echocardiography/angiography deepak nandan echocardiography/angiography deepak nandan

EVALUATION OF SYSTOLIC FUNCTION

ECHOCARDIOGRAPHY/ANGIOGRAPHY

DEEPAK NANDAN

“SYSTOLE”- CONTRACTION

“DIASTOLE”-TO SEND APART

Systolic function is affected by preload afterload,contractility and heart rate.

Asynchronous systolic contraction also may affect systolic function

Quantitative echo◦ LV VOLUME

◦ LV MASS

◦ EJECTION INDICES

STROKE VOLUME EJECTION FRACTION FRACTIONAL SHORTENING VELOCITY OF CIRCUMFERENCIAL FIBRE

SHORTENING

LV SYSTOLIC FUNCTION

Quantify LV function -MODES

M-Mode Modified Simpson’s Method Single plane area-length method Velocity of Circumferential Shortening Mitral Annular Excursion E-point to septal separation Rate of rise of MR jet Index of myocardial performance Subjective assessment

M-Mode Quantification Use Parasternal Short-Axis or Long-Axis

views to measure LVEDD and LVESD

May take several measurements at different levels and calculate average

Assumes that no significant regional wall motion abnormalities are present

Uncorrected (LVEDD)² - (LVESD)² LVEF = ----------------- X 100 (LVEDD)²

If apical contractility is normal

Corrected LVEF = Unc LVEF +(100 – Unc LVEF) X

15%)

5% hypokinetic, 0% akinetic, -5% dyskinetic, -10% aneurysm

Global Myocardial Function

• Fractional shortening (FS)– Assumes symmetric

contraction

• Ejection fraction (EF)

LVED LVESFS

LVED

2 2

2

LVED LVESEF

LVED

M-MODE-LINEAR MEASUREMENTS

EPSS

GRADUAL CLOSURE OF AORTIC VALVE

MEAN Vcf-rate of shortening of LV

INDIRECT M-MODE MARKERS

EPSSNORMAL ≤6mm

EF<50% >7mm

EF≤35% ≥13mm

Mitral Annular Excursion toward LV Apex

M-mode tracings in systole The magnitude of systolic motion is

proportional to the longitudinal shortening of the LV

Normal mitral annular systolic motion is 8mm+ (average 12 +/- 2 on apical4 or apical 2 views)

If motion is < 8 mm, the EF is likely < 50%

Velocity of Circumferential shortening Vcf is the mean velocity of LV shortening

through the minor axis

Vcf = FS/ET

ET is the time between LV isovolumetric contraction and isovolumetric relaxation

Measure by obtaining M-mode of AV opening to AV closure, aortic flow by doppler, or by an external pulse recording of carotid artery

NL values are > 1.0 c/s Slow Vcf may suggest diminished systolic

function

2-D MEASUREMENTS

Ejection Fraction

• Quantitative

- accuracy, reproducibility limited

- assumes shape of LV cavity

- best in symmetric ventricles

SIMPSONS RULE\ RULE OF DISC

Simpson’s Rule – the biplane method of disks

Volume left ventricle

- manual tracings in systole and

diastole

- area divided into series of disks

- volume of each disc(πr2x h )

summed = ventricular volume

LV-ED LV-ES

A4C

A2C

LV-ED LV-ES

LEFT VENTRICULAR MASS

TEICHOLZ /CUBED FORMULA

LV Mass Quantification 2D M-Mode method using parasternal short axis view or

parasternal long axis view

Assumes that LV is ellipsoid (2:1 long/short axis ratio)

Measurements made at end diastole

ASE approved cube formula: LV mass (g) = 1.04 [(LVID + PWT + IVST)3 - (LVID)3] X 0.8 + 0.6 LV mass index (g/m2) = LV mass / BSA

Small errors in M-Mode cause large errors in mass values. Can have off axis/tangential cuts due to motion.

LV Mass Quantification

LV mass = 1.04[(IVS + LVID + PWT)3 – (LVID)3] – 13.6 g

NL LV mass index for males: 93±22g/m2

NL LV mass index for females: 76±18g/m2

LV MASS BY 2-D

RWT = 2(PWT/LVID)

REGIONAL LEFT VENT FUNCTION

Regional Myocardial Function

• Assessment of motion of regions of the myocardium

• Useful for detection of myocardial ischemia– Leads to decreased or

paradoxical motion of the wall in affected areas

• Regions can be roughly mapped to coronary arteries

NONISCHEMIC RWMA

DIFF ISCHEMIC VS NONISCHEMIC

LBBB

DOPPLER EVALUVATION OF GLOBAL LVF

SCHEMATIC REP OF ASSESSMENT OF LV VOL

Stroke Volume and Cardiac Output

Flow = Cross sectional area (CSA) x Average velocity

Average velocity not usually measured directly

VTI = velocity-time integral

Area under the velocity curve for a single beatRepresents ‘stroke distance’

SV = VTI * CSA

Stroke Volume Measurement

Measurement of VTIMeasurement of CSA

Accurate measurement of CSA◦ Weakest link in the calculation◦ VTI very good for assessing change in cardiac

output with therapy, by following changes in VTI, since CSA is largely invariant in an individual

Measures forward flow only◦ Regurgitant fraction not considered◦ May over-estimate systemic cardiac output

Echocardiographic window in mechanically ventilated patients may be poor

Pitfalls in Echo Calculation of CO

WALL STRESS

LEFT VENTRICULAR dp/dt

CW doppler to measure rate of rise of MR jet may correlate to LVEFA slow rate of rise may indicate poor systolic functionMust have MR present, and good doppler study present (more difficult with eccentric jets)

INDEX

OF MYOCARDIAL PERFORMANCE

Index of Myocardial Performance Uses systolic and diastolic time intervals to evaluate global ventricular performanceSystolic dysfunction causes prolonged isovolumetric contraction time (ICT) and a shortened ejection time (ET). IMP = (ICT + IRT)/ET

Index of Myocardial Performance Normal LV: 0.39 +/- 0.05 LV, DCM: 0.59 +/- 0.10 Normal RV: 0.28 +/- 0.04 Primary Pulm Htn: 0.93 +/- 0.34

Use PW of AV inflow signal, or CW to get AV regurgitant signal

Also need to measure interval between AV closure and opening (AVco)

PW or CW to capture semilunar outflow signal to measure ejection time (ET)

IMP = (AVco – ET)/ET

Summary LV Mass Quantification: M-mode, Area-

length method, Truncated ellipsoid method, and Subjective assessment.

LV Volume Quantification: M-mode,

Subjective assessment

LV Function Quantification: Modified Simpson’s and Subjective Assessment by region.Also by M-mode, Single plane area length method, Velocity of Circumferential Shortening, Mitral Annular Excursion, EPSS, Rate of Rise of MR jet, Index of myocardial performance, etc

ANGIOGRAPHIC ASSESSMENT OF LV FUNCTION

Amout of passive tension or strectch on the ventricular walls prior to systole

This load determines end diastolic sarcomere length and force of contraction

This inturn decides stroke volume and cardiac output

LV PRELOAD

Afterload is the wall stress during ejection

Three major components are-peripheral resistance,arterial compliance,& peak intraventricular pressure.

Contractility is the inherent property of the myocardium to contract independent of the changes in pre & afterload

AFTERLOAD AND CONTRACTILITY

CONTRACTILITY INDICES

Isovolumic indices Maximum dp/dt Maximum (dp/dt)/p Vpm or peak([dp/dt]/28p) (dp/dt)/Pd at Pd=40 mm hg

Ejection phase indices LVSW LVSWI EF MNSER(mean normalised syst eject rate) Mean Vcf

EVALUATION OF SYSTOLIC PERFO

Dp/dt-max rate of rise of LV systolic pressure-oldest & widely used

Nl-1610±290 mmHg/sec

Isovolumic indices

EJECTION INDICES

Area within PV diagrams-most accurate

Other methods

LVSW=(LVSP−LVDP)SV(0.0136)LVSP&LVDP=MEAN SYST/DIAST PRSV=STROKE VOL IN ml0.0136=for converting mm Hg-ml into g-m

LVSW

LVSW –good measure in the absence of vol or pressure overload

Nl-90±30g-m

Values ≤25 indicate severe Lv syst failure & <20 prognosis is grave.

But reflects syst performance only when ventricle is homogenous in consistency-DCMP

In ext MI LVSW may be depressed even if contractility is normal

LVSW=(AoSP−PCWP)SV(0.0136)

Lv syst function can be assessed using only volume data from P-V diagram

EF=[(LVEDV−LVESV)/LVEDV]

EF/ Ejection time obtained from Ao pressure tracing =Mean normalised syst ejection rate

MNSER=(LVEDV−LVESV)/(LVEDVхET) NL-EF(angio)=.72±0.08

Nl MNSER(angio)=3.32±0.84EDV/sec

Vcf=velocity of the circumferential fiber shortening

Rate of shortening of lv myo fiber in a circmferential plane at the midpoint of the long axis of the ventricle

MeanVcf=end diast endocardial circum fiber length −end syst length

Vcf=(Ded−Des)/Ded(ET)

Nl-1.83±0.56ED circ/sec

Drawbacks-influenced by preload & afterload

An Lvef≤.40 indicates depressed lv contractility, if there is no loading to account for the reduction.

Interpretation of ejection phase indices are improved by consideration of the preload & afterload.

PRESSURE VOLUME LOOPS

Fundamental principle of end-systolic Pv analysis is that, at end-systole there is a single line relating LV chamber vol to pressure,unique for the level of contractility & independent of loading conditions.

Most reliable index of contractility

Insensitive to changes in pre,afterload& heart rate

Slope of the end syst pr vol curve is called elastance-sensitive parameter

ESPVR

Other indices

LVdp/dt max and EDV Slope of this as an

index of contractility

Inverse relation between the two ↑afterload→↑syst

wallstress→↓myocardial shortening

Stress-shortening relationship

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