Ο ΡOΛΟΣ ΤΗΣ ΑΠΕΙΚOΝΙΣΗΣ ΣΤΗΝ ΗΛΕΚΤΡΟΦΥΣΙΟΛΟΓIΑ - ΥΠΟΣΤΡΩΜΑ ΚΟΛΠΟΙ ΩΤΙΑ ΑΞΙΟΛΟΓΗΣΗ ΟΥΛΗΣ

Transcription

1 Ο ΡOΛΟΣ ΤΗΣ ΑΠΕΙΚOΝΙΣΗΣ ΣΤΗΝ ΗΛΕΚΤΡΟΦΥΣΙΟΛΟΓIΑ - ΥΠΟΣΤΡΩΜΑ ΚΟΛΠΟΙ ΩΤΙΑ ΑΞΙΟΛΟΓΗΣΗ ΟΥΛΗΣ Κώστας Παπαδόπουλος, Επιμ. Α Καρδιολογίας, Νοσοκομείο Ερυθρός Σταυρός

2 ATRIA ANATOMY Complex anatomy Best knowledge essential for a safe and effective EPS procedure Left atrial imaging may facilitate EPS (ablation) by 1. providing a detailed anatomical description of the PVs and LA preprocedurally, 2. assisting in the detection of postprocedural complications. Ho SY, et al. Circ Arrhythm Electrophysiol 2012;5: Veinot JP, et al.. Circulation 1997;96:

3 K Boudoulas, I.A Paraskevaidis,H.Boudoulas, F.Triposkiadis. Cardiology 2014;129:1 17 ATRIA - FUNCTION PHASES RESERVOIR: LV systole, IVRT DETERMINANTS LA properties (relaxation and stiffness), RVSP, LV contraction CONDUIT-PASSIVE EMPTYING: LV early diastole (V-loop) PUMP-ACTIVE EMPTYING: LV end-diastole (A-loop) LV relaxation, LV early diastolic pressure LV compliance, LV end-diastolic pressure, LA contractility

4 ATRIAL FIBROSIS Collagen deposition, most commonly as a reparative process Convergent pathological end point in a variety of settings (Age-related, Valvular Disease, Hypertension, Ischemia, fibrotic atrial cardiomyopathy ) Multifactorial processes / interactions among neurohormonal and cellular mediators. Atria seem to be more sensitive than ventricles Normal Fibrotic Burstein B, et al. J Am Coll Cardiol 2008;51:802 9 Everett TH, et al. Am J Physiol Heart Circ Physiol 2006;291:H Nattel S, Opie LH. Lancet 2006;367:

5 ATRIAL FIBROSIS ATRIAL FIBRILATION ATRIAL FIBROSIS Structural, functional and electrical remodeling of the LA Substrate of AF Favors the generation and persistence of the arrhythmia The presence of pre-ablation fibrosis can be used to identify patients likely to develop recurrent atrial fibrillation postablation ATRIAL FIBRILATION Structural and functional remodeling of the LA Disorganization of myocyte architecture / Myolysis Imbalance in collagen synthesis and degradation Deposition of fibrillar collagen / expansion of the extracellular matrix Akoum N, et al. J Cardiovasc Electrophysiol 2013;24: Burstein B, et al. J Am Coll Cardiol 2008;51: Calkins H, et al. Europace (2012) 14, Tan, Koutsogeorgis, Grapsa, Papadopoulos, Katsivas, Nihoyannopoulos. Eur J Clin Invest 2014;44:872 82

6 DETECTION OF ATRIAL FIBROSIS INVASIVE (ELECTROPHYSIOLOGICAL) APPROACH NONINVASIVE (IMAGING) METHODS

7 INVASIVE (ELECTROPHYSIOLOGICAL) APPROACH ELECTROANATOMIC MAPPING Effective way of identifying areas of fibrosis using differences in voltage electrograms Atrial fibrosis: slower and more organized electrical activity but with lower voltage than healthy atrial areas Dense fibrosis: Bipolar voltage <0.1 mv Low voltage in EAM matches delayed enhancement areas with CMR in some studies Invasive nature limits EAM clinical application Ling, et al. Heart Rhythm. 2015;12: Jais, et al. Circulation. 2000;101: Tan, Koutsogeorgis, Grapsa, Papadopoulos, Katsivas, Nihoyannopoulos. Eur J Clin Invest 2014;44:

8 Scar evaluated by EAM before ablation. Patients with LAS have a significantly increased incidence of late AF recurrence compared with patients without LAS Verma A, et al. J Am Coll Cardiol 2005;45:285 92

9 NONINVASIVE (IMAGING) METHODS ECHOCARDIOGRAPHY MULTISLICE COMPUTED TOMOGRAPHY CARDIAC MAGNETIC RESONANCE

10 Lang RM, et al. Eur Heart J Cardiovasc Imaging 2015;16: Morava V, et al. JACC Cardiovasc Imaging. 2012;5: Blume G, et al. Eur J Echocardiogr 2011;12: ECHOCARDIOGRAPHY ATRIAL SIZE -LA and RA biplane volume, indexed by BSA, is the method currently recommended. -Normal: LA volume <34 ml/m 2 / RA volume < 30 ml/m 2 - LA enlargement the first detectable anatomical change before the onset of atrial fibrosis ATRIAL FUNCTION -Combination of LA vol. measurements: LA reservoir, conduit and contractile function -Speckle Tracking (2D/3D): LA reservoir, conduit and contractile function ASSOCIATED STRUCTURAL HEART DISEASE Valvular disease, left ventricular hypertrophy, and ventricular dysfunction

11 Lang RM, et al. Eur Heart J Cardiovasc Imaging 2015;16: Hoit BD. J Am Coll Cardiol.2014;63: Hirose T, et al. Eur Heart J Cardiovasc Imaging. 2012;13: Paraskevaidis, F Panou, C Papadopoulos. Heart 2009;95; SPECKLE TRACKING Myocardial deformation Atrial reservoir, conduit and contractile function Global and regional atrial contraction and relaxation GLS > 42% in healthy subjects Independently of the. angle and rotation / Less dependent on load Reduced atrial deformation in fibrosis Early and noninvasive marker of the amount of atrial wall fibrosis

12 In patients with severe MR referred for cardiac surgery, impairment of LA longitudinal deformation, as assessed by the global PALS, correlated strongly with the extent of LA fibrosis and remodeling Cameli Μ, et al. Am J Cardiol 2013;111:595e601

13 LA STRAIN AND STRAIN RATE IN PTS WITH PAROXYSMAL AND PERSISTENT AF. RELATIONSHIP TO LA REMODELING DETECTED BY DE-MRI LA strain and strain rate inversely correlated to LA wall fibrosis (as detected by DE MRI) The left atrial lateral wall strain may be used as a surrogate measure of left atrial wall fibrosis Kuppahally SS, et al. Circ Cardiovasc Imaging 2010;3:231 9.

14 LIMITATIONS Atrial wall significantly thinner than the LV Located in the far field of the ultrasound beam More difficult to trace and track accurately Image resolution frequently worse than the ventricle No validated cut off values for atrial fibrosis Strain imaging requires significant expertise, training Moderate interobserver and intraobserver variability All the echocardiographic approaches do not provide direct visualization of the fibrosis but are still limited to detecting the secondary effects of atrial wall fibrosis. Tan, Koutsogeorgis, Grapsa, Papadopoulos, Katsivas, Nihoyannopoulos. Eur J Clin Invest 2014;44:872 82

15 MULTISLICE COMPUTED TOMOGRAPHY Images with significantly better resolution compared with Echo Accurate quantification of atrial dimensions, volume and wall thickness Compared to CMRI, CT still does not provide sufficient resolution to visualize and quantify atrial fibrosis Fusion imaging which combine computed tomography datasets with data from other modalities, may be able to visualize fibrosis EAM CE-MDCT Ling, et al. Heart Rhythm. 2015;12:

16 CARDIAC MRI Imaging modality with sufficient high temporal and spatial resolution to image the left atrium successfully Delayed enhancement MRI (DE- MRI): Useful in localizing and quantifying diffuse global and regional atrial fibrosis Oakes RS, et al. Circulation. 2009;119: McGann CJ, et al. J Am Coll Cardiol. 2008; 52: Peters DC, et al.radiology. 2007; 243:

17 Good qualitative and quantitative relationship between electroanatomic mapping representations of ablation locations and scar with delayed enhancement CMR (20% of CARTO ablation sites no visible corresponding LGE) Taclas JE, et al. Heart Rhythm 2010;7:

18 ASSOCIATION OF LEFT ATRIAL FIBROSIS DETECTED BY DELAYED ENHANCEMENT MAGNETIC RESONANCE IMAGING AND THE RISK OF STROKE IN PATIENTS WITH ATRIAL FIBRILLATION Relationship of LA Structural Remodeling / Fibrosis and Stroke and CHADS 2 score. Daccarett M, et al. J Am Coll Cardiol 2011;57:831 8.

19 Utah stage 1 or minimal fibrosis Utah stage 2 or mild fibrosis Utah stage 3 or moderate fibrosis Utah stage 4 or extensive fibrosis <5% enhancement 5 20% enhancement 20 35% enhancement >35% enhancement Classification system for left atrial fibrosis Mahnkopf C, et al. Heart Rhythm 2010;7: Vergara GR, et al. J Cardiovasc Electrophysiol 2011; 22: Akoum N, et al. J Cardiovasc Electrophysiol. 2011;22:16 22

20 CMRI IN ATRIAL FIBRILLATION A. PRE-ABLATION FIBROSIS B. ABLATION-INDUCED SCARRING

21 A. PRE-ABLATION FIBROSIS Recurrence in groups Utah I to IV Comparison of recurrence rate in patients with lone AF and non lone AF Mahnkopf C, et al. Heart Rhythm. 2010;7:

22 ASSOCIATION OF ATRIAL TISSUE FIBROSIS IDENTIFIED BY 3D-DE-MRI AND AF CATHETER ABLATION THE DECAAF, MULTICENTER, PROSPECTIVE STUDY Among patients with AF undergoing catheter ablation, atrial fibrosis estimated by DE-MRI was independently associated with likelihood of recurrent arrhythmia Each 1% increase in fibrosis was associated with a 6% increased risk of recurrence Exclusion of 17.3% of pts of the initial cohort attributed to poor quality of DE-MR images Marrouche NF, et al. JAMA. 2014;311:

23 ATRIAL FIBROSIS QUANTIFIED USING LATE GADOLINIUM ENHANCEMENT MRI IS ASSOCIATED WITH SINUS NODE DYSFUNCTION REQUIRING PACEMAKER IMPLANT ROC analysis for predictors of pacemaker implantation. Advanced atrial fibrosis is significantly associated with pacemaker implantation. Akoum, et al. J Cardiovasc Electrophysiol. 2012;23:44 50

24 B. ABLATION-INDUCED SCARRING High-spatial-resolution delayed enhancement MR imaging allows noninvasive identification of scar induced by RF ablation following isolation therapy of the PV. Peters D et al, Radiology 2007;243:690-5

25 RECURRENCE OF ATRIAL FIBRILLATION CORRELATES WITH EXTENT OF POSTPROCEDURAL LATE GADOLINIUM ENHANCEMENT: A PILOT STUDY Among patients undergoing PV isolation, AF recurrence during the first year is associated with a lesser degree of PV and LA scarring on 3D LGE CMR. This finding was significant for RIPV scar, and may have implications for the procedural technique used in PV isolation. Peters D. et al. JACC Cardiovasc Imaging. 2009;2:

26 DARK REGIONS OF NO-REFLOW ON LATE GADOLINIUM ENHANCEMENT MAGNETIC RESONANCE IMAGING RESULT IN SCAR FORMATION AFTER ATRIAL FIBRILLATION ABLATION McGann C, et al. J Am Coll Cardiol. 2011;58:

27 CMR-GUIDED APPROACH TO LOCALIZE AND ABLATE GAPS IN REPEAT AF ABLATION PROCEDURE. In pts with AF recurrence, gaps in ablation lines are one of he main mechanisms of pulmonary vein reconnection. DE-CMR can locate these gaps and guide the second ablation procedure Bisbal F, et al. JACC Cardiovasc Imaging. 2014;7:

28 LIMITATIONS Detection of fibrosis by DGE lacks validation and requires further development and characterization Complex geometry / Smaller thickness of the LA Nearby enhancing structures such as aortic wall and valves. Claustrophobia Pacemaker Specialized technical expertise requirement Relatively high cost Karim R, et al. J Cardiovasc Magn Reson. 2013;15:105.

29 CONCLUSIONS Atrial fibrosis is a marker of atrial remodeling, contribute to electrical and structural changes within the atria predisposing to AF and vice versa ECHO / CT detect the secondary effects of atrial wall fibrosis (changes in atrial dimensions or function) CMRI the most promising NICVI in the detection of atrial fibrosis Studies are needed to evaluate the usefulness of NICVI guidance during the ablation procedure in humans NICVI: not yet a practical clinically applicable diagnostic tool for AF.