Assessment of a CRT candidate by Echo, step by step

1. “
Echocardiographic Parameters in CRT
Patients Selection
1

2. Dr. Naveen Sheikh
Asst Professor, Cardiology,
BSMMU
Chairperson

3. Dr. Azim Anwar
Phase B Resident,
Cardiology, BSMMU
Presenter

4. What is CRT ?
Lead placements in CRT & VIDEO
Why CRT is needed ? (Guidelines)
What is dyssynchrony ? & VIDEO
Why dyssynchrony should be asessed by Echocardiography ?
Echocardiographic parameter for CRT candidates
How CRT corrects dyssynchrony ? & VIDEO
Echo in followup of post CRT patients

5. Limitations
• Echocardiographic findings of real patient
• CRT in AF
• CRT-P & CRT-D
• CRT Echocardiographic assessment by TDI &
Strain

7. What is CRT ?
Cardiac resynchronization therapy (CRT) is
 a modality of cardiac pacing
 used in patients with left ventricular (LV) systolic dysfunction
 and dyssynchronous ventricular activation
 that provides simultaneous or nearly simultaneous electrical
activation of the LV and right ventricle (RV) via stimulation of
the LV and RV

8. Continue. . .
• Cardiac resynchronization therapy (CRT) is a biventricular
pacemaker —— that sends electrical signals to both lower
chambers of the heart (right and left ventricles)

10. between the orifice of the inferior vena cava and the
atrioventricular opening

11. https://www.youtube.com/watch?v=FAGno7PZaQs

12. https://www.youtube.com/watch?v=t1lU4qfNw0I

13. www.escardio.org/guidelines
2021ESCGuidelines on cardiac pacing and cardiac resynchronization therapy
(European Heart Journal 2021– doi:10.1093/eurheartj/ehab364)
©ESC
Recommendations Class Level
LBBB QRS morphology
CRT is recommended for symptomatic patients with HF in SR with LVEF ≤35%,
QRS duration ≥150 ms, and LBBB QRS morphology despite OMT, in order to
improve symptoms and reduce morbidity and mortality.
I A
CRT should be considered for symptomatic patients with HF in SR with LVEF
≤35%, QRS duration 130–149 ms, and LBBB QRS morphology despite OMT, in
order to improve symptoms and reduce morbidity and mortality.
IIa B
Recommendations for cardiac resynchronization therapy in patients
in sinus rhythm (1)
CRT = cardiac resynchronization therapy; HF= heart failure; LBBB = left bundle branch block; LVEF= left ventricular ejection fraction; OMT = optimal medical therapy; SR = sinus rhythm.

14. www.escardio.org/guidelines
2021ESCGuidelines on cardiac pacing and cardiac resynchronization therapy
(European Heart Journal 2021– doi:10.1093/eurheartj/ehab364)
©ESC
Recommendations Class Level
Non-LBBB QRS morphology
CRT should be considered for symptomatic patients with HF in SR with LVEF
≤35%, QRS duration ≥150 ms, and non-LBBB QRS morphology despite OMT, in
order to improve symptoms and reduce morbidity.
IIa B
CRTmaybeconsideredforsymptomaticpatientswithHFinSRwithLVEF≤35%,
QRSduration130–149ms,andnon-LBBBQRSmorphologydespiteOMT,inorder
toimprovesymptomsandreducemorbidity.
IIb B
QRS duration
CRT is not indicated in patients with HF and QRS duration <130 ms without an
indication for RV pacing.
III A
Recommendations for cardiac resynchronization therapy in patients
in sinus rhythm (2)
CRT = cardiac resynchronization therapy; HF= heart failure; LBBB = left bundle branch block; LVEF= left ventricular ejection fraction; OMT = optimal medical therapy; SR = sinus rhythm.

15. What is Dyssynchrony ?
• Definition and evaluation of cardiac dyssynchrony are
still subject to debate.
• Cardiac dyssynchrony refers to deviations or
disturbance of the normal sequence of activation and
contraction between the atria and ventricles of
the heart.

16. How to detect dyssynchrony & why
echocardiography is needed ?
• QRS duration >120 ms on surface electrocardiogram (ECG), is
currently the only guideline-recommended dyssynchrony
parameter for patient selection for cardiac resynchronization
therapy
• 60-70% sensitivity

17. So What to Do ?
 In order to improve CRT success rate, a number echocardiographic
parameters have been proposed
 Echocardiographic assessment of CRT candidates comprises:
 evaluation of left ventricular global function (ejection fraction and
volumes)
 evaluation of left ventricular regional function (extent and localization of
infarct scar) and
 evaluation of cardiac dyssynchrony.

18. Atrioventricular Dyssynchrony
pulsed-wave Doppler recording of
transmitral flow. Diastolic filling
time (LVFT), defined as the sum of
E-wave and A-wave duration, is
divided by the RR interval duration
(Figure 1) to obtain a diastolic
filling ratio (LVFT/RR). Significant
atrioventricular dyssynchrony is
assumed if LVFT/RR is <40%.
Atrioventricular dyssynchrony has
limited predictive value for CRT
response.

19. Interventricular dyssynchrony
using conventional pulsed-wave
Doppler. The presence of inter-
ventricular dyssynchrony is indicated
by the difference of >40 ms
between left ventricular and right
ventricular pre-ejection time
(measured by pulsed-wave
Doppler). Left ventricular
electromechanical delay (pre-
ejection time) is determined as the
time from QRS onset to aortic flow
onset

21. Intraventricular Dyssynchrony
Conventional echocardiography
septal to posterior wall motion delay (cut-off >130 ms)
Septal to posterior wall
motion delay is assessed by
M-mode echocardiography
from parasternal short-axis
view at the papillary muscle
level. It is calculated as the
interval between the
maximal posterior
displacement of the septum
and the maximal
displacement of the left
posterior wall (Figure 5).
This method is not
applicable in patients with
previous septal or posterior
wall myocardial infarction.

22. left ventricular electromechanical delay
(cut-off >140 ms)
Left ventricular
electromechanical delay (pre-
ejection time) is determined
as the time from QRS onset
to aortic flow onset

23. Apical Rocking
• https://www.escardio.org/Education/Practice-Tools/EACVI-toolboxes/3D-
Echo/echo-parameters-in-crt-patients-selection

24. Septal Flash

25. Septal flash
Septal mitral annular Velocity by TDI

26. How CRT works ?
https://www.youtube.com/watch?v=FAGno7PZaQs

27. Assessment of CRT Response by ECHO
• the end-systolic volume reduction of ≥ 10-15%
after 3-6 months of device implantation
usually defines echocardiographic response to
CRT

28. THANK YOU
Any Questions ?