Disclosures Contemporary Assessment of Cardiac I have nothing to - - PDF document

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Contemporary Assessment of Cardiac Function by Echocardiography Ann Bolger, MD William Watt Kerr Professor of Medicine

Disclosures

I have nothing to disclose

Systolic function in the echo lab: What is the question?

What is the EF? is the heart healthy? is the function normal? can the heart cope with what we need to do? Are there clues to a subclinical problem? Is EF the parameter of choice? Contractility (intrinsic) versus work (output) Compensation preserves work in the face of impairment

LV function in context

Best systolic function matches the LV to the periphery Optimizes efficiency over output Preserves the necessary margin to respond to increased need:

• Heart rate
• Volume change
• Incremental pressure

Decreases the risk of adverse remodeling and long term heart failure

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Indices of Left Ventricular Systolic Function

Index Sensitive to Inotropic Changes Dependence

• n Preload

Dependence

• n Afterload

Ejection Fraction

++ ++ +++

End Systolic Volume

+

• +++

Preload Recruitable Stroke Work

+++

• dP/dT

++++ ++ ++

The Charisma of LVEF

1. It's a number 2. It's easy to measure 3. It's based on the LV cavity, which is easy to see and to think about 4. It is based on a common test that is cheap (although profitable), harmless and widely available Has it shaped how we think about the LV? Does the body care about LVEF?

LVEF ≠ LV function

1. Very dependent on Preload and Afterload 2. Not based on accurate volumes or areas 3. Not very sensitive to Contractility 4. Can be misleading in hypertrophy and valve disease 5. Not reproducible

Contrast: change greater 10% in 17% of patients compared to non- contrast studies; improves correlation of echo LV volume and EF with MRI Multiple views: 3D LVEF

Overall LV systolic function

Wall motion Preload (size, pressure), heart rate and thickness Annular motion Flow based assessments Stroke volume Strain - Doppler and Speckle tracking

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How to build a ventricle

Longitudinal fibers LVEF 15%

Neil Ingels, PhD, Palo Alto Research Foundation

Circumferential Fibers LVEF 30%

How to build a ventricle How to build a ventricle

Spiral Fibers LVEF 100% (depending on pitch and radius of curvature) Opposing endocardial and epicardial spiral fibers

equalizes wall stress across endocardium, midwall, and epicardium minimizes net global torsion

How to build a ventricle

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Opposing spirals Longitudinal Circumferential

End Result:

Work distributed through all myocardial layers Good EF Good pressure generation

How to build a ventricle

Stroke volume Annular motion Pressure Subendocardial Subepicardial Midwall

Tissue Doppler

Long axis shortening reflected in mitral annular descent correlates with preload recruitable stroke work

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Strain Imaging

Avoids effects of translation and tethering Improves regional assessment and timing Identifies changes associated with ischemia, viability, fibrosis, infiltration

Myocardial Deformation Imaging

One dimensional strain: Tissue Doppler Imaging

Limitations:

Angle dependent single directional component Neighborhood effects

Strengths:

excellent temporal resolution Site specificity Best for structures with primary motion on axis

Best applications: Mitral and tricuspid annular excursion Dyssynchrony Strain (%) the amount of deformation caused by an applied force

L1 L0 L0 L1

ε = ∆L/L0 = -25%

Strain: Squish and Stretch

Translational motion that effects both sites will be cancelled

• ut

The concept of Speckle tracking:

Strain:

Myocardial deformation can occur in any direction in response to contraction or adjacent forces Tissue Doppler approaches: Axial velocity component only Insensitive to twist or non-axial velocities

Speckle tracking:

3 dimensional tissue sample Follow myocardial deformation in 2 dimensions with natural acoustic “Tagging”

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Myocardial deformation

123Sonography.com

Longitudinal Radial Circumferential

12/17/16 7 Deformation imaging in CAD

Detection:

GLS impaired with increasing severity of ischemia Value of > –17% predicts ischemic myocardium with good sensitivity, specificity and accuracy

Viability:

Radial strain > 17.2% has been reported to predict viability with similar accuracy as CMR. GLS < –13.7% correlates with SPECT viability index post-MI Addition of SR to WMSI improves detection of ischemic myocardium during DSE

Prognosis:

SR predicts mortality and add incremental value to clinical data and WMSI

Pokharel P et al. Clinical applications and prognostic implication of strain and strain rate imaging. Expert Rev Cardiovasc Ther 2015;13(7)

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Deformation imaging in Cardiac Amyloid and Dyssynchrony

Cardiac Amyloid: Deformation parameters detect myocardial involvement earlier than traditional 2D echocardiography GLS progressively worsens with increasing cardiac involvement Typical apical sparing pattern Impaired left ventricular LS and GLS has been reported to predict all-cause mortality and cardiac transplantation Ventricular Dyssynchrony: Various S and SR imaging-derived parameters are used to assess dyssynchrony to better predict CRT responders

Pokharel P et al. Clinical applications and prognostic implication of strain and strain rate imaging. Expert Rev Cardiovasc Ther 2015;13(7) Pokharel P et al. Clinical applications and prognostic implication of strain and strain rate imaging. Expert Rev Cardiovasc Ther 2015;13(7)

Cardiac Amyloid Dyssynchrony: M-mode

Anteroseptal infarction Dilated Cardiomyopathy with Dyssynchrony

Pokharel P et al. Clinical applications and prognostic implication of strain and strain rate imaging. Expert Rev Cardiovasc Ther 2015;13(7)

No LBBB LBBB

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Pre-CRT Post-CRT

Global Strain -10% Global Strain -14%

Deformation imaging in Onco-cardiotoxicity, HCM, and CHF

Onco-cardiotoxicity: Myocardial deformation parameters are sensitive markers of cardiotoxicity Early 10–15% decrease in GLS during chemotherapy predicts cardiotoxicity Cardiomyopathy and HCM: GLS is impaired in fibrotic segments and can serve as surrogate marker of myocardial fibrosis GLS associated with increased cardiac events in HCM CHF: Each SD improvement in GLS was associated with 1.62 times greater reduction in mortality than a similar improvement in LVEF GLS and circumferential strain are depressed in HFrEF

Pokharel P et al. Clinical applications and prognostic implication of strain and strain rate imaging. Expert Rev Cardiovasc Ther 2015;13(7)

Surveillance in Onco-Cardiology: Proposed Algorithm including GLS

Plana JC, et al. Eur Heart J Cardiovasc Imaging. 2014 Oct;15(10):1063-1093

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Pokharel P et al. Clinical applications and prognostic implication of strain and strain rate imaging. Expert Rev Cardiovasc Ther 2015;13(7)

HRpEF

Deformation imaging in Valvular Disease

Aortic Stenosis: GLS worsens with increasing severity of AS GLS predicts morality in AS GLS and peak longitudinal stain and strain rate with DSE predicts mortality in LFLG AS Aortic Insufficiency: GLS and GLS normalized to LVEDV are impaired in AI GLS can return to normal after AVR Mitral Regurgitation: GLS and SR in MR predicts less postoperative decrease in LVEF

Pokharel P et al. Clinical applications and prognostic implication of strain and strain rate imaging. Expert Rev Cardiovasc Ther 2015;13(7)

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2D Strain: Intraobserver Variability

Farsalinos KE, et al. REPRODUCIBILITY OF LEFT VENTRICULAR STRAIN Head-to-Head Comparison of Global Longitudinal Strain Measurements among Nine Different Vendors The EACVI/ASE Inter-Vendor Comparison Study. J Am Soc Echocardiogr 2015;28:1171-81

Interobserver Variability

• f Conventional and

Strain Parameters

Farsalinos KE, et al. REPRODUCIBILITY OF LEFT VENTRICULAR STRAIN Head-to-Head Comparison of Global Longitudinal Strain Measurements among Nine Different Vendors The EACVI/ASE Inter-Vendor Comparison Study. J Am Soc Echocardiogr 2015;28:1171-81

Deformation Imaging: Limitations

Main issues relate to inter-vendor issues! Test-retest performance is good, and better than conventional echo parameters. Proprietary nature of the software and resulting inter- vendor variability creates a lack of reproducibility Major roadblock for routine clinical use of Deformation Imaging. International efforts by professional societies are ongoing to establish norms and procedures to improve utility

Pokharel P et al. Clinical applications and prognostic implication of strain and strain rate imaging. Expert Rev Cardiovasc Ther 2015;13(7)