1. ASSESSMENTOFDYSSYNCHRONY
DR AWADHESH KUMAR
SHARMA
DM CARDIOLOGY
FINAL YEAR
DEPARTMENT OF
CARDIOLOGY
PGIMER & DR RML HOSPITAL
NEW DELHI

2. INTRODUCTION
 Cardiac resynchronization therapy (CRT) using
atrio biventricular pacing has evolved into a useful
therapeutic option for patients with heart failure,
refractory to optimal medical therapy.
 Improvements in quality of life, morbidity, mortality,
severity of mitral regurgitation (MR) and left
ventricular (LV) function have been demonstrated in
large randomized clinical trials but the treatment is
invasive and expensive.
Iuliano S, Fisher SG, Karasik PE, Fletcher RD, Singh SN: Department of Veterans Affairs Survival Trial of
Antiarrhythmic Therapy in Congestive Heart Failure. QRS duration and mortality in
patients. Am Heart J 2002, 143:1085-1091.

3. INTRODUCTION CONTD……
 Besides, about one third of patients remain
unresponsive in spite of the device implantation
using the existing criteria.
 However, 30–40% of patients selected on the basis
of a prolonged QRS do not receive benefit by CRT
since they do not show any significant inverse LV
remodeling (a ≥ 15% reduction of LV end-systolic
volume six months after device implantation).
Cleland JG, Daubert JC, Erdmann E, Freemantle N, Gras D, Kappenberg L, Tavazzi L: Cardiac Resynchronization – Heart Failure
(CARE-HF) Investigators. The effect of cardiac resynchronization therapy on morbidity and mortality in heart failure. N Engl J Ned
2005, 352:1539-1549.

4. INTRODUCTION CONTD…..
 Furthermore, QRS duration does not accurately
distinguish responders to CRT .
 Although factors responsible for the absence of
favourable response may be lead dislodgement or
inappropriate location of LV lead, mechanical
dyssynchrony (particularly intra-ventricular
dyssynchrony) plays a important role.
 There is thus a need to carefully identify the patients
most likely to benefit by this intervention using indices of
mechanical dyssynchrony.
J Am Coll Cardiol 2002,40:1703-1719.

5. DEFINITIONS OF DYSSYNCHRONY
 Electrical Vs Mechanical Dyssynchrony
Electrical Dyssynchrony refers to a prolonged
conduction time in the ventricles resulting in a
prolonged QRS duration.
Mechanical Dyssynchrony is the mechanical
discoordination , usually associated with
simultaneous contraction and stretch in different
regions of the LV as well as delays in the time to
peak contraction from one segment to another.

7. DELETERIOUS HEMODYNAMIC EFFECTS OF LV DYSSYNCHRONY
Diminished SV & CO due:
 Reduced diastolic filling
time
 Weakened contractility
 Protracted MV regurgitation
 Post systolic regional
contraction
Atrio-
ventricular
Inter-V
Intra-V
Cazeau, et al. PACE 2003; 26[Pt. II]: 137–143

8. TOOLS FOR DYSSYNCHRONY ASSESSMENT
 2D Echocardiography
 3D Echocardiography
 MRI

9. ECHOCARDIOGRAPHIC ASSESSMENT

10. ATRIOVENTRICULAR DYSSYNCHRONY
 AV dyssynchrony reduces the duration of
ventricular filling, thus inducing the appearance of
diastolic mitral and tricuspid regurgitation and
reducing stroke volume.
 Atrio-ventricular (AV) dyssynchrony occurs in
patients with dilated cardiomyopathy and first
degree AV block and was the first objective of CRT
by bicameral pacemakers in the early 1990s.

11. ATRIOVENTRICULAR DYSSYNCHRONY
CONTD……
Atrioventricular dyssynchrony- is said to be present when
diastolic filling period (DFP) occupies less than 40% of
cardiac cycle (measured by R-R interval.
1. To obtain DFP, obtain the apical four-chamber view with mitral
valve in the centre of the frame.
2. Using pulsed Doppler with the sample volume placed at the
tips of mitral leaflets; obtain a spectral display of mitral
inflow pattern.
3. Measure the time from the onset to the end of the spectral
display- this represents DFP.
4. Measure the R-R interval using any two consecutive regular
beats.
Divide DFP with R-R interval and multiply by hundred to obtain a
percentage value .

12. Assessment of atrioventricular dyssynchrony using pulsed-Doppler
measurement of mitral inflow velocity at mitral leaflet tips

13. INTERVENTRICULAR DYSSYNCHRONY
 Inter-ventricular dyssynchrony represents the
discordance between the times of right ventricular
(RV) and LV contraction.
 Interventricular mechanical dyssynchrony is
assessed by measuring the interventricular
mechanical delay.
Cardiac resynchronization therapy and the emerging role of echocardiography
(Part 1): indications and results from current studies. J Am Soc Echocardiogr
2007, 20:70-75.

14. INTERVENTRICULAR DYSSYNCHRONY CONTD…..
 PW or CW Doppler images of aortic and pulmonary
flow velocities are currently used to measure the
inter-ventricular mechanical delay (IVMD).
 A difference of IVMD values of > 40 ms and
values of LV PEP of >140 ms are considered
pathological .
Echocardiographic modeling of cardiac dyssynchrony before and during
multisite stimulation: a prospective study. Pacing Clin Electrophysiol 2003,
26:137-143.

15. INTERVENTRICULAR DYSSYNCHRONY
 To obtain time to onset of LV ejection, obtain the
apical five-chamber view and place the pulsed-
Doppler sample volume at the left ventricular
outflow tract (LVOT).
 Measure the time from the onset of QRS complex
to the onset of the pulsed-Doppler flow velocity.
This is the LV pre-ejection period (LVPEP).
Cardiac resynchronization therapy and the emerging role of echocardiography
(Part 2); the comprehensive examination. J Am Soc 2007, 20:76-90.

16. INTERVENTRICULAR DYSSYNCHRONY
 To obtain the time to onset of RV ejection, obtain the
Right ventricular outflow tract (RVOT) view (para-sternal
short axis) and place the pulsed Doppler sample volume
at RVOT.
 Measure the time interval from onset of QRS complex to
the onset of pulse-Doppler velocity curve. This is the RV
pre ejection period (RVPEP).
 The difference of LVPEP and RVPEP gives
interventricular mechanical delay .

17. LIMITATIONS
 Presence of pulmonary arterial hypertension and/or
RV systolic dysfunction, which can prolong RV PEP.
 Concomitantly impaired increase of LV pressure in
very severe CHF.

18. INTERVENTRICULAR DYSSYNCHRONY
CONTD…..
 Alternatively, pulsed Tissue Doppler can be used to
determine IVMD by measuring the time from QRS
onset to the peak myocardial systolic velocities
(Sm) of the RV free wall (tricuspid annulus) versus
the same time of LV lateral mitral annulus (apical 4-
chamber view) .
Echocardiographic evaluation of cardiac resynchronization therapy: ready for
routine clinical use? A critical appraisal. J Am Coll Cardiol 2004, 44:1-9.

19. INTRAVENTRICULAR DYSSYNCHRONY
 Intraventricular dyssynchrony is the principal factor
responsible for contractile dysfunction, the one
most affected by and most predictive of response to
resynchronization therapy.
 Large number of indices have been described and
evaluated in studies using several
echocardiographic modalities.
Cardiac resynchronization therapy tailored by echocardiographic evaluation of
ventricular asynchrony. J Am Coll Cardiol 2002, 40:1616-1622.

20. ASSESSMENT OF INTRAVENTRICULAR
DYSSYNCHRONY
1. M-mode measurement of septal-posterior wall motion delay
(SPWMD)
2. TDI for measurement of time to peak systolic longitudinal
velocity of various myocardial segments & time to peak
systolic longitudinal strain and strain rate of various
myocardial segments
3. Assessment of radial dyssynchrony using speckle-tracking
4. Three-dimensional echocardiography
Ventricular asynchrony predicts a better outcome in patients with chronic heart
failure receiving cardiac resynchronization therapy. J Am Coll Cardiol
2002, 40:536-545.

21. M-MODE MEASUREMENT OF SPWMD
This is the simplest technique to assess the septal to
posterior wall motion delay.
1. Position the M-Mode cursor at the papillary muscle
level in either the parasternal long or short axis
view.
2. Keeping the sweep speed from 50-100
mm/second, measure the time delay from peak
inward septal motion to peak inward posterior wall
motion.
Cardiac resynchronization therapy and the emerging role of echocardiography; the
comprehensive examination. J Am Soc 2007, 20:76-90.

25. M-MODE MEASUREMENT OF SPWMD ……….
 In the original experience of Pitzalis et al on 20
patients with advanced heart failure, a SPWMD
(determined in parasternal short-axis view) of >130
ms was considered pathological and SPWMD
predicted inverse LV remodeling and long-term
clinical improvement after CRT, with 100%
sensitivity, 63% specificity and 85% accuracy .
Cardiac resynchronization therapy tailored by echocardiographic evaluation of
ventricular asynchrony. J Am Coll Cardiol 2002, 40:1616-1622.

26. ADVANTAGE & LIMITATION OF SPWMD
 The main advantages of this method correspond to the low-
cost technique and the availability in all the echocardiographic
machines.
 The limitations include the impossibility to measure SPWMD
in patients with a poor acoustic window, previous septal or
posterior wall myocardial infarction, or abnormal septal motion
secondary to RV pressure or volume overload.
 In addition, M-mode can only visualize dyssynchrony of the
anterior septum or posterior wall whereas other LV walls can
be involved.

27. COLOR TDI IMAGING, M-MODE
M-MODE MEASUREMENT OF SPWMD is quite simple and widely available but
it is often quite difficult to identify the peaks in both the walls. To overcome
this shortcoming, color TDI M-mode is now recommended as it enables the
identification of the peak systole by the sharp color transition
1. Position the M-Mode cursor at the papillary muscle level in either the
parasternal long or short axis view.
2. Keeping the sweep speed from 50-100 mm/second, select color TDI.
3. Measure the time delay from peak inward septal motion to peak inward
posterior wall motion, as indicated by the sharp color transition .
A value > 130ms signifies dyssynchrony and response to CRT
with a high degree of sensitivity.

29. LATERAL WALL POST-SYSTOLIC DISPLACEMENT
(LWPSD)
 A another method, reported by Sassone et al, determines lateral wall
post-systolic displacement (LWPSD), measured as the difference of
intervals from QRS onset to maximal systolic displacement of the basal
LV lateral wall (assessed by M-mode in the apical 4-chamber view) and
from QRS onset to the beginning of transmitral E velocity (assessed by
pulsed Doppler of mitral inflow).
 A positive LWPSD i.e. a longer interval to maximal inward displacement
of LV lateral wall than the interval to opening of the mitral valve, identifies
a severe post-systolic contraction and has been demonstrated to be an
independent predictor of CRT response in 48 patients with end-stage
heart failure and left bundle branch block.
Sassone B, Capecchi A, Boggian G, Gabrieli L, Saccà S, Vandelli R, Petracci E, Mele D: Value of baseline left lateral wall
postsystolic displacement assessed by m-mode to predict reverse remodeling by cardiac resynchronization therapy. Am J
Cardiol 100(3):470-5. 2007, Aug 1; Epub 2007 Jun 15
 QRS onset to maximal
systolic displacement
of the basal LV lateral
wall (assessed by M-
mode in the apical 4-
chamber view)
QRS onset to the
beginning of
transmitral
E velocity (assessed
by pulsed Doppler of
mitral inflow)
Minus

30. Methodology for measuring lateral wall post-systolic displacement (LWPSD). It is measured as the difference
of the time interval from QRS onset to maximal systolic displacement of the basal LV lateral wall (assessed
by M-mode in the apical 4- chamber view) (upper panel) and the time interval from QRS onset to the
beginning of transmitral E velocity (assessed by pulsed Doppler of mitral inflow) (lower panel). In this
example, the positive value of the difference indicates the co-existence of segmental post-systolic contraction
and diastolic relaxation. (Modified from Sassone B et al, Am J Cardiol 2007;100:470–475).

31. LATERAL WALL POST-SYSTOLIC DISPLACEMENT
(LWPSD)……….
 Of interest, despite evaluating intra-ventricular dyssynchrony
based on delay of a single myocardial wall, LWPSD could predict
CRT response.
 This may rely to the fact that, in the presence of left bundle
branch block, the lateral wall is the latest to be activated,
theoretically representing the optimal target for LV lead
positioning.
 This method has not yet tested in patients without left bundle
branch block and its diagnostic accuracy is unknown.
 In addition. it needs the identical heart rate when measuring the
M-mode and pulse Doppler imaging.

32. TDI FOR ASSESSMENT OF INTRAVENTRICULAR
DYSSYNCHRONY
 Measurement of time to peak- systolic longitudinal
velocity-
 Assessment of longitudinal shortening velocities ie the
time of myocardial systolic velocities (Sm) from the
apical window with TDI has been studied extensively
and several indices proposed.
 There are two approaches possible- pulsed-TDI or
color-coded TDI but owing to several limitations with
pulsed-TDI, color TDI is now the preferred method.
Doppler myocardial imaging to evacuate the effectiveness of
pacing sites in patients receiving biventricular pacing.
J Am Coll Cardiol 2002, 39:489-499.

33. MEASUREMENT OF TIME TO PEAK- SYSTOLIC
LONGITUDINAL VELOCITY-
1. Obtain a noise free ECG trace and good quality 2D image from the
apical window with the LV cavity in the centre of image sector and the
depth adjusted to include the mitral annulus.
2. Activate color TDI, adjusting the sector width so as to keep the frame
rate > 90 frames/second.
3. Suspend breathing if possible and acquire 3-5 beats (sinus rhythm) or
more (in case of ectopics).
4. The number of LV segments to be evaluated include mainly a 12-
segment model (LV basal and middle segments in 4-, 2- and 5-
chamber views) whereas LV apical segments are not considered
reliable because of the basal apical myocardial gradient own of Tissue
Doppler.

34. Methodology for measuring
pulsed Tissue Doppler
derived time to peak Sm
and time to onset Sm (left
panel).
In the right panel
measurements of time to
peak Sm (upper panel) and
of time to onset Sm (lower
panel) are depicted.
Am=Myocardial atrial
velocity,
CTm = Contraction time,
Em = Myocardial early
diastolic velocity,
RTm = Myocardial
relaxation
time,
Sm = Myocardial systolic
velocity.
Mod from Agler DA et al, J
Am Soc Echocardiogr
2007;20:76–90.

35. TIME TO PEAK- SYSTOLIC LONGITUDINAL
VELOCITY
 The most widely used measurements correspond to the time
interval between the onset of ECG derived QRS and the Sm
peak (= time to Sm peak) and the time interval between the
onset of QRS and the onset of Sm (= time to Sm onset), which
correspond to LV PEP.
 Intra-ventricular mechanical delay has been defined for
differences of > 65 ms of time to Sm peak between LV
segments.
Intra-left ventricular electromechanical asynchrony: a new independent
predictor of severe cardiac events in heart failure patients. J Am Col Cardiol
2004, 43:248-256.

36. TIME TO PEAK- SYSTOLIC LONGITUDINAL
VELOCITY CONTD……
 Receiver-operator characteristic curve analysis demonstrated
that this cut-off value yielded a sensitivity and specificity of
80% to predict clinical improvement and of 92% to predict LV
reverse remodeling in 85 patients with end-stage heart failure,
QRS duration > 120 ms, and left bundle-branch block.
Intra-left ventricular electromechanical asynchrony: a new independent
predictor of severe cardiac events in heart failure patients. J Am Col Cardiol
2004, 43:248-256.

37. LIMITATION OF PW TISSUE DOPPLER
 The main limitation of PW Tissue Doppler
corresponds to the impossibility of measuring the
time intervals of different segments during the same
cardiac cycle.
 It is also necessary to take into account that the Sm
recorded in apical views reflects LV longitudinal
shortening and not circumferential contraction.

38. COLOUR TISSUE DOPPLER
1. Off-line colour Tissue Doppler derived Tissue
Velocity Imaging (TVI),
2. SRI

39. COLOUR TISSUE DOPPLER
 Off-line colour Tissue Doppler derived Tissue Velocity
Imaging (TVI), Tissue Synchronization Imaging (TSI)
and SRI can be used to assess intra-ventricular
dyssynchrony in the longitudinal plane (apical views).
 The common advantages of these techniques is the
possibility of measuring the dyssynchrony of opposite LV
walls (= horizontal dyssynchrony) and of different
segments of the same LV wall (= vertical dyssynchrony)
in a given view, from the same cardiac cycle.

40. Methodology for recording and measuring intra-ventricular horizontal and vertical
dyssynchrony by off-line color Tissue Doppler techniques. Horizontal
dyssynchrony occurs between opposite walls. Vertical dyssynchrony is
between different segments of the same wall.

41. COLOUR TISSUE DOPPLER
 TVI measures the time to Sm peak (Ts) or the time to
Sm onset in LV basal and middle segments of the three
standard apical views.
 By identifying the presence of one or more differences >
50 ms among regional times of Sm onset, suggests
significant intraventricular dysynchrony .
 Ghio and coworkers have demonstrated that
intraventricular dyssynchrony is detectable even in 29.5
% of patients with advanced LV dysfunction but normal
QRS duration by this criteria.
Echocardiography 2006, 23:709-712.
Sample of time to peak (Ts) measured by off-line color TVI pre and post CRT at the level of anterior septum
and postero-lateral wall, in apical 5-chamber view. Aortic valve opening (AVO) and closure (AVC) are derived by
previous placement of markers on the onset and the end of LV Doppler outflow. Pre-CRT Ts of postero-lateral wall
(upper panel) is clearly delayed in comparison to Ts of anterior septum. Post-CRT the time duration of Ts between
the two walls is clearly shortened (lower panel). (Modified from Innelli P et al, Echocardiography 2006;23:709–
716)

42. COLOUR TISSUE DOPPLER CONTD….
o Using a LV 12-segment model. A dyssynchrony index (DI)
or Yu index can be derived as the Standard deviation of the
average values of Ts ie (Ts-SD).
o As per Yu et al Ts-SD of > 32.6 ms predicts inverse LV
remodeling after CRT with 100% sensitivity, 100% specificity
and 100% accuracy in 30 candidates to CRT.
Yu CM, Fung WH, Zhang Q, Sanderson JE, Lau CP: Predictors of
left ventricular remodeling after cardiac resynchronization
therapy for heart failure secondary to idiopathic or dilated
cardiomyopathy. Am J Cardiol 2003, 91:684-688.

43. DYSSYNCHRONY INDEX (DI)
 Methodology of calculation of
Dyssynchrony Index and is ability in
predicting LV inverse remodeling.
 In the upper panel methodology of
calculation of Dyssynchrony Index, i.e.,
the standard deviation of Ts (Ts-SD)
measured in the basal and mid-
segments visualizable in the apical
views.
 In the lower panel, Ts-SD shows the
ability to predict an effective LV inverse
remodeling after CRT (lower panel).
Values of TS-SD > 32.6 (black triangles)
predict an effective LV reverse
remodeling (DLVVs = delta left
ventricular end-systolic volumes) after
CRT. Patients with pre-CRT values of
Ts-SD < 32.6 (empty circles) do not
present significant LV inverse
remodeling at follow-up.
(Modified from Yu CM et al, Am J
Cardiol 2003;91:684–688)

44. TISSUE SYNCHRONIZATION IMAGING (TSI)
 TSI is an implementation of Ts method.
 It displays Ts (time to Sm peak) in multiple LV segments by
colour coding wall motion green (corresponding to early
systolic contraction) or red, which corresponds to delayed
contraction (sensitivity = 87%, specificity = 81% and accuracy
= 84% at a cut-off value of 34.4 ms in 56 patients with severe
heart failure).
A novel tool to assess systolic asynchrony and identify responders of cardiac
resynchronization therapy by tissue synchronization imaging. J Am Coll Cardiol 2005,
45:677-684.

45. Four-dimensional tissue synchronization imaging (TSI) of a normal individual. From
the different views (left), a three-dimensional impression of the left ventricle is
reconstructed (middle). The entire three-dimensional image of the left ventricle is
green indicating no dyssynchrony. Post- processing allows the display of the
different segments in a polar map format (right) to further facilitate identification of
the site of latest activation.

46. Four-dimensional tissue synchronization imaging (TSI) of a patient with left ventricular
dyssynchrony. From the different views (left), a three-dimensional impression of the left
ventricle is reconstructed (middle). The region of latest activation is indicated in red. Post-
processing yields the polar-map format (upper right) indicating in red the site of latest
activation (anteroseptal), and further calculations can be performed (lower right) to
further quantify the extent of left ventricular dyssynchrony using different parameters.

48. SPECKLE TRACKING
 This is a 2-D strain technique and has been used
to assess radial dyssynchrony before/after CRT.
 Speckle tracking has been applied to routine mid-
ventricular short-axis images to calculate radial
strain from multiple circumferential points averaged
to six standard segments.

50. STRAIN
 The principal benefit of LV shear strains is amplification of the
15% shortening of myocytes into 40% radial LV wall
thickening, which ultimately translates into a >60% change in
LV ejection fraction.
 Left ventricular shearing increases towards the
subendoardium, resulting in a subepicardial to subendocardial
thickening strain gradient.

51. STRAIN……
 Dyssynchrony from timing of peak radial strain has
been demonstrated to be correlated with Tissue
Doppler measures.
 A time difference ≥ 130 ms between the radial strain
peak of LV posterior wall and anterior septum has
shown to be highly predictive of an improved EF
during follow-up, with 89% sensitivity and 83%
specificity.
Circulation 2006, 113:960-968.

54. STRAIN…….
 Another possibility, proposed by Porciani et al,
considers the time spent by 12 LV segments in
contracting after AVC, i.e., during the isovolumic
relaxation time, and measures the sum of the time
of strain tracing exceeding AVC (ExcT) on the 12 LV
basal and mid-segments (cut-off value = 760 ms,
93.5% sensitivity and 82.8% specificity).
Eur Heart J 2006, 27:1818-1823.

55. Methodology for measuring time of exceeding aortic valve closure contraction. The
sum of the time of strain tracing exceeding aortic valve closure (ExcT) is calculated
on the 12 LV basal and middle segments in the standard apical views.
AVO = aortic valve opening, AVC = aortic valve closure(Modified from Porciani MT
et al, Eur Heart J 2006;27:1818–1823)

56. DYSSYNCHRONY ASSESSMENT
The data thus obtained can be used to calculate any of the
several proposed dyssynchrony indices, as below –
 Delay in time-to-peak-systolic velocity between
opposing walls- > 65msec.
 Maximum delay in time-to-peak-systolic velocity
between any two myocardial segments- >100msec.
 Standard deviation of the time-to-peak-systolic velocity
of the 12 basal and mid LV segments- > 33msec.
J Am Coll Cardiol Img 2010;3:132– 40

57. THREE-DIMENSIONAL ECHOCARDIOGRAPHY FOR
ASSESSMENT OF DYSSYNCHRONY
 Real time 3D echocardiography (RT3DE) is a relatively
new but very promising tool in the assessment of
dyssynchrony.
 The greatest advantage of RT3DE is that it enables the
comparison of synchrony in all segments in the same
cardiac cycle.
 Quantitative analysis involves using software which
enables LV volumetric analysis with semiautomatic edge
detection to produce a cast of the LV cavity.
Eur Heart J 2006, 27:859.

58. THREE-DIMENSIONAL ECHOCARDIOGRAPHY FOR
ASSESSMENT OF DYSSYNCHRONY…….
o The global LV volumetric dataset has been used to determine a
dyssynchrony index that corresponds to the standard deviation of
the average of the time intervals needed by multiple LV segments
to reach minimal end-systolic volume.
o This index is expressed as the percent value of the overall
cardiac cycle, in order to be able to compare patients with
different heart rates.
o CRT responders show a significant reduction of this 3-D
dyssynchrony index, which parallels the reduction of LV
enddiastolic volume and the increase in EF
3D echocardiography reduces the time needed to assess left ventricular synchronicity in
heart failure patients with clinical indication to cardiac resynchronization therapy. (abs)
Eur Heart J 2006, 27:822.

59. LIMITATIONS OF 3-D ECHOCARDIOGRAPHY
 The limitations of 3-D method are its suboptimal
feasibility (<80%), its temporal resolution of about
40–50 ms, and its inability to distinguish active from
passive motion or to make analysis in the presence
of atrial fibrillation and/or recurrent premature
beats.

60. 3-D derived time-volume curves of 16-segment model. Presentation 3-D derived
time-volume curves of 16-segment LV model in a patient with intra-ventricular
dyssynchrony. Each LV myocardial segment is codified by a different colours.

61. THREE-DIMENSIONAL ECHOCARDIOGRAPHY FOR ASSESSMENT OF
INTRAVENTRICULAR DYSSYNCHRONY SHOWING SEGMENTAL TIME-TO-
MINIMUM VOLUME IN SEGMENTAL SHELL-VIEW DISPLAY

63. MRI FOR DYSSYNCHRONY
 VENC-MRI and cine-MRI were performed in 20 patients with heart failure NYHA
class III and reduced ejection fraction before CRT device implantation.
 The interventricular mechanical delay (IVMD) was assessed by VENC-MRI as the
temporal difference between the onset of aortic and pulmonary flow.
 Intraventricular dyssynchrony was quantified by cine-MRI, using the standard
deviation of time to maximal wall thickening in sixteen left ventricular segments.
 RESULTS
 14 patients (70 %) clinically responded to CRT. A similar accuracy was found to
predict the response to CRT by measurements of the IVMD.
 ALSO data analysis of the IVMD is significantly less time-consuming.
Quantification of mechanical ventricular dyssynchrony: direct comparison
of velocity-encoded and cine magnetic resonance imaging.
Ref. JACC 2011 Jun;183(6):554-60. Epub 2011 Apr 12.

64. LV DYSSYNCHRONY AS ASSESSED WITH PHASE
ANALYSIS FROM GATED MYOCARDIAL PERFUSION
SPECT (GMPS)
Journal of the American College of Cardiology,
Vol. 49, No. 16, 2007

65. Example of a patient without left ventricular (LV) dyssynchrony on gated myocardial
perfusion single-photon emission computed tomography (GMPS). The non-
normalized (upper panel) and normalized (lower panel) phase distributions are
nearly uniform, and the corresponding phase histograms are highly peaked, narrow
distributions.

66. Example of a patient with LV dyssynchrony derived from GMPS. The non-normalized
(upper panel) and normalized (lower panel) phase distributions show significant non-
uniformity and the corresponding phase histograms are widely spread distributions.

67. LIMITATIONS OF GATED MYOCARDIAL
PERFUSION SPECT (GMPS)
 Several limitations need to be acknowledged.
 First, follow-up data after CRT implantation were
not available; therefore, it remains to be determined
what the value of GMPS is for prediction of
response to CRT.
 Another limitation of GMPS, in general, is that
GMPS is less suitable than echocardiography for
follow-up after CRT implantation, due to the
radiation burden.

70. RV DYSSYNCHRONY

72. MAIN TECHNIQUES, PARAMETERS AND REFERENCE VALUES FOR
DETECTION OF INTRA-VENTRICULAR DYSSYNCHRONY

73. SENSITIVITY, SPECIFICITY AND ACCURACY, AND CONFIRMATORY OR
CONFLICTING DATA OF THE MAIN TECHNIQUES

74. DYSSYNCHRONY IN THE NARROW QRS PATIENT
POPULATION
 If CRT can be shown to be of benefit to these patients(narrow
QRS), the application of echocardiographic assessment of
dyssynchrony is potentially of great importance for patient
selection for therapy.
 Trials showing benefit of CRT-
 Bleeker et al showed CRT to benefit in 33 patients with NYHA
class III/VI heart failure and EF less than or equal to 35%, but
QRS less than 120 milliseconds, who had mechanical
dyssynchrony defined as a septal-to-lateral wall time-to-peak
systolic velocity delay of greater than or equal to 65 milliseconds
by TD.(J Am Coll Cardiol 2006;48:2243-50.)

75. DYSSYNCHRONY IN THE NARROW QRS PATIENT
POPULATION……….
 Yu et al reported results on 51 patients with heart failure with narrow QRS (120
milliseconds) who had CRT based on TD measures of dyssynchrony. CRT resulted in
significant reductions of LV end-systolic volume, and improvement of NYHA class, 6-
minute hall-walk distance, and EF, similar to patients with wide QRS who underwent
CRT.(J Am Coll Cardiol 2006;48:2251-7)
 The first randomized trial of CRT in patients with heart failure with narrow QRS
complexes (130 milliseconds), known as the RethinQ trial, was published by Beshai et al
.This trial failed to show a therapeutic effect of CRT on the primary end point of peak
myocardial oxygen consumption. Although a positive effect of CRT was observed on the
secondary end point of improvement in NYHA functional class, other parameters
including quality-of-life score, 6-minute walk test, and LV reverse remodeling did not
change.
(N Engl J Med 2007;357:2461-71.)

77. CONCLUSIONS
In patients with systolic heart failure and a QRS
duration of less than 130 msec, CRT does not
reduce the rate of death or hospitalization for
heart failure and may increase mortality. (0ct
2013)

78.  According to ASE the dyssynchrony reporting in
cases with borderline ECG should not include a
recommendation whether a patient should undergo
CRT or not, as this should be a clinical decision on
a case-by-case basis.

79. POST CRT AV DELAY OPTIMIZATION
 Because the ventricles are paced in CRT, the AV
delay needs to be programmed.
 The optimal programmed AV delay for an electronic
pacemaker has been defined as the AV delay that
allows completion of the atrial contribution to
diastolic filling resulting in most favorable preload
before ventricular contraction.

80. AV DELAY OPTIMIZATION
 An AV delay programmed too short will result in absence or
interruption of the atrial component (mitral A wave) by the premature
ventricular contraction and closure of the mitral valve.
 An AV delay programmed too long can result in suboptimal LV
preload or diastolic MR, or may even allow native LV conduction,
which defeats the purpose of CRT.
 A simplified Doppler screening protocol after CRT implantation is
proposed using pulsed Doppler mitral inflow, because no consensus
currently exists for the routine performance of AV optimization after
CRT.

81. AV DELAY OPTIMIZATION………
 Auricchio et al concluded that although AV delay often positively impacts
hemodynamics, LV resynchronization of intraventricular dyssynchrony is more
important.(Circulation 1999;99:2993-3001)
 A larger report of 215 patients undergoing Doppler guided AV optimization found
small differences between the baseline and post-AV optimization average AV delay
(120 vs 135 milliseconds, respectively).
 Furthermore, AV optimization enhanced LV hemodynamics in only a minority of
patients with CRT, suggesting that a significant percentage of patients do not need
to undergo formal AV optimization.
 Patients with intra-atrial conduction delay at baseline appeared to benefit greatest
by prolonging the AV delays (150-250 milliseconds) during AV optimization.
Kedia N, Ng K, Apperson-Hansen C, et al. Usefulness of atrioventricular delay optimization using Doppler
assessment of mitral inflow in patients undergoing cardiac resynchronization therapy. Am J Cardiol
2006;98:780-5.

82. THE ITERATIVE METHOD OF AV DELAY
OPTIMIZATION
 It begins by programming the CRT device in atrial synchronous V
pacing mode testing a series of AV intervals sequentially.
 This usually begins with an AV delay of 200 milliseconds, then
decreases in increments of 20-millisecond intervals to a minimum
AV delay as short as 60 milliseconds.
 The minimal AV delay that allows for adequate E and A wave
separation and termination of the A wave at approximately 40 to
60 milliseconds before the onset of the QRS would be
considered the optimal AV delay, and usually corresponds with a
stage I diastolic filling pattern.

83. AV DELAY OPTIMIZATION……..
 Technical features include positioning the pulsed
wave sample volume deeper toward the left atrium
(as opposed to the standard position at the mitral
leaflet tips) to optimize detection of the mitral valve
closure click, preparing settings of high sweep
speeds and low filters, and inputting the ECG signal
from the device directly to the ultrasound system, if
possible.

85. AV DELAY OPTIMIZATION……….
 A variation on the iterative method for AV optimization
uses transaortic Doppler velocities as a surrogate for
stroke volume.
 The optimal sensed and paced AV delay is determined
by the maximum aortic time-velocity integral value at 6
selected paced and sensed AV delays.
 A typical protocol will include measurements at AV
delays of 60, 80, 100, 120, 140, and 160 milliseconds,
with each paced and sensed AV delay setting separated
by a rest period of at least 10 to 15 beats.

86. CONCLUSION
 Good quality ECG with a stable baseline and clear delineation of
the onset of QRS complex is an essential requirement for
accurate measurement of time periods.
 Choose an ectopic free sequence and acquire at least 3-5 beats
with breath held in expiration.
 For TDI analysis, a sweep speed of 50-100 is recommended to
improve temporal resolution.
 Tissue Doppler analysis is highly angle dependent and
misaligned images produce velocity curves consisting of not only
the longitudinal but also the radial velocities. The sample volume
should be as parallel as possible to the incident beam.

87. CONCLUSION
 While analyzing color TDI data, the region-of-interest should be
moved within the myocardial segment to obtain the most
reproducible velocity curve with minimum artifacts.
 If more than one systolic peak is obtained in the tissue velocity
curve, the most reproducible peak of maximum amplitude should
be used for analysis. If two or more peaks have same amplitude,
the earlier peak should be taken into consideration.
 For 3D imaging, optimum gain settings with clear delineation of
the endocardial border, especially at the apex should be ensured.

88. CONCLUSION
 A complete echocardiographic study along with quantitation of
mitral regurgitation should always be performed in all cases.
 Right ventricular systolic function should also be assessed
routinely during dyssynchrony analysis and the findings
should be reported.
 No single parameter is predictive and there is no standard
recommended approach. Hence, all the parameters possible
depending on the laboratory and expertise should be
evaluated.

89. CONCLUSION
 The real value of these novel technologies remains to be determined
in randomized trials
 Several imaging techniques were evaluated (magnetic resonance
imaging, speckle tracking echocardiography, strain imaging, nuclear
imaging) and yielded several parameters of LV mechanical
dyssynchrony that have demonstrated to be independent
determinants of CRT response and long-term outcome in several
observational studies.

90. Everything should be made
as simple as possible, but
not simpler.
—Albert Einstein
THANKS