alicia armour, ma, bs, rdcs - home - ncus · cardiac resynchronization therapy (crt) dyssynchrony...

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’-lo)/lo = Δl/lo (dimensionless)

l’ and lo 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) timing-opening & 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?

EKG

AVC

Waveforms trace the regional strain throughout the cardiac cycle

GS = -13.9%

Regional systolic strains

Global Peak Strain for each view (an average) Overall Global L. Peak Strain (another average)

Peak Systolic Strain for each region

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

Colors represent the movement of the speckles throughout the cardiac cycle

AVC

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


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)


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.


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.


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.


Cardiomyopathies (in general)

Hypertrophic Cardiomyopathies (HCM)

Athlete’s Heart

Sarcoidosis, Lupus

Amyloidosis

Myocardial Infarction

And the list can go on…

alicia armour, ma, bs, rdcs - home - ncus · cardiac resynchronization therapy (crt) dyssynchrony...

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