Download Strain

GLS in clinical practice
Dr. Tanja Anguseva
Special Hospital for Surgery Fillip Vtori
31.03.2017, Skopje
What is strain??
<physics> the magnitude of a deformation, equal to
the change in the dimension of a deformed object
divided by it original dimension.
Initial length
L0
Start
Strain = (L-L0) / L0
(L – L0)
The change after
deformation
End
L
Strain = A measure of “deformation”
 Echocardiographic strain and strain rate imaging is a
new technology enabling more reliable and
comprehensive assessment of myocardial function
 Wide spectrum of clinical applications
- differentiate between active and passive movement
- quantify intraventricular dyssynchrony
- evaluate components of myocardial function- (longitudinal
myocardial shortening)
- early detection of myocardial disfunction of different ethyologies
- assessment of myocardial viability,
- detection of acute allograft rejection after heart transplantation
- early detection of patients with transplant coronary artery
disease,
- helpful in the selection of different therapies
- follow-up evaluations of myocardial function after different
medical and surgical treatment.
- Strain and strain rate data also provide important prognostic
information.
Normal values of longitudinal LV deformation are between -20 to -25 %.
Normal values of longitudinal function are still not confirmed in large population studies.
The following values could reflect the lower limits of longitudinal LV and RV function:
MAPSE (mitral annular plane systolic excursion)
MASV (mitral annular systolic velocity)
10 cm/s
LV-LSS (left venticular longitudinal systolic strain)
TAPSE (tricuspid annular plane systolic excursion)
TASV (tricuspid annular systolic velocity)
1 cm
– 20 %
2 cm
20 cm/s
RV-LSS (right ventricular longiudinal systolic strain)
– 30 %
Normal annular velocities, strain rate and strain per wall in the HUNT study.
1266 healthy individuals.
Anteroseptal
Anterior
(Antero)lateral
PwTDI S'
(cm/s)
8.3 (1.9)
cTDI S'
(cm/s)
-1
Inferolateral
Inferior
(Infero)septal
8.8 (1.8)
8.6 (1.4)
8.0 (1.2)
6.5 (1.4)
7.0 (1.8)
6.9 (1.4)
6.3 (1.2)
SR (s )
-0.99 (0.27)
-1.02 (0.28)
-1.05 (0.28)
-1.07 (0.27)
-1.03 (0.26)
-1.01 (0.25)
Strain (%)
-16.0 (4.1)
-16.8 (4.3)
-16.6 (4.1)
-16.5 (4.1)
-17.0 (4.0)
-16.8 (4.0)
Distribution of right ventricular strain for patient with and without pulmonary hypertension.
Nowell M. Fine et al. Circ Cardiovasc Imaging. 2013;6:711721
Copyright © American Heart Association, Inc. All rights reserved.
Four components of deformation
indices
Velocity
Displacement
Strain rate
Strain
The ESC textbook of cardiovascular medicine. Oxford University Press; 2009. 99–147.
Relationship among the 4 components
spatial Integral
[
d ]
spatial Integral
[ εd ]
spatial derivative
[dD/dx]
Strain
[no unit]
time derivative
[dD/dt]
time derivative
[dε/dt]
Displacement
[mm]
spatial derivative
[dV/dx]
Strain Rate [1/s]
(Velocity Gradient)
time Integral
[
dt]
time Integral
[  V dt ]
Velocity
[mm/s]
dt : time
dx : distance
Two types of myocardial strain
Tissue Doppler and Speckle
Tissue Doppler imaging
Very high frame rate, more than 100 frames per second.
However, one of the main draw backs of this technique is
the angle dependency because we use Doppler here.
Speckle tracking imaging
Methods
Doppler tissue imaging
• Two discrete points are compared for change in velocity
• Strain rate- primary parameter obtained
• Strain –derived by integrating velocity over time.
Speckle tracking
• Actual location of discrete myocardial segments
calculated.
• Strain is the primary parameter.
• Strain rate-derived by calculating change in distance over
time.
Three main
directions of strain
Circumferentiall
Radial
Longitu
dinal
Negative strain- shortening of segment.
Positive strain- lengthening of segment
Circumferential
Ejection Fraction
Radial
Longitudinal
Types of strain
Strain value
Longitudinal
Negative
(=shortening)
Circumferential
Negative
(=shortening)
Radial
Positive
(=thickening)
2) HOW TO MEASURE?
Example –EchoPAC PC
Steps 1-4
2) Click “Q-Analysis”
4) Select view
3) Click “2D Strain”
1) Choose an image
(First, APLAX[3CV], followed by 4CV and 2CV.)
Steps 5-7
5) Trace the endocardial border
and finish with double-click
6) Adjust the ROI width
(not to include the pericardium)
7) If you are happy with the tracking
quality, click “Approve”
Steps 5-7
8) Choose Aortic Valve closure timing
9) Click “Manual’, if you change
using your mouse
the timing.
10) Now, you’ve got strain curves from 3CV.
Continue these steps on 4CV and 2CV (except
for AVC timing).
Global longitudinal strain (GLS)
3CV
4CV
2CV
GLS -23.7%
3) CLINICAL IMPLICATION
NORMAL STRAIN -SYSTOLA
Normal strain: values of
myo cardial deformation at
systole lie here around -25 %
on the lateral segments of
the left ventricle. Color
encoded dynamic bidimensional image helps to
visualize strain, red stands
here for -20 %.
Normal Strain Displays
Wave Forms ,Curved M-mode
Normal Strain Displays- bulls eye
presentation
Normal pattern
Dilated cardiomyopathy
Dyssynchrony
Example cases
Baseline
F/U 1
BB: beta-blocker
F/U 2
More than 11%
drop in GLS
No BB
GLS -20.1%
EF 61%
GLS -17.0% (Δ15.4%)
EF 55%
GLS -21.9%
EF 62%
GLS -16.6% (Δ24%)
EF 51%
GLS -16.1%
EF 49%
More than 11%
drop in GLS
BB therapy
GLS -20.2%
EF 58%
Negishi et al. EHJ-CVI 2013
Aortic stenosis and myocardial hypertrophy
Aortic stenosis and myocardial ischemia
CAD- Myocardial ischemia, Myocardial
infarction, Myocardial viability
• Reduction in strain by 2D STE more objective and
accurate than the traditional visual method of
assessing WMA.
• Post systolic thickening (deformation)by radial strain
correlates with the severity of ischemia.
• To differentiate transmural from subendocardial
infarction- lower circumferential strain in the former
Applications
• Heart failure with normal LVEF
Reduced and delayed LV untwisting—at rest and
exercise
• Cardiac resynchronization therapy (CRT)
Speckle Tracking and Resynchronization (STAR) study
showed radial and transversal strain better than longitudinal
and circumferential strain in predicting LVEF response and
long term survival after CRT.
Lack of dyssynchrony before CRT by 2D STE radial
strain associated with death or hospitalization for heart failure
Twist in DCM
Am J Cardiol 2008;101:1163–
1169, 2008
Applications
• Stress cardiomyopathy.
• Restrictive cardiomyopathy.
• Detection of subclinical diseases/early myocardial
involvement.
• Detection of rejection and coronary stenosis in heart
transplant patients.
• Early detection of chemotherapy induced cardiotoxicity.
• Valvular heart diseaseDecreased radial, circumferential and longitudinal strain in
patients with severe aortic stenosis and normal LVEF. Long
term follow up after valve replacement showed significant
improvement in strain.
Differentiation of Athlete’s Heart from
Hypertrophic Cardiomyopathy
Athlete’s Heart
Hypertrophic
Cardiomyopathy
Normal longitudinal and other
types of strain
Decreased longitudinal strain
Increased LVEDV
Decreases after deconditioning for 3
months.
Decreased LVEDV
No change with deconditioning.
Increased LV twist.
Delayed LV untwisting.
Increased early LA strain rate.
Reduced LA strain and
strain rate
From: Cardiac imaging after myocardial infarction
Eur Heart J. 2010;32(3):272-283. doi:10.1093/eurheartj/ehq446
Figure Legend:
Determination of regional and global longitudinal strain. (A) End-diastolic and (B) end-systolic frame of patient after anteroapical myocardial infarction. Apical four-chamber view with semi-automatic calculation of regional longitudinal strain by speckletracking, which is colour-coded. (C) Bull's eye plot displaying regional longitudinal strain numerically and coded in colour. The
global (averaged) strain from all three apical standard views in this patient was −5.2%, indicating severely impaired global left
ventricular systolic function; normal values for global are above −14%, with a mean of −17% (33). ote bluish
anterior/anteroseptal akinesia/dyskinesia (positive numbers). (D) Regional longitudinal strain (y-axis) curves over time (x-axis);
the arrows indicate the left ventricular segments corresponding to the two representative strain curves. Yellow strain curve
corresponds to yellow dot, and blue strain curve to blue dot on the image in the left upper corner. The strain curve of the apical
septal segment (blue dot, blue curve) shows substantially reduced and delayed peak systolic longitudinal strain. AVC, time of
aortic valve closure.
Date of download: 3/29/2017
Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2010. For
permissions please email: [email protected].
Different Radial Strain Rate Patterns in Patients
with Similar LVEF (50%)
Ssr
Ssr
Strain rate 11 years after LVAD explantation „Off pump“ strain rate at time of max. improvement during BVAD support but incomplete
(pt. who has recovered from end- stage IDCM)
histological recovery from acute myocarditis.
Worsening of LVEF during further unloading
Systolic global peak strain rate (Ssr) = 2.8/s Systolic global peak strain rate (Ssr) = 1.33/s
Time Course of 2D Strain Images Recorded During
Reduction of LVAD (Incor) Rate in an IDCM Patient
Uniform Contraction and Higher Global Strain
Asynchrony and Dyssynergy
Circumferential
Strain
Radial
Strain
1 month
1 month
STRAIN - AMYLOIDOIDOSIS
Pathological strain:
values of myocardial
deformation at
systole lie here
around -7 %, being
consequently very
reduced. This case is
a proven myocardial
invol- vement in
systemic amyloidosis.
Strain can predict subsequent decrease in EF
in patients with chemotherapy.
Negishi et al. JASE 2013
Strain can guide cardio-protective therapy
in patients with chemotherapy.
BB (-)
EF(%)
75
75
Group A
p=0.27
between groups
Group T
p=0.09 between
groups
Group AT
65
65
55
55
F/U1 vs F/U2, p=0.06
Baseline
Group A
Group T
Group AT
45
BB (+)
EF(%)
F/U1
F/U2
F/U1 vs F/U2, p<0.001
45
Baseline
F/U1
F/U2
BB: beta-blocker F/U: follow-up
Negishi et al. EHJ-CVI 2013
5) Take home messages
Myocardial strain
• is not difficult and just a measure of
“deformation”.
• provides quantitative assessment of myocardial
deformation.
• is more sensitive and more robust than EF.
GLS in clinical practice
THANK YOU
Dr. Tanja Anguseva
Special Hospital for Surgery Fillip Vtori
31.03.2017, Skopje