Overview of Atrial Flutter

Transcription

1 Overview of Atrial Flutter Samsung Medical Center Lee, Chang Hee

2 Atrial Flutter A macro-reentrant reentrant atrial arrhythmia that is very regular with rates typically between 240 and 350 bpm.

3 Demographics Incidence in general population times more common in males - risk increases 3.5 times in presence of heart failure - risk increases 1.9 times in presence of COPD 3. Granada J, et. al. Incidence and Predictors of Atrial Flutter in the General Population J Am Coll Cardiol Dec, 2000;36(7):2242-6

4 Classification of AFL Typical Atypical Macro reentry Type I Clockwise Usual Classical AFL Reverse flutter Counter clockwise Type II Type IC Isthmus dependent Antidromic Non Isthmus dependent Orthodromic

5 Proposed classification of AFL Recent NASPE(HRS) position paper proposed an open classification - AFL classification Typical AFL (CCW) Reverse Typical AFL (CW) Others 4. Saoudi, N. et. al. Classification of Atrial Flutter and Regular Tachycardia According to Electrophysiologic Mechanism and Anatomic Bases: A Statement from a Joint Expert Group from the Working Group of Arrhythmias of the European Society of Cardiology and the North American Society of Electrophysiology. JCE, volume 12, No. 7, pp July 2001.

6 Electrogram recognition of AFL Rate Atrial rate regular/stable * bpm P wave morphology - Saw tooth pattern - Typical AFL : Negative P in II, III and avf, Positive P in V1 - Reverse typical AFL : Positive P in II, III,aVf, Negative P in V1

7 Typical AFL III Avf II III Avf II Typical - CCW Reverse Typical - CW

8 Others AFL Non-isthmus dependant AFL : Atypical RA flutter

9 Typical AFL(CCW) / Reverse Typical AFL(CW)

10 Cardiac anatomy of AFL Typical AFL(CTI dependant)

11 Cardiac Anatomy TA ER/EV ISTHMUS Atrial Flutter is a reentrant tachycardia in which the reentrant circuit is contained in the right atrium. The reentrant circuit in Typical atrial flutter revolves around the tricuspid annulus (TA) and passes through t the isthmus in a counterclockwise direction. Reverse typical atrial flutter revolves ves around the tricuspid annulus in the clockwise direction. The isthmus is formed by the IVC and Eustachian ridge/vale (ER/EV) on one side and the TA on the other. Conduction during fast rates can not transverse the ER/EV.

12 Jose A Cabrera, MD-2007 HRS

13 Septal / Posterior isthmus

14 Variability of Trabeculated isthmus -Non-uniformity of the Posterior Isthmus highly variable trabeculated patterns found inferior to the Cs ostium as well as at the inferior rim of the Cs ostium within the flutter isthmus -Eustachian valve and ridge Waki, K. et.al. JCE Vol 11. No 1 January 2000 pg Nakagawa. H., et al., Role of the Tricuspid Annulus and the Eustachian Valve/Ridge on Atrial Flutter: Relevance to Catheter Ablation of the Septal Isthmus and a New Technique for Rapid Identification of Ablation Success.. Circulation. 1996;94:

15 Difficult isthmic AFL ablation

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17 Koch s s triangle and Septal / Posterior isthmus

18 Ablation of AFL Typical - Typical AFL (CCW) HIS SVC - Reverse Typical AFL (CW) IVC 1 ER CS 3 2 TV

19 Targets for Ablation of Typical AFL Type of flutter CTI-dependant Partial isthmus dependant Targets CTI from TV annulus to IVC TV annulus-er isthmus TV-CS ostium-er isthmus CS ostium to IVC

20 Catheter positions Catheter insertion & positioning(ii) - HRA : femoral access, Duodecapolar right atrium 을 circling 한다. (septal,, free wall cover) - CS : subclavian access, Decapolar(C 니, DAO,DAO-1) CS 는 left atrium 과 left ventiricle 사이의 AV sulcus 에 위치하므로이곳에위치한카테터로부터 atrium 과 ventricle 을쉽게 recording 할수있다. (bi-directional block 확인시 pacing 할수있다.) - RVA / RVOT : femoral access, Quadripolar right ventricle 의전극카테터는일반적으로 apex 에위치하 며 recording, pacing 하는데이용된다.(full EPS 경우 RVOT 으로이동하여검사를진행한다.) - HIS : His bundle 은 AV conduction 의대한정보를제공

21 Fluoroscopic positions RAO 35 LAO 45 DuoDec DuoDec HIS HIS CS CS RV RV

22 Fluoroscopic positions Jose A Cabrera, MD-2007 HRS

23 Orientation during RF Ablation LAO Atrial flutter ablation is anatomically guided along with electrogram verification of location between the: Tricuspid annulus (TA) and CS os (septal isthmus: 5 o'clock ) TA and inferior vena cava (IVC) (central isthmus: 6 o'clock) TA and IVC (infero( lateral isthmus : 7 o'clock)

24 Intracardiac Electrogram Recognition CCW mapping

25 Intracardiac Electrogram Recognition CW mapping

26 Note sequential activation along the leads of the blue mapping catheter. The yellow ablation catheter is placed in the isthmus between the tricuspid valve and the eustachian valve of the IVC.

27 AFL Ablation End Points Termination of clinical arrhythmia Inability to re-induce atrial flutter Complete Bi-directional block

28 During ablation - termination

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30 CS prox.. pacing after CTI Block LAO 45 - Confirmation of Bi-Directional block

31 LRA. pacing after CTI Block LAO 45 - Confirmation of Bi-Directional block

32 Methods of determining bidirectional isthmus block after ablation

33 - Methods : Point to point activation mapping along ablation line during PCS pacing post ablation - Measure : Interval between split components of isthmus electrogram(dp1-2)on ablation catheter - Definition of Complete Isthmus Block : DP Reference : Tada.JACC 2001;38:750~755

34 During ablation - CTI block(+)

35 - Methods : Pacing at sites(a,b,c and D)on both side of ablation line and record bipolar EGM activation times at points A,B,C and D pre post ablation -Measure : Conduction times among sites A,B,C and D - Definition of Complete Isthmus Block : Conduction times AD>BD and DA>CA after ablation - Reference : Chen.circulation 1999;100:

36 C B A D

37 - Methods : Unipolar EGM recording during PCS pacing pre- and post-ablation - Measure : Unipolar EGM polarity immediately lateral ablation line - Definition of Complete Isthmus Block : Loss of negative components and development of R or Rs pattern in unipolar EGM - Reference : Villacastin J.Circulation 2000;102:3080

38 Summary RF catheter ablation has become a first-line treatment for AFL, with almost uniform acute and chronic success and a low complication rate. The most effective approach is combined anatomically and electrophysiologically guided of the CTI. Procedure end point is Non-inducibility and Complete bidirectional block.

39 Currently, the use of a large-tip ablation catheter with high out-put RF generator or cooled tip ablation catheter with standard RF generator. Summary : cooled tip setting 30~40W, <50 C : 4m tip setting 40W, 60 C, : 8~10m tip setting 100W, 50~70 C

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