segmentsin a single viewin a single view
    9. 9. Tissue velocityTissue velocity• Upper limit of measurable velocities isUpper limit of measurable velocities isdetermined by the pulse repetitiondetermined by the pulse repetitionfrequencyfrequency• 2D-Color TDI measures average tissue2D-Color TDI measures average tissuevelocityvelocity• Wall motion velocity at rest : 10 cm/s orWall motion velocity at rest : 10 cm/s orlessless• During stress:During stress: ↑ 15 cm/s↑ 15 cm/s• Aliasing unlikelyAliasing unlikely
    10. 10. Frame RateFrame Rate• Temporal and spatial resolutionTemporal and spatial resolutiondependent ondependent on → doppler shift →→ doppler shift → frameframeraterate→→ 1)probe frequency 2) pulse1)probe frequency 2) pulserepetition frequency 3) sector anglerepetition frequency 3) sector angle• Frame rates of up to 240/s can beFrame rates of up to 240/s can beobtainedobtained
    11. 11. How to Optimize Color DopplerHow to Optimize Color DopplerRecordingsRecordings• Velocities are always measured in-lineVelocities are always measured in-linewith the ultrasound beamwith the ultrasound beam• Narrowing the sector angle and reducingNarrowing the sector angle and reducingimage depth increases the tissue Dopplerimage depth increases the tissue Dopplerframe rate and, thus, temporal resolutionframe rate and, thus, temporal resolutionof the reconstructed velocity curvesof the reconstructed velocity curves• Frame rates of at least 120 frames/Frame rates of at least 120 frames/second are recommendedsecond are recommended
    12. 12. Pulsed Wave Tissue DopplerPulsed Wave Tissue DopplerImagingImaging• Pulsed-wave-TDI measures peak velocityPulsed-wave-TDI measures peak velocityinstantaneouslyinstantaneously• High temporal resolutionHigh temporal resolution• Lower reproducibilityLower reproducibility
    13. 13. Sample volumeSample volume• Sample volumesSample volumes→→ positioned into thepositioned into theregion of interest within the myocardiumregion of interest within the myocardium• An average of all mean velocities ofAn average of all mean velocities oftissues moving within the sample regiontissues moving within the sample regionare determinedare determined• Small sample volumeSmall sample volume
    14. 14. • Doppler signals are converted into singleDoppler signals are converted into singleor multiple velocity curvesor multiple velocity curves• By Fourier analysis mean peak systolicBy Fourier analysis mean peak systolicand diastolic velocities are generatedand diastolic velocities are generated• velocities are measured as cm/s and timevelocities are measured as cm/s and timeintervals in millisecondsintervals in milliseconds• adjustments of the scale and sweep speedadjustments of the scale and sweep speedto optimize the spectral displayto optimize the spectral display
    15. 15. • The systolic phase represented by a positiveThe systolic phase represented by a positivewave (S) preceded by isovolumic contractionwave (S) preceded by isovolumic contraction(RIVCT) spike(RIVCT) spike• The diastolic phase:The diastolic phase:►► Isovolumic relaxation (RIVRT);Isovolumic relaxation (RIVRT);►► Rapid filling period characterized by aRapid filling period characterized by anegative wave (E’)negative wave (E’)►► diastasisdiastasis►► filling due to atrial contraction, a secondfilling due to atrial contraction, a secondnegative wave (A’)negative wave (A’)
    16. 16. Pulsed-wave TDIPulsed-wave TDI• Multiple myocardial segments cannotMultiple myocardial segments cannotanalyzed simultaneouslyanalyzed simultaneously
    17. 17. Color M-modeColor M-mode• Anatomical M-Mode means a line whichAnatomical M-Mode means a line whichcan be placed anywhere and in anycan be placed anywhere and in anydirection in the imagedirection in the image• Curved M-Mode line is not even just aCurved M-Mode line is not even just astraight line, but can be drawn by hand,straight line, but can be drawn by hand,e.g. along the curvature of the ventriculare.g. along the curvature of the ventricularmyocardium, and then be moved in ordermyocardium, and then be moved in orderto follow the myocardial motionto follow the myocardial motion
    18. 18. Curved M-ModeCurved M-Mode
    19. 19. Anatomical M-ModeAnatomical M-Mode
    20. 20. M-ModeM-Mode• Various length of myocardium can beVarious length of myocardium can beanalyzedanalyzed• Wall movement is depicted color codedWall movement is depicted color coded• Spatial informationSpatial information →→ y axisy axis• Temporal informationTemporal information →→ x-axisx-axis• Myocardial velocity gradients between epi-Myocardial velocity gradients between epi-and endocardium may be obtained withand endocardium may be obtained withhighest velocity at endocardiumhighest velocity at endocardium
    21. 21. During systole basal and mid segmentsDuring systole basal and mid segmentsmove inwards & longitudinally towards amove inwards & longitudinally towards acenter of gravitycenter of gravity• Centre of gravity of heart located betweenCentre of gravity of heart located betweenthe second and third part of the long axisthe second and third part of the long axis• Contraction of subendocardial longitudinalContraction of subendocardial longitudinalfibers can be reliably assessed by TDIfibers can be reliably assessed by TDIfrom the apical viewsfrom the apical views
    22. 22. Applications of TDIApplications of TDI• Global and regional left ventricular systolicGlobal and regional left ventricular systolicfunctionfunction• Left ventricular diastolic functionLeft ventricular diastolic function• Left ventricular filling pressuresLeft ventricular filling pressures• LV dyssynchrony for CRTLV dyssynchrony for CRT• Distinction of different cardiac diseasesDistinction of different cardiac diseases
    23. 23. During ischaemiaDuring ischaemia• Longitudinal endocardial fibers areLongitudinal endocardial fibers areprimarily affectedprimarily affected• Peak systolic velocities reducedPeak systolic velocities reduced• Reversal of isovolemic relaxation velocityReversal of isovolemic relaxation velocity• Reduction of early and late diastolicReduction of early and late diastolicvelocitiesvelocities
    24. 24. Longitudinal velocity profiles areLongitudinal velocity profiles aresimilar in all wall segmentssimilar in all wall segments
    25. 25. Stress echocardiographyStress echocardiography• Katz et al. found significantly lower systolicKatz et al. found significantly lower systolicvelocities at peak stress in abnormal segmentsvelocities at peak stress in abnormal segments(3.1 ± 1.2 cm/s vs. 7.2 ± 1.9 cm/s)(3.1 ± 1.2 cm/s vs. 7.2 ± 1.9 cm/s)• In apical abnormal segments the velocityIn apical abnormal segments the velocityresponse could not be distinguished from normalresponse could not be distinguished from normal• A peak stress velocity response of ≤ 5.5 cm/sA peak stress velocity response of ≤ 5.5 cm/smay be useful in identifying abnormal segmentsmay be useful in identifying abnormal segmentsin all except apical segmentsin all except apical segments
    26. 26. Markers of ischaemiaMarkers of ischaemia►►Reduced rise in systolic velocityReduced rise in systolic velocity►►An altered motion pattern during IVRTAn altered motion pattern during IVRT►►An inverted E:A ratioAn inverted E:A ratio• Reduction in Sa velocity can be detectedReduction in Sa velocity can be detectedwithin 15 seconds of the onset of ischemiawithin 15 seconds of the onset of ischemia• Regional reductions in Sa are correlatedRegional reductions in Sa are correlatedwith regional wall motion abnormalitieswith regional wall motion abnormalities
    27. 27. Global Systolic FunctionGlobal Systolic Function• Measurement of longitudinal shortening ofMeasurement of longitudinal shortening ofthe left ventriclethe left ventricle• This is reflected in mitral annular descentThis is reflected in mitral annular descent• A six-site peak mitral annular descentA six-site peak mitral annular descentvelocity of >5.4 cm/s identified LVEFvelocity of >5.4 cm/s identified LVEFwithin normal range with reasonablewithin normal range with reasonablesensitivity and specificitysensitivity and specificity
    28. 28. • Mitral annulus-TDI velocities areMitral annulus-TDI velocities aredependent on loading conditions, atrialdependent on loading conditions, atrialhaemodynamics and heart ratehaemodynamics and heart rate• At the lateral mitral annulus is a measureAt the lateral mitral annulus is a measureof longitudinal systolic function and isof longitudinal systolic function and iscorrelated with LV ejection fractioncorrelated with LV ejection fraction
    29. 29. Six Mitral Annular SitesSix Mitral Annular Sites
    30. 30. Diastolic FunctionDiastolic Function1) discriminate a normal from a1) discriminate a normal from apseudonormal filling patternpseudonormal filling pattern2) to estimate diastolic function in atrial2) to estimate diastolic function in atrialfibrillationfibrillation3) to differentiate restrictive3) to differentiate restrictivecardiomyopathy from constrictivecardiomyopathy from constrictivepericarditispericarditis
    31. 31. • Mitral inflow reflects global diastolic functionMitral inflow reflects global diastolic functionwhile TDI enables regional diastolic functionwhile TDI enables regional diastolic function• Areas of interestAreas of interest →→ Mitral annulus & BasalMitral annulus & Basalsegments in 4 and 2-chamber Apical viewsegments in 4 and 2-chamber Apical view• Since apex is relatively fixed throughout theSince apex is relatively fixed throughout thecardiac cyclecardiac cycle• Measured velocities are nearly entirely due toMeasured velocities are nearly entirely due tocontraction and relaxation of the cardiac basecontraction and relaxation of the cardiac base
    32. 32. • Global diastolic function can be expressedGlobal diastolic function can be expressedby averaging velocities in four segmentsby averaging velocities in four segments• Normal early (E’) diastolic velocity range isNormal early (E’) diastolic velocity range is> 10 cm/s in the young and > 8 cm/s in> 10 cm/s in the young and > 8 cm/s inthe older patientthe older patient• Late diastolic velocities (A’) increase withLate diastolic velocities (A’) increase withageage
    33. 33. • Mitral inflow E wave decreases in the earlyMitral inflow E wave decreases in the earlystages of diastolic dysfunction --delayedstages of diastolic dysfunction --delayedrelaxationrelaxation• Increases again in the more advancedIncreases again in the more advancedpseudonormal phasepseudonormal phase• Both phases lead to a reduction of E’ to <Both phases lead to a reduction of E’ to <8 cm/s, decreasing more in the restrictive8 cm/s, decreasing more in the restrictivephasephase
    34. 34. • Mitral inflow patterns are highly sensitiveMitral inflow patterns are highly sensitiveto preloadto preload• TDI assessment of diastolic function isTDI assessment of diastolic function isless load dependentless load dependent• Septal Ea velocities are slightly lower thanSeptal Ea velocities are slightly lower thanlateral Ea velocities because of intrinsiclateral Ea velocities because of intrinsicdifferences in myocardial fiber orientationdifferences in myocardial fiber orientation
    35. 35. Estimation of LV fillingEstimation of LV fillingpressurespressuresMeasure transmitral early rapid diastolicMeasure transmitral early rapid diastolicfilling (E) by PW conventional dopplerfilling (E) by PW conventional doppler• measures Ea by pulsed-TDE samplemeasures Ea by pulsed-TDE samplevolume placed in the lateral annulusvolume placed in the lateral annulus• An E/Ea >10 is predictive of a meanAn E/Ea >10 is predictive of a meanpulmonary capillary wedge pressurepulmonary capillary wedge pressureabove 15 mmHg with a sensitivity andabove 15 mmHg with a sensitivity andspecificity of 92 and 80 percentspecificity of 92 and 80 percent
    36. 36. For Medial AnnulusFor Medial Annulus• Patients with E/E’ >15 can be classified asPatients with E/E’ >15 can be classified ashaving elevated filling pressurehaving elevated filling pressure• An E/E’ < 8 suggests normal fillingAn E/E’ < 8 suggests normal fillingpressurepressure• In the range of E/E’ of 8 to 15, otherIn the range of E/E’ of 8 to 15, otherinformation neededinformation needed
    37. 37. E/Ea RatioE/Ea Ratio• Early diastolic velocity at the mitralEarly diastolic velocity at the mitralannulus (Ea) reflect LV relaxation and isannulus (Ea) reflect LV relaxation and isless influenced by left atrial pressureless influenced by left atrial pressure• The ratio E/Ea can correct for theThe ratio E/Ea can correct for theinfluence of relaxation on transmitral Einfluence of relaxation on transmitral Eand relates strongly to filling pressuresand relates strongly to filling pressures• Lateral annular velocities are higher andLateral annular velocities are higher andeasier to record than the septal velocitieseasier to record than the septal velocities
    38. 38. Mitral inflow to annular ratioMitral inflow to annular ratio
    39. 39. Diastology investigatorsDiastology investigators• IVRT / T E-Ea < 2 found to have aIVRT / T E-Ea < 2 found to have asensitivity of 91% and a specificity of 89%sensitivity of 91% and a specificity of 89%for detecting PCWP >15 mm Hgfor detecting PCWP >15 mm Hg• 2 for patients with sinus rhythm without2 for patients with sinus rhythm withoutmitral valve diseasemitral valve disease• 3 for patients with mitral regurgitation3 for patients with mitral regurgitation• 4.16 for patients with mitral stenosis4.16 for patients with mitral stenosis• 5.59 for patients with atrial fibrillation5.59 for patients with atrial fibrillation
    40. 40. constrictive pericarditisconstrictive pericarditisVersus restrictiveVersus restrictivecardiomyopathycardiomyopathy• General guidelines -- Ea less than 10 cm/sGeneral guidelines -- Ea less than 10 cm/sby pulsed-TDE and less than 7 cm/s byby pulsed-TDE and less than 7 cm/s bycolor-coded TDE are supportive ofcolor-coded TDE are supportive ofrestrictive pathophysiologyrestrictive pathophysiology• In a series of 75 patients, an E of moreIn a series of 75 patients, an E of morethan 8 cm/s had a 95 percent sensitivitythan 8 cm/s had a 95 percent sensitivityand 96 percent specificity for the diagnosisand 96 percent specificity for the diagnosisof constrictive pericarditisof constrictive pericarditis
    41. 41. HypertrophicHypertrophicCardiomyopathyCardiomyopathy• Significantly reduced peak velocities in theSignificantly reduced peak velocities in thehypertrophied septum and the posteriorhypertrophied septum and the posteriorwallwall• In the septum, transmural velocity profilesIn the septum, transmural velocity profilesare also less uniform than in the posteriorare also less uniform than in the posteriorwall, possibly reflecting the degree ofwall, possibly reflecting the degree ofmyocardial disarraymyocardial disarray
    42. 42. Early diagnosis ofEarly diagnosis ofhypertrophic cardiomyopathyhypertrophic cardiomyopathy• Myocardial contraction and relaxation velocitiesMyocardial contraction and relaxation velocitiessignificantly reduced in those with an overtsignificantly reduced in those with an overthypertrophic cardiomyopathy and those with ahypertrophic cardiomyopathy and those with amutation compared to controlsmutation compared to controls• The sensitivity and specificity of TDE forThe sensitivity and specificity of TDE foridentifying patients with a mutation who did notidentifying patients with a mutation who did nothave left ventricular hypertrophy was 100 and 93have left ventricular hypertrophy was 100 and 93percent, respectivelypercent, respectively(Tissue Doppler imaging consistently detects myocardial abnormalities in patients with(Tissue Doppler imaging consistently detects myocardial abnormalities in patients withhypertrophic cardiomyopathy and provides a novel means for an early diagnosis before andhypertrophic cardiomyopathy and provides a novel means for an early diagnosis before andindependently of hypertrophy. Circulation 2001; 104:128.)independently of hypertrophy. Circulation 2001; 104:128.)
    43. 43. TDI Technique For AsynchronicityTDI Technique For Asynchronicity• Pulsed-wave TDIPulsed-wave TDI• Color-coded TDIColor-coded TDI• Tissue trackingTissue tracking• Displacement mappingDisplacement mapping• Strain and strain rate imagingStrain and strain rate imaging• Tissue synchronization imaging (TSI)Tissue synchronization imaging (TSI)
    44. 44. • Søgaard et al. focuses on late- or post-Søgaard et al. focuses on late- or post-systolic longitudinal motion towards thesystolic longitudinal motion towards thetransducer (“contraction”)transducer (“contraction”)
    45. 45. • Yu et al. looked at regional differencesYu et al. looked at regional differencesbetween the interval from QRS onset tobetween the interval from QRS onset topeak systolic velocitypeak systolic velocity
    46. 46. • Pulsed-wave TDIPulsed-wave TDI• Color-coded TDIColor-coded TDI• With pulsed-wave TDI, only one regionWith pulsed-wave TDI, only one regioncan be interrogated at a time--- time-can be interrogated at a time--- time-consuming and precludes comparison ofconsuming and precludes comparison ofsegments simultaneouslysegments simultaneously
    47. 47. Color coded TDIColor coded TDI• Velocity tracings derived from the basalVelocity tracings derived from the basalseptal and lateral segmentsseptal and lateral segments• Septal-to-lateral delay measuredSeptal-to-lateral delay measured• A delay 60 ms is predictive of acuteA delay 60 ms is predictive of acuteresponse to CRTresponse to CRT
    48. 48. LV DyssynchronyLV DyssynchronyTissue Velocity assessment for Septal-lateral delay (95ms)Tissue Velocity assessment for Septal-lateral delay (95ms)
    49. 49. Temporal inhomogeneities of myocardial motionTemporal inhomogeneities of myocardial motionare recognized at best by using the Curved M-are recognized at best by using the Curved M-Mode displayMode display
    50. 50. 6 Basal & 6 Mid segments6 Basal & 6 Mid segments• Yu et al used a 12-segment modelYu et al used a 12-segment model• Tracings derived from 12 segmentsTracings derived from 12 segments• LV dyssynchrony index derived from theLV dyssynchrony index derived from thestandard deviation of all 12 time intervalstandard deviation of all 12 time interval• Standard deviation of time-to-peak systolicStandard deviation of time-to-peak systolicvelocity Yu Index, > 33 ms also predictsvelocity Yu Index, > 33 ms also predictsclinical outcome and reverse remodelingclinical outcome and reverse remodelingfollowing CRTfollowing CRT
    51. 51. Tissue synchronization imagingTissue synchronization imaging• Signal-processing algorithm of the tissueSignal-processing algorithm of the tissueDoppler dataDoppler data• Detect peak positive velocityDetect peak positive velocity• Color-code the time to peak velocities inColor-code the time to peak velocities ingreen for normal timing, yellow-orange forgreen for normal timing, yellow-orange formoderate delay, and red for severe delaysmoderate delay, and red for severe delaysin peak longitudinal velocityin peak longitudinal velocity
    52. 52. ArrhythmiasArrhythmias• Frame rates of > 200 and temporal resolution ofFrame rates of > 200 and temporal resolution of5 ms can be achieved by reducing the sector5 ms can be achieved by reducing the sectorangleangle• TDI able to detect early contraction sitesTDI able to detect early contraction siteseffective for localizing left sided accessoryeffective for localizing left sided accessorypathway in particular in the anterior,pathway in particular in the anterior,anterolateral and inferior wallsanterolateral and inferior walls• Curved M-Mode is useful to investigateCurved M-Mode is useful to investigateconduction abnormalities such as bundle branchconduction abnormalities such as bundle branchblocks or pre-excitation syndromesblocks or pre-excitation syndromes
    53. 53. Right Ventricle FunctionRight Ventricle Function• Reduced tricuspid annular velocitiesReduced tricuspid annular velocitiesdemonstrated in Postinferior myocardialdemonstrated in Postinferior myocardialinfarction, chronic pulmonaryinfarction, chronic pulmonaryhypertension, and chronic heart failurehypertension, and chronic heart failure
    54. 54. LimitationsLimitations• For pulsed wave TDI inter observerFor pulsed wave TDI inter observerreproducibilities for peak systolic velocityreproducibilities for peak systolic velocityhave been reported from 4 % for thehave been reported from 4 % for thelateral annulus to 24 % for the short axislateral annulus to 24 % for the short axis• Reproducibility better in the long axis thanReproducibility better in the long axis thanin the short axis viewin the short axis view
    55. 55. • Minor changes in transducer positionMinor changes in transducer positionduring image acquisition can lead toduring image acquisition can lead tosignificant changessignificant changes• Sample volume position has to beSample volume position has to be“standardized” when comparison of“standardized” when comparison ofimages is requiredimages is required
    56. 56. • Whole cardiac motion and tetheringWhole cardiac motion and tetheringeffects in scar regions may limit accuracyeffects in scar regions may limit accuracyby substantial “false” velocity increase ofby substantial “false” velocity increase ofdysfunctional segmentdysfunctional segment
    57. 57. Strain Rate Imaging (SRI)Strain Rate Imaging (SRI)• Strain means tissue deformation due toStrain means tissue deformation due toapplied stressapplied stress• Elongation of the myocardium is positiveElongation of the myocardium is positivestrain whereas shortening is negativestrain whereas shortening is negativestrainstrain• S = ΔL / L0S = ΔL / L0• where S = strain, ΔL = change in lengthwhere S = strain, ΔL = change in lengthand L0 = basal lengthand L0 = basal length
    58. 58. • Strain rate (SR) measures the rate ofStrain rate (SR) measures the rate ofdeformation, which is equivalent to thedeformation, which is equivalent to theMVGMVG• Strain rate imaging has better spatialStrain rate imaging has better spatialresolutionresolution• Help to decide what is seen in wall motion,Help to decide what is seen in wall motion,whether there is true contractionwhether there is true contraction(deformation) or only motion (tethering)(deformation) or only motion (tethering)
    59. 59. ArtifactsArtifacts
    60. 60. Automated analysisAutomated analysis• Manual or automatic placement ofManual or automatic placement ofanatomical landmarks, such as the mitralanatomical landmarks, such as the mitralplane and the apex orplane and the apex or• Draw a curve along the myocardiumDraw a curve along the myocardium• Walls are then automatically segmentedWalls are then automatically segmented• Strain rate calculated according to theStrain rate calculated according to theapplication usedapplication used
    61. 61. • SRI is based on calculation of DopplerSRI is based on calculation of Dopplersignals and measures distances along thesignals and measures distances along theultrasound beam and not in tissueultrasound beam and not in tissue• Consecutively, angle dependent errorsConsecutively, angle dependent errorscan occur, leading to reduced or evencan occur, leading to reduced or eveninverted strain ratesinverted strain rates• segments with different elastic properties,segments with different elastic properties,and also different loading conditions canand also different loading conditions caninfluence SR valuesinfluence SR values
    62. 62. • Random noise frequently occurs,Random noise frequently occurs,rendering interpretation of strain raterendering interpretation of strain ratetracings difficulttracings difficult• Myocardial strain rate: dividing theMyocardial strain rate: dividing thelongitudinal TDI velocities by the distancelongitudinal TDI velocities by the distancefrom the point of measurement to the apexfrom the point of measurement to the apex
    63. 63. • TDI and StrainTDI and Strain• A. Tissue Doppler imaging from basal(yellow), mid(blue) and apical(red) segments of the ventricular septum in a patient withA. Tissue Doppler imaging from basal(yellow), mid(blue) and apical(red) segments of the ventricular septum in a patient withHypertrophic cardiomyopathy. Systolic (Ss) velocities for all three segments are decreased equally to 4cm/s. are markedlyHypertrophic cardiomyopathy. Systolic (Ss) velocities for all three segments are decreased equally to 4cm/s. are markedly• B. Strain recordings from the same 3 segments different.B. Strain recordings from the same 3 segments different.• Strain (arrows) was normal at the apex(red -30%) and decreased at the base(yellow -10%) and lengthened at the mid septumStrain (arrows) was normal at the apex(red -30%) and decreased at the base(yellow -10%) and lengthened at the mid septum(blue+5%)(blue+5%)
    64. 64. Assessment of Myocardial ViabilityAssessment of Myocardial Viability• MVG can be used to differentiate viable from nonviable myocardiumMVG can be used to differentiate viable from nonviable myocardiumin patients with acute MI treated with acute perfusion.in patients with acute MI treated with acute perfusion.• It has been observed that myocardial shortening occurs even afterIt has been observed that myocardial shortening occurs even afterAortic valve closure, called post systolic shortening. This maybe anAortic valve closure, called post systolic shortening. This maybe anindication of asynchronous motion during IVR period.indication of asynchronous motion during IVR period.• TDI and strain imaging are able to demonstrate this unusual cardiacTDI and strain imaging are able to demonstrate this unusual cardiacmotion.motion.• Post systolic shortening of stunned myocardium may disappearPost systolic shortening of stunned myocardium may disappearwith gradual infusion of Dobutamine.with gradual infusion of Dobutamine.• Presence of Post systolic shortening after acute myocardialPresence of Post systolic shortening after acute myocardialischaemia also predicts functional recovery after reperfusionischaemia also predicts functional recovery after reperfusiontherapy.therapy.
    65. 65. Strain Rate and Strain ImagingStrain Rate and Strain Imaging• Assessment ofAssessment ofMyocardial ViabilityMyocardial Viability• Strain rate A and strainStrain rate A and strainimaging B of a patient withimaging B of a patient withpost systolic shorteningpost systolic shortening(arrow)(arrow)• Post systolic shortening wasPost systolic shortening waspresent in the midpresent in the midseptum(aqua colour)septum(aqua colour)• AVC- Aortic valve closureAVC- Aortic valve closure• AVO- Aortic Valve OpeningAVO- Aortic Valve Opening
    66. 66. Calculation of the myocardialCalculation of the myocardialvelocity gradientvelocity gradient

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