How To Perform Strain Imaging; Step By Step Approach. Maryam Bo Khamseen Echotechnoligist II EACVI, ARDMS, RCS King Abdulaziz Cardiac Center- Riyadh

Transcription

1 How To Perform Strain Imaging; Step By Step Approach Maryam Bo Khamseen Echotechnoligist II EACVI, ARDMS, RCS King Abdulaziz Cardiac Center- Riyadh

2 Outlines: Introduction Describe the basic of myocardium architecture Basic term and definition for myocardium function Explain the three principle of vectors myocardium deformation Clinical applications of STE for assessment of LV deformation Take home message

3 Introduction: The interpretation of wall motion is an important component of echocardiography but remain a source of variation between the observers An accurate and reproducible measurement of left ventricle is available by automated LV quantification

4 Cardiac Architecture -Historical Description Two layer of muscle fibers which travel in opposite direction Richard Lower. Tractatut de corde London 1969

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6 Clockwise rotation (-) Twist & Untwist (Due to helical structure of the heart) Counter-clockwise rotation (+)

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8 Terms and definition: basic parameters of myocardium function Speckle Tracking echocardiography(ste): Has emerge as an alternative angle independent technique based on frame-by-frame tracking of tiny echo dense speckle within myocardium and subsequent measure of LV deformation

9 Strain(s): describe myocardium deformation that is, the fractional change in the length of myocardium segment. Strain can be positive or negative which reflect lengthening or shortening respectively Strain Rate(SR): is the rate of change of strain and express as 1/sec or sec-1

10 LV Rotation: refers to myocardial rotation around the long axis of the LV.It is rotational displacement and is expressed in degree or radians. Normally the base and the apex of the ventricle will rotate in opposite direction. Net LV Twist: (express in degree or radians) Referred to an absolute apex-to-base different in LV rotation (Normally=20 degree)

11 Strain: + 20% -20 % 0 % 10 cm 8 cm 12 cm 10 cm Strain is unit less and expressed as %

12 Strain Rate: SR=1/4=.25 sec SR=1/2=.5 sec 1/sec or sec-1

13 JASE, January 2015

14 ASE/EACVI cardiac chamber quantification, 2015

15 The mechanics of the heart

16 1- Longitudinal contraction:

17 Shortening negative Lengthening positive End-systole

18 Positive strain lengthening Negative strain Shortening

19 Shortening Lengthening

20 2-Circumferential contraction:

21 3- Radial contraction:

22 The Heart Has a Rotation: Winging of a linen cloth to squeeze out the water

23 Rotation: The basal LV clockwise rotation N=-7) Apical LV counter-clockwise rotation (N =13)

24 Net LV Twist : Base Apex -9 Degree 19 Degree (0) -9 degrees 19 degrees (0) Net LV twist angle = +28 degrees (Normal=20 degrees)

25 Base Apex

26 4-year-old healthy boy (0) (0) Basal rotation= + 3 degree Apical rotation= + 6 degrees

27 25 years old male (0) (0) Basal rotation= -7% Apical rotation= +10%

28 Clinical applications of STE for assessment of left ventricular deformation STE in early detection of cardiotoxicity during and after chemotherapy STE in amyloidosis STE in HOCM STE in Aortic stenosis

29 A 10% to 15% early reduction in GLS by STE appears to be the most useful parameter for the prediction of cardiotoxicity.

30 Conclusion : AFI Obtained global longitudinal strain has better correlation with Auto EF than Simpson's method EACVI, Istanbul, 2013

31 Case 1 53-year-old female with breast cancer on chemotherapy(herceptin)

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33 Longitudinal Strain

34 Longitudinal Strain

35 Longitudinal Strain

36 Bull s eye

37 EF=54% Auto EF

38 F/U study one year later

39 Follow up after one year Baseline echo One year after chemotherapy GS= -20.3% GS= -14%

40 Follow up after one year Baseline echo One year after chemotherapy GS= -18% GS= -16.7%

41 Follow up after one year Baseline echo One year after chemotherapy GS= -19.2% GS= -13.7%

42 Follow up after one year Baseline echo One year after chemotherapy Reduce by 25% GLS_Avg= -19.3% GLS_Avg= -14.8%

43 STE in early detection of cardiotoxicity during and after chemotherapy STE in restrictive cardiomyopathy ( amyloidosis) STE in Aortic stenosis STE in HOCM

44 Case 2 82-year-old man presented to our center due to severe SOB and atrial fibrillation. No history of hypertension.

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51 Longitudinal Strain

52 -5-4

53 Longitudinal Strain

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56 Bullꞌs eye Cherry on top of the cake!!

57 STE in early detection of cardiotoxicity during and after chemotherapy STE in amyloidosis STE in Aortic stenosis STE in HOCM

58 Case 3 51-year-old male presented with SOB

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63 Basal LV

64 Circumferential Strain

65 Global Rotation Basal LV, clockwise rotation -7 Degree

66 Mid LV

67 Circumferential Strain

68 Apical LV

69 Circumferential Strain

70 Global Rotation Apical counterclockwise rotation + 25 degree Net LV twist =23 degree

71 -32% -39% -21% Circumferential Strain and LV twist are preserved

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73 Longitudinal Strain

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75 Longitudinal Strain

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77 Longitudinal Strain

78 Bulls eye Longitudinal Strain reduce

79 Conclusion: Following AVR significant improvement in LV myocardial strain both longitudinal and circumferential

80 Longitudinal Strain: Before AVR 6 Months later

81 Circumferential Strain: Before AVR 6 Months later

82 Case 4 67-year-old male with symptomatic HOCM

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84 Circumferential Strain

85 Circumferential Strain

86 Longitudinal Strain

87 Longitudinal Strain

88 Take Home Message: Echocardiography measures of LV strain by speckle tracking (STE) have become a robust method to measure myocardial deformation Resolving the multidirectional components of LV deformation, offers important insights for detecting subclinical states that are likely to progress into either systolic or diastolic heart failure. As STE became widely available, it will be an important mission to ensure standardization of nomenclature, steps in data acquisition, and optimal training to reduce data variability.

89 Thank You