Echocardiographic Evaluation of LV Diastolic Function
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Transcript of Echocardiographic Evaluation of LV Diastolic Function
Echo Teaching: Evaluation of LV Diastolic Function
23 Sep 2015Koh Choong Hou
Supervisor: Lim Choon Pin
Scope• Physiology of diastole
• Methods used to assess diastolic dysfunction
• Quiz
Definitions
• Traditional definition of diastole (in ancient Greek language the term διαστολε means expansion): includes the part of the cardiac cycle starting at the AoV closure - when LV pressure falls below aortic pressure - and finishing at the mitral valve (MV) closure
• Normal LV diastolic function may be clinically defined as the capacity of the LV to receive a LV filling volume able in its turn to guarantee an adequate stroke volume, operating at a low pressure regimen.
EAE Textbook of Echocardiography 2013
Why is Diastolic Function Important?
• Assess degree of diastolic impairment
• Assess left sided filling pressures – LA filling pressures
4 Phases of Diastole
• Isovolumic Relaxation. Between end of LV systolic ejection (AoV closure) and MV opening. LV pressure continues to fall while maintaining constant LV volume. Mainly attributed by active LV relaxation.
EAE Textbook of Echocardiography 2013
4 Phases of Diastole• LV Rapid Filling. LV pressures falls below LA pressure and MV
opens. Blood has an acceleration which achieves a maximal velocity (proportional to AV gradient), and stops when pressures equalise. Due to interaction between LV suction (active relaxation) and viscoelastic properties of myocardium (compliance)
EAE Textbook of Echocardiography 2013
4 Phases of Diastole
• Diastasis. LA and LV pressures almost equal. LV filling maintained by pulmonary veins inflow (LA = passive conduit) relationship with LV filling pressure. Mainly a function of LV compliance
EAE Textbook of Echocardiography 2013
4 Phases of Diastole
• Atrial Systole. Due to LA contraction, ends with MV closure. Mainly influenced by LV compliance, but also by pericardial resistance, atrial force and AV synchrony (PR interval)
EAE Textbook of Echocardiography 2013
Diastolic Dysfunction Grades
• Grade 1 = impaired relaxation pattern with normal filling pressure (1a = impaired relaxation pattern with increased filling pressure)
• Grade 2 = pseudonormalized pattern
• Grade 3 = reversible restrictive pattern
• Grade 4 = irreversible restrictive pattern
Assessment of diastolic function and diastolic heart failure. The Echo Manual, 3rd edition.
Stages of Diastolic Dysfunction
ASE/EAE “Practical Approach”
15 parameters
Mayo “Quick Screen”
4 parameters
Recommendations for the Evaluation of LV Diastolic Function by Echocardiography���
(JASE 2009, Vol 22, 107 – 133) ���
37 parameters���(excluding strain, twist, Tei, stress)
Basic Diastolic Function Indices / Parameters
• Mitral Inflow
§ E/A
§ DT
• Mitral Annular E’
§ E/E’
• IVRT
• Pulmonary Vein Doppler
§ Ar-A duration
• Propagation Velocity (Vp)
• LA size
Mitral Inflow Patterns
Mitral Inflow• As age increases, E velocity and E/A ratio
decrease, while DT and A velocity increase
• Factors affecting MV inflow:
§ HR and rhythm
§ PR interval (AV synchrony)
§ Cardiac output
§ Mitral annular size
§ LA function and compliance
1-3mm sample volume placed between MV leaflets tips
Quiz
Quiz
Quiz
Mitral Annular E’• Sample volume at/or within 1cm of septal / lateral
insertion sites of mitral leaflets, and adjusted as required to cover the longitudinal excursion of the mitral annulus
• Septal E’ > 8-10cm/s
• Lateral E’ velocity usually 25% higher
IVRT
To measure IVRT (i.e., the interval from aortic valve closure to mitral valve opening), a 3 to 4-mm sample volume is placed at the mitral leaflet tips. Next, the transducer beam is angulated toward the LV outflow tract until aortic valve closure appears above and below the baseline. An alternative technique is to use continuous wave Doppler echocardiography to record aortic and mitral flow simultaneously.
M-Mode MV Leaflets
Bonus Question
Flow Propagation (Vp)• Apical 4-chamber view, using color
flow imaging with a narrow color sector
• The M-mode scan line is placed through the center of the LV inflow blood column from the mitral valve to the apex
• Color flow baseline is shifted to lower the Nyquist limit so that the central highest velocity jet is blue
• Vp measured as slope of 1st alising velocity during early filling, measured from MV plane to 4cm distally into LV cavity
E/Vp• Should other Doppler indices appear inconclusive,
Vp can provide useful information for the prediction of LV filling pressures
• E/Vp ≥ 2.5 predicts PCWP > 15 mm Hg with reasonable accuracy
Rivas-Gotz C, Manolios M, Thohan V, Nagueh SF. Impact of left ventricular ejection fraction on estimation of left ventricular filling pressures using tissue Doppler and flow propagation velocity. Am J Cardiol 2003;91:780-4.
• Pulmonary venous inflow velocities are influenced by age
• Normal young subjects aged ︎40 years usually have prominent D velocities, reflecting their mitral E waves.
• With increasing age, the S/D ratio increases.
• In normal subjects, Ar velocities can increase with age but usually do not exceed 35 cm/s. Higher values suggest increased LVEDP
Pulmonary Vein Flow
A 2-mm to 3-mm sample volume is placed ︎0.5 cm into the pulmonary vein for optimal recording of the spectral waveforms
Ar-A duration
• LA volume index >=34ml/m2 is an independent predictor of: Death, Heart failure, Atrial fibrillation, Ischemic stroke
• Causes of LA enlargement: Anemia and other high-output states; AF/AFL; Mitral valve disease in the absence of diastolic dysfunction
Myocardial Performance (Tei) Index
AR CW Doppler
Noninvasive Assessment of Left Ventricular Relaxation Using Continuous-Wave Doppler Aortic Regurgitant Velocity Curve. Kazuhiro Y. CirculationVolume 91(1):192-200 January 1, 1995
T -the time interval between the onset of aortic
regurgitation and the regurgitant velocity
corresponding to 1/2 of the maximal velocity
P=4V2 V- is aortic regurgitation
velocity in meters per second at 20 ms after the onset of
regurgitation
ΔP/Δt-AR correlated with catheter-derived −dP/dtmax (r=.92, P<.01)
A, Plot showing relation between catheter-derived −dP/dtmax and Doppler-derived ΔP/Δt-AR. Dashed line is a line of identity, and solid line is a regression line.
B, Mean vs the difference of catheter-derived −dP/dtmax minus Doppler-derived ΔP/Δt-AR. Solid line indicates mean difference, and dashed lines are 2 SD of mean difference.
Mayo Quick Screen
• LV Size / Function
• LA Volume
• E/A, DT
• E/e’