ASSESSMENT OF LV
FUNCTION IN 2012
Itzhak Kronzon, MD, FASE, FACC
Director, Cardiac Imaging
Lenox Hill Hospital, New York, NY
DISCLOSURES
• None
Evaluation of LV
1. Diastolic dimension
2. Systolic dimension
3. Ejection fraction
4. Wall thickness
5. Wall thickening
5. LV Mass
Markers of LV Dysfunction
1. Dilatation
2. Akinesis, Dyskinesis,
or Hypokinesis
3. Lack of thickening
4. Thinning
Left Ventricular Systolic Function:
It is not Just the Ejection Fraction
VISUAL ASSESSMENT OF LV FUNCTION
Visual Assessment:
 Global and Segmental function evaluation
 Endoocardial inward motion
 Endocardial thickening


16 or 17 segment model used
Each segment graded:
1- normal
3 - akinetic
2- hypokinetic
4 – dyskinetic
 Wall motion score index can be calculated

Visual estimation of ejection fraction
Segmental approach
-Easiest and least precise
-The score is the average of the individual segments score
-Does not account for remodeling
- Dilatation
- Expansion
- Extension
SIMPSON’S RULE / METHOD OF DISCS
Subdivide LV:
series of discs
• finite thickness
• measurable area
Each Disc volume =
(π x r2) x h
Sum of all disc volumes = LV volume
SIMPSON’S RULE / METHOD OF DISCS
SV (4C) = 97-42 = 55
EF (4C) = 55/97 = 57%
EDV=97 ml
SV (2C) = 99-39 = 60
SV = 97-42 = 55
EF (2C) = 60/99 = 61%
EF (4C) = 55/97 = 57%
ESV=42 ml
Overall EF = (57+61)/2 = 59%
EDV=99 ml
ESV=39 ml
LV FUNCTION - VOLUMES
-Echo volumes are smaller than ventriculogram volumes
(length foreshortening + contrast fills interstices)
-Men have larger diastolic volumes and LVEF
(58 vs 50ml/m2; 69% vs 64%)
-End systolic volumes correlate better than diastolic
3D ECHO FOR SEGMENTAL WALL MOTION ANALYSIS
Ejection Fraction is important, but
- Load dependent
No information about
-LV Volumes and C.0
-Segmental WMA
-dP/dT
The EF does not tell it all!!
EF
LVID
LVEDV
SV
CO
Normal
60%
5.0
125
75
5.3
HCM
80%
4.0
70
56
3.9
DCM
20%
8.0
344
69
4.8
Calculation of Systemic Blood Flow
C.O. = VTILVOT X AreaLVOT X HR
D = 2 cm
VTI = 24 cm
HR = 80
C.O. = 6,000 cc
1 x 1 x 3.14 x 24 x 80
C.O. can also be
calculated using LV inflow
and MV VTI
Otto
Coronary Blood Supply of LV Segments
Prox LAD
LAD
CIRC
RCA
Basic Concepts in
MYOCARDIAL CONTRACTILITY
DOPPLER ASSESSMENT OF LV FUNCTION
Rate of Ventricular Pressure Rise – dP/dT
MR jet velocity determined by LV-LA
pressure gradient
Good contractile function & low
atrial pressure fast rise in
MR jet velocity
Rate of rise in MR velocity
represents the rate of rise in
ventricular pressure during early
systole
DOPPLER ASSESSMENT OF LV FUNCTION
Rate of Ventricular Pressure Rise – dP/dT
dP= 36-4 = 32
dP / dT = 32
dT
DOPPLER ASSESSMENT OF LV FUNCTION
Rate of Ventricular Pressure Rise – dP/dT
dP/dT=1933
dP/dT=535
DOPPLER ASSESSMENT OF LV FUNCTION

Myocardial Performance Index
Ejection Time
Inflow
LV Outflow
Normal MPI <0.4
Worsening ventricular
function  bigger MPI
IVCT
IVRT
CONTRACTILITY - DEFINITIONS
Displacement
Velocity
Distance that a certain feature
(e.g. speckle) has moved between
two consecutive frames
Displacement per unit time - how
fast the location of a feature
changes
(measured in cm)
(measured in cm/sec)
Strain
Strain Rate
Fractional change in the length of
a myocardial segment
Rate of change in strain
(unit-less / %change)
(1/sec or sec-1)
TISSUE DOPPLER
Longitudinal
Velocity
Longitudinal systolic velocity
Systole
Diastole
Velocity
IVC
Peak Systole
VTI
IVR
A‘
(E‘) Em
Velocity Time Integral (VTI) = Systolic Displacement
Tissue Tracking = Color Coded Systolic Displacement
Courtesy of Geraci M
Spectral
Spectral TD
TD
Color
Color TD
TD
TISSUE DOPPLER - PULSE WAVE
Mitral Annular Systolic Velocity
 Index of global left ventricular function
 Mean systolic mitral annular velocity >7.5 cm/sec –
sensitivity 79%
preserved global left ventricular systolic function
specificity 88%
 Independent of endocardial resolution
S’
Gulati VK et al. AmJ Cardiolo 1996;77:979-984
PROBLEMS WITH TISSUE DOPPLER
• Translational
motion
• Tethering
• Doppler angle
Advantage of strain imaging
STRAIN ISOLATES THICKENING
L
L0
L0 = Original Length
L = Length of Deformed portion
Strain = (L-L0) / L0
Tissue velocity can result from
motion of the whole heart
MYOCARDIAL STRAIN
Used to describe elastic properties of cardiac muscle (Mirsky and Parmley: Circ Res, 1973)
Strain () =
+20%
L11-L00
L00
10
cm
L00
0%
-20%
Strain rate
L11
8
cm
12
cm
10
cm
STRAIN IMAGING
Strain
Measurement of tissue
deformation
Expressed as the change in a
segment size relative to the
original size
ε=
L - L0
L0
=
ΔL
L0
Lengthening / thickening – positive strain
Shortening / thinning – negative strain
STRAIN
Effect of acute ischemia on segmental strain
Pts studied during coronary balloon angioplasty
Kukulski at al, JACC 2003
Automated selection of stable
acoustic patterns
Green dots = initial position of
tracked point
Red dots = final position of
tracked point
MEASURING MYOCARDIAL STRAIN
Y
New location
dY
0
Old location
dX
X
Movement of the speckle represents tissue deformation
Tissue velocity (Tissue Doppler)
Tissue velocity (Speckle tracking)
VL
[m/s]
VT
[m/s]
Ultrasound beams
TVI - Longitudinalal velocity
components towards or away
from the probe
2D Strain - vector velocities in
the plane of imaging relative
to the direction of the muscle
contraction
Tracking Quality
Automatic evaluation of the
tracking quality at each myocardial
location
Normal
LAD
RCA
LCX
Courtesy Z. Friedman