Catheter ablation of atrial macro re-entrant Tachycardia - How to use 3D entrainment mapping - M. Esato, Y. Chun, G. Hindricks Kyoto Ijinkai Takeda Hosptial, Department of Arrhythmia, Japan Kyoto Koseikai Takeda Hospital, Arrhythmia Care Center, Japan University of Leipzig, Heart Center, Germany
Entrainment / Post Pacing Interval 300 300 PPI 320 320 S 300 S 300 S 200ms X Re-entrant circuit PPI=X+TCL+X=2X+TCL Re-entrant circuit PPI=2X+TCL=TCL
Background An accurate understanding of the anatomical location of the re-entrant pathway in macro re-entrant atrial tachycardia (MRT) is crucial for curative ablation of the arrhythmia. Electrically diseased atria with scarred areas, discontinuous ablation lines, subsequent multiple conduction delay and related difficulties in allocation for the appropriate local activation time limit the ability to understand the true nature of the re-entrant circuit.
Purpose Evaluation of a novel approach for mapping and ablation of MRT based on direct visualization of the re-entrant circuit through 3D colour coded entrainment mapping using PPI and subsequent strategic ablation lesion placement.
Concept of color coded PPI Mapping A ABL p 300 330 330 d RVA PPI MRTCL=0 B ABL p 300 370 330 PA PA d RVA PPI MRTCL=40 C D ABL p 300 435 330 ABL p 300 485 330 d RVA PPI MRTCL=105 d RVA PPI MRTCL=155 LPO Esato M, Hindricks G, Piorkowski C, et al. Heart Rhythm 2009.
Selected lesion line concepts MRT circuit around PV ostium perimitral through LA roof around LA appendage (LAA) within the septum CTI dependent around right atrial scar right atrial upper loop within the Ablation line concept wide circumferential PV isolation mitral isthmus line LA roof line circumferential LAA ablation 1) left atrial septal line (MA to right PVs) 2) right atrial septal line ( to ) CTI line connection between scar and 1)connection between TA and 2)connection between and line within the ; coronary sinus, CTI; cavotricuspid isthmus, ; inferior vena cava, LA; Left atrium, MA; mitral annulus, ; superior vena cava.
Patient characteristics Enrolled Pts 30 Age 60 +/- 12 (63% male) Organic heart disease 15 (50%) CHD 5 Valvular 6 HCM 1 DCM 2 ASD 2 Cardiovascular op. 11 (37%) CABG 4 MVR 4 TVR 1 Patch closure 2 PM/ICD 5 (17%) Lone AF 6 (20%) LVEF (%) 57 +/ - 12 LA (mm) 46 +/ - 5 Previous pulmonary vein (PV) isolation 23 (77%)
Method (I) Initial entrainment : high right atrium (HRA), cavotricuspid isthmus (CTI), and distal/proximal area of coronary sinus () differentiate the right or left atrial (LA) origin of MRT. Patients (Pts) with sinus rhythm : Induction of the clinicallly documented MRT with burst and / or extra atrial stimuli. Mapping with CARTO : Reconstruction of 3D chamber anatomy together with sequential mapping and PPI point acquisition. Mapping with NavX : Using an integrated 3D CT image without chamber surface reconstruction.
Method () Entrainment pacing : -30ms of MRT cycle length (C.L.) with an output of 7.5V/1.5ms was attempted. Tagging method : PPI - MRT C.L. was calculated and stored together with the 3D anatomical position on the EAM in a colour coded fashion. Catheter ablation : a) 3.5mm irrigated tip catheter. b) Strategic linear lesion concepts were deployed to terminate MRT. (no strategic achievements finding slow conduction area and/or the critical isthmus of MRT!) c) Termination of MRT during RF delivery and non-inducibility of any MRT as a procedural endpoint. (additional circumferential PV isolation; Case with prior-failed.)
CTI dependent MRT Ablation line concept : CTI line 130 ms 130 ms I I avr avl RAA TA 4 ms TA 4 ms V2 LAO LL V3 V4 130 ms 130 ms V6 7-8 5-6 RAA 3-4 4 ms 4 ms 1-2 PA RPO
Perimitral MRT Ablation line concept : mitral isthmus line I I LAA LAA avr avl MA MA RLPV V2 V3 LAO LL V4 LAA V6 7-8 LAA 5-6 3-4 RLPV RLPV 1-2 LPO RAO
MRT thorough the LA roof Ablation line concept :LA roof line I I LAA LAA avr avl RLPV MA MA V2 V3 LAO LL V4 LAA LAA V6 7-8 5-6 3-4 RLPV RLPV 1-2 PA RL
MRT from within the Ablation line concept :line within the 400 ms 400 ms I I avr avl V2 TA MA 1 ms LA RA RLPV 1 ms V3 LAO 400 ms LPO 400 ms V4 V6 7-8 5-6 3-4 1-2 PA LA RLPV RA 1 ms RAO TA MA 1 ms
MRT around the Ablation line concept :connection between superior TA and connection between and I I avr avl TA V2 V3 LAO LL V4 V6 7-8 5-6 TA 3-4 1-2 PA RAO
Results (I) MRT C.L. (ms) 327 +/- 74 (range 230-460) Entrainment (PPI) points 35 +/- 17 (range 10-77) 2 2 2 1 6 4 12 12 28 6 6 6 9 MRT origin (n=48) LA (58%) RA (25%) Septum (13%) (4%) MRT mechanism (n=48) Perimitral (25%) Around LAA (8%) CTI dependent (19%) RA scar related (4%) LA roof (13%) Within (4%) Around PV (13%) Around (2%) Within septum (13%)
Catheter ablation : Results () All 48 MRTs were successfully terminated (100% termination). All 30 Pts remained non-inducible of any MRT. 3 of 6 (50%) septal MRTs required both left and right septal lesion line for MRT termination. 5 of 12 (42%) perimitral MRTs required epicardial completion within the for MRT termination. Clinical outcome and follow-up : 266 + / - 61 days (range 165-411 days). 3 (10%) Pts documented recurrences of MRT. Patient MRT mechanism initial second 1 perimitral / CTI perimitral 2 LAA LAA 3 within around PV (RPV)
Conclusions Colour coded 3D entrainment mapping is a new method for direct visualization of the entire re-entrant circuit and the selection of a strategic linear ablation line at an anatomically convenient location, not necessarily targeting the area of slow conduction and/or critical isthmus of the re-entrant circuit. The approach is feasible, provides a detailed understanding on the location of the re-entrant circuit and resulted in an excellent rate of tachycardia termination with a satisfying clinical efficacy.