Alicia Armour, MA, BS, RDCS
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Review 2D Speckle Strain (briefly) Discuss some various patient populations & disease pathways where Strain can be helpful Discuss how to acquire images for Strain analysis
Deformation dealing with shape and volume change Distance between some particles changes Angle between particle lines may change Longitudinal Strain: shortening or lengthening; e: change in length per length e=(l -l o )/l o = Δl/l o (dimensionless) l and l o are the final and original lengths of a linear object Shortening is a negative extension (e<0)
2D Speckle Tracking (our focus today) Myocardial deformation (fractional change in length of a myocardial segment) Unitless, expressed as a percentage Positive (lengthening) or negative (shortening) values Current and Evolving Echocardiographic Techniques for the Quantitative Evaluation of Cardiac Mechanics: ASE/EAE Consensus Statement on Methodology and Indications Mor-Avi et al., JASE 2011; 24:277-313
What images are required What spectral Doppler information is required How they need to be optimized How to analyze
2D Images Required: SAX from the apex, mid-level (paps) and mitral valve (for radial strain as applicable) Apical 4 chamber Apical 2 chamber Apical Long Doppler images Required (for AoV closure timing): CW through AoV PW of LVOT
Not all patients have studio quality images, and it still tracks!!!
Most programs require a frame rate of 60-90Hz How to optimize that image: LV focus Less depth Narrow sector arc Images need speckle to track, so focus on endocardial border definition
Need images to be acquired within 5 beats for consistency Breath hold/same time in respiration Acquire 3 beat loops Some systems need 100ms before & after each cardiac cycle for analysis Acquiring 3 beat loops gives you more options for analysis afterwards & can overcome pre/post cycle timing issues
Most systems require aortic valve (AoV) timingopening & closing CW through AoV PW the LVOT Some systems require R to R timing as well (any spectral Doppler image will work). If you want to include mitral timing-pw MV inflow
Measure on the valve clicks (for CW or PW as applicable)
Can override spectral Doppler timing in most systems Can use 2D image but Our lab has found more variance in timing & less accuracy with using the 2D images If you use persistence or smoothing you 2D image may also provide inaccurate data
Find the best Apical 4, 2 & long axis images Find your spectral Doppler image for tracing Set AoV timing information Use analysis system image by image Some systems require the following sequence: Apical Long, Apical 4ch, Apical 2Ch
Average Global Peak Longitudinal Strain: -6.7% (abnormal)
Ensure the tracking! Is the tracking moving with the endocardium? Change the way you look at the image-watch the longitudinal movement Are there any ballistic movements through the tracking? Watch the base!
Check the waveforms! Do they make sense? What do they mean? What are the other things shown in the analysis?
What do the waveforms show? What are they similar to?
AVC Waveforms trace the regional strain throughout the cardiac cycle EKG
GS = -13.9% Regional systolic strains
Peak Systolic Strain for each region Global Peak Strain for each view (an average) Overall Global L. Peak Strain (another average)
Red = speckles moving toward each other longitudinally Deep red = more negative strain Blue = speckles moving away from each other longitudinally White = little to no movement
AVC Colors represent the movement of the speckles throughout the cardiac cycle
Most systems produce a Bullseye The numbers displayed are the peak longitudinal strain before AoV closure All peak strains for each view & the Global Strain are averages (of averages )
Average Global Longitudinal Peak Strain (GLPS_Avg): -16.7% Peak Systolic Strain for each region prior to AVC
Images required: Apical Long, 4ch, 2ch Frame Rate of 60-90Hz LV focused view (less depth) with narrow sector arc 3 beat loops with a breath hold (same point in respiration each time) Heart Rate within 5 beats CW of AoV or PW of LVOT
Measure AoV timing Follow software for sequence & setting points
Advantages: Analysis can be performed in any direction within the imaging plane Depending on spatial resolution epicardial, midwall & endocardial function may be analyzed as well Semiautomatic LV segment definition shows well in most patients making it possible to analyze in most patients successfully Current and Evolving Echocardiographic Techniques for the Quantitative Evaluation of Cardiac Mechanics: ASE/EAE Consensus Statement on Methodology and Indications Mor-Avi et al., JASE 2011; 24:277-313
Disadvantages: Image quality dependent Acoustic shadowing or reverberations may cause underestimation of true deformation Difference among vendors Tracking algorithms use spatial smoothing & prior knowledge of normal LV function (erroneous regional dysfunction) Relies on assumption that morphologic details can be tracked in consecutive frames, which may not be true when out of plane motion occurs (requiring high temporal resolution) Current and Evolving Echocardiographic Techniques for the Quantitative Evaluation of Cardiac Mechanics: ASE/EAE Consensus Statement on Methodology and Indications Mor-Avi et al., JASE 2011; 24:277-313
Myocardial Mechanics Cardiac Resynchronization Therapy (CRT) Dyssynchrony Activation-delay induced cardiomyopathy
Overall goal: to get the walls to all contract at the same time Still need required Doppler information (MV inflow, PW of LVOT) used for Stroke Volume & Cardiac Output Depending on how your lab works: Time to Peak Waveforms
We use the waveforms, specifically observing regional patterns. Overall GLPS is also used in conjunction with Doppler information & 3D LVEF
61 year old female Heart Failure (non-ischemic cardiomyopathy), NYHA class II-III symptoms BiV/ICD in 2006 (lateral lead placement) AVR & MV repair 2002 Diabetes, hyperlipidemia, hypothyroidism, COPD, obstructive sleep apnea (OSA), chronic kidney disease (CKD)
Global Longitudinal Peak Strain Average -7.8%
Average VTI 19 cm
Tried various settings for sensed AV delay (SAV) and LV offset/pre-activation using VTI as improvement parameter End settings: SAV delay 120 ms VTI 25 cm (from 19 cm at baseline) LV pre-excitation -30 ms VTI 30.5 cm (from 19 cm at baseline) GLPS post-optimization -10.3% vs. -7.8% at baseline
LV-30 Average VTI 31 cm (final setting) Baseline Average VTI 19 cm
Baseline Bulls eye Final Settings Bulls eye Average GLPS -7.8% Average GLPS -10.3%
Post MI, is myocardium still viable? What other echo parameters can detect rejection? Are there any other useful echo tools for serial evaluation of cancer treatment patients that detect cardiotoxicity early? Besides LVEF & LV dimensions, how can I tell an athlete s heart from HCM or a hypertrophied heart? Regional changes in HCM patients-can this be tracked by echo as well as MRI? Can strain help detect LV dysfunction early with valvular disease?
Strain analysis increases sensitivity in detecting subclinical cardiac involvement in diseases such as: amyloidosis, diabetes and hypertensive heart disease. It will also show change in LV function after cancer treatment. Current and Evolving Echocardiographic Techniques for the Quantitative Evaluation of Cardiac Mechanics: ASE/EAE Consensus Statement on Methodology and Indications Mor-Avi et al., JASE 2011; 24:277-313
Cancer treatment patients Coronary Artery Disease Valvular Disease
Cardiotoxicity after anthracycline (ANT) therapy can be as high as 18-26%; upwards of 36%. Heart failure can occur up to 20 years after successful treatment. 1 Several clinical trials have shown that while ejection fraction (EF) and fractional shortening remain normal, early signs of cardiotoxicity can be seen in Doppler and Strain parameters. 2 1. Editorial Comment: Identification of Anthracycline Cardiotoxicity: Left Ventricular Ejection Fraction Is Not Enough, Eidem, B W, MD, JASE 2008. 2. Strain Rate Imaging Detects Early Cardiac Effects of Pegylated Liposomal Doxorubicin as Adjuvant Therapy in Elderly Patients with Breast Cancer, Jurcut et al., JASE 2008;21:1283-1289.
One research study in adolescents showed changes at 4 & 8 months in Longitudinal Peak Systolic Strain (LPSS) (ANT group averaged 18.1% vs. Control at 20.5%.) Impaired/decreased areas were observed for basal and mid averages. 3. Changes in Left Ventricular Longitudinal Strain with Anthracycline Chemotherapy in Adolescents Precede Subsequent Decreased Left Ventricular Ejection Fraction, Poterucha, Joseph et al., JASE 2012; 25:733-40
From Changes in LV Longitudinal Strain with Anthracycline, Poterucha et al., JASE 2012; 25:733-40
LPSS detected changes earlier than changes in LVEF (visual and calculated). Doppler parameters also indicated changes in the ANT group earlier than LVEF changes. 2D Speckle-Tracking LV LPSS can be useful in serial clinical monitoring for ANT cardiotoxicity. From Changes in Left Ventricular Longitudinal Strain with Anthracycline Chemotherapy in Adolescents Precede Subsequent Decreased Left Ventricular Ejection Fraction, Poterucha et al., JASE 2012; 25:733-40
Subendocardium most vulnerable area LV longitudinal mechanics at rest may be attenuated in patients with CAD Recent research shows: Correlation between Doppler-derived strain rate and coronary stenosis (85% specificity & 64% sensitivity). STE LS can be indicative of CAD extent From Assessment of Myocardial Mechanics Using Speckle Tracking Echocardiography: Fundamentals and Clinical Applications, Geyer, H. et al., JASE 2010;23:351-69
Stress Echo: strain changes can be indicative of ischemic myocardium & provide diagnostic information Resting cardiac strain can help define transmural extent of myocardial infarction (MI) and presence of viable myocardium. From Assessment of Myocardial Mechanics Using Speckle Tracking Echocardiography: Fundamentals and Clinical Applications, Geyer, H. et al., JASE 2010;23:351-69
71 y.o. female Chest pain radiating to neck No prior history of CAD Sent to CDU for Stress Echo
Stress Echo 71 y.o. female (Target HR 126, Max HR 149bpm)
Stress Echo
LV Strain Study 71 y.o. female
LV Strain Study Report 71 y.o. female
Coronary Angiography 71 y.o. female
LV remodeling can occur with or without symptoms even in the setting of severe valvular disease Strain-Tracking Echocardiography (STE) detects remodeling/cardiac dysfunction improving the yield of 2D echocardiography in patients with valvular diseases. Assessment of Myocardial Mechanics Using Speckle Tracking Echocardiography: Fundamentals and Clinical Applications, Geyer, H. et al., JASE 2010;23:351-69
LVH (with preserved LVEF) due to increased afterload Speckle-tracking longitudinal strain is impaired (or reduced ) with severe AS; while radial & circumferential strains remain relatively preserved. Post aortic valve replacement (AVR), all 3 forms of strain show improvement. Assessment of Myocardial Mechanics Using Speckle Tracking Echocardiography: Fundamentals and Clinical Applications, Geyer, H. et al., JASE 2010;23:351-69
68yo male with history of non-ischemic cardiomyopathy & valvular disease Seen initially to evaluate valvular disease & dyssynchrony
Not a significant improvement in LV function but patient reports feeling better. Small improvements in Global LS as well as regional strains. Increase in mean AoV gradient (from 25mmHg to 42mmHg)
Aortic Insufficiency (AI): Increase in LV end-diastolic volume & preload Remodeling to compensate which can mask onset of LV dysfunction DTI-derived strain (& strain rate): longitudinal & radial peak systolic strain correlate with LV ESV & EDV STE global longitudinal strain (LS) is reduced/impaired in patients with AI & bicuspid aortic valves. STE global radial strain shows changes immediately post AVR, but after 6mo follow up shows improvement. Assessment of Myocardial Mechanics Using Speckle Tracking Echocardiography: Fundamentals and Clinical Applications, Geyer, H. et al., JASE 2010;23:351-69
Mitral Regurgitation DTI-derived strain: longitudinal & radial strain reduced/impaired with severe MR & directly related to LV stroke volume (SV), diameter & contractility. STE-derived LS reported impaired with severe MR earlier than circumferential & radial strain. LV twist mechanics are reported to remain preserved. Assessment of Myocardial Mechanics Using Speckle Tracking Echocardiography: Fundamentals and Clinical Applications, Geyer, H. et al., JASE 2010;23:351-69
Cardiomyopathies (in general) Hypertrophic Cardiomyopathies (HCM) Athlete s Heart Sarcoidosis, Lupus Amyloidosis Myocardial Infarction And the list can go on