La selezione dei pazienti candidati alla Terapia Resincronizzante Cardiaca

M Cristina Porciani

Firenze

“Incontri Pitagorici di Cardiologia 2010”“Πυθαγόρειοι κάνουμε συναντήσεις καρδιολογίας” VIIIa Edizione

It has been well established that CRT is able to improve clinical and hemodinamic parameters in patients with heart failure and LBBB

McAlister FA et al, Ann Intern Med. 2004;.

CRT reduces HF hospitalizations

McAlister FA et al, Ann Intern Med. 2004;.

CRT improves quality of life

Cleland JGF et al NEJM 2005

CRT reduces mortality

CRT reverses LV remodeling

tSutton MG Circulation 2003

Reverse remodeling induced by CRT

Baseline

3 months

6months

CRT

1Circulation 2002

Biventricular Stimulation in Patients With Medically Refractory Heart Failure NYHA III-IV, Idiopathic or Ischemic Cardiomyopathy, QRS 120 ms, and EF 35%

Guidelines of ACC/AHA (2009)

RATIONALE OF CRT

LBBB

discordinate contraction

ventricular dysfunction

Electrical asinchrony Mechanical asynchrony

Lecoq G et al Eur Heart J 2005

Reduction of QRS duration occurs only in responders

29,5

57,1

71,1

0

10

20

30

40

50

60

70

80

<120 ms >120<150 ms >150 ms

QRS duration

Intraventricular dyssynchrony

%

Ghio S et al Eur Heart J 2004;25:571-578

Echocardiographic Data Before and After Cardiac Resynchronization Therapy

Achilli A et al JACC 2003

QRS > 120ms QRS< 120ms

Leclerq C et al Circulation 2002

Electrical epicardial activation map of whole heart for 3 pacing modes

Mechanical Resynchronization Does Not Require Electrical Synchrony in the Dilated Failing Heart With Left Bundle-Branch Block

Leclerq C et al Circulation 2002

Mechanical LV activation map of whole heart for 3 pacing modes

Mechanical Resynchronization Does Not Require Electrical Synchrony in the Dilated Failing Heart With Left Bundle-Branch Block

• it appears that

Mechanical rather than electrical synchronyseems most important for functional improvement with CRT

Interventricular asynchrony

TDI is useful in recording the chronology and the entity of the velocity curves of miocardium segments

Ts-SD Cut-off 33ms the Standard Deviation of the 6 basal and the 6 mid LV segmental Ts as systolic asynchrony parameter

Ts

septal to lateral delay

cut-off 60 ms

Bax et al. AM J Cardiol 2003;92:1238-40

Yu et al. JACC 2005; 45:677-84.

TSI (Tissue Synchronization Imaging)

No single measure of mechanical dyssynchrony may be recommended to improve pt selection forCRT

Methodology to determine mechanical dyssynchronyneeds further elaboration

QRS remains the selection criterium of dyssynchrony to identify for CRT

Circulation 2008

Results of the PROSPECT study

from the direct assessment of mechanical dyssynchrony , attention again shifted toward QRS

From the initial focus on electrical markers, interest shifted toward a more direct assessment of mechanical dyssynchrony by means of tissue Doppler imaging (TDI).

Porciani et al Echocardiography 2010

Electrical asynchrony + - + Mechanical asynchrony - + +

Porciani et al Echocardiography 2010

Since it is electrical activation that produces myocardial contraction that in turn is necessary for cardiac movement,why would they be any different?

The question is

►Problems with measuring electrical ayncrony

►Electromechanical interaction

►Complex nature of electrical and mechanical aynchrony

The answer should be

Problems with measuring electrical synchrony

Xiao Br Heart J 1994

Signal averaged electrocardiography detects potentials too low to appear on thestandard 12 lead electrocardiogram

Di Donato et al Circulation 2004

Surgical Ventricular Restoration Improves Mechanical Intraventricular Dyssynchrony in Ischemic Cardiomyopathy

Narrow QRS

Di Donato et al Circulation 2004

Surgical Ventricular Restoration Improves Mechanical Intraventricular Dyssynchrony in Ischemic Cardiomyopathy

Narrow QRS

Tournoux F. JCE, 2007

Concordance Between Mechanical and Electrical Dyssynchronyin Heart Failure Patients: A Function of the Underlying Cardiomyopathy?

What’s about mechanichal dyssynchrony?

Henein MY Heart 1999

Longitudinal asynchrony (TDI)

Radial asynchrony (Speckle-tracking radial strain)

Gorcsan J. JACC 2007

Combined Longitudinal and Radial Dyssynchrony Predicts Ventricular Response After Resynchronization Therapy

)

Gorcsan J. JACC 2007

Porciani et al PACE 2008

RV ejection RV filling

LV ejection LV filling

RV ejection RV filling

LV ejection LV filling

IVCT IVRT

IVCT IVRT

Normal

LBBB

a – bR-R

Total isovolumic Time Index

Myocardial Performance Index (MPI)

Porciani et al J Card Med 2010

Porciani et al J Card Med 2010

Porciani et al J Card Med 2010

CONCLUSIONS

Which is the best?