AF Ablation: How has the Technique and Technology

developed?Professeur Dipen ShahResponsable de l’Unité d’électrophysiologie,

Hopital Cantonal de Geneve,Geneve7th International Congress of Egyptian Cardiac Rhythm Association

15th-17th December 2010, Cairo

Architecture of the junction between pulmonary veins and the left atrium: lessons for radiofrequency ablation

25 year Male

Right Left

60y Male 60y Male 80y Female

Left upper

Ho SY et al, Heart 2001

Isthmus between veins at veno-atrial junction

Left upper

Left upper

Left lower

Left lower

Left lower

Common vein

PV Ablation Options

• Sequential point by point ablation

• Simple• Individual optimisation of

lesion delivery possible• Obligatorily time consuming• Finite irreducible rate of gap

occurrence• Circular lesion making

devices• Unfamiliar, more complex

design• Difficult to optimise contact/to

generate consistent lesions• Still do not achieve rapid,

one-shot isolation

Zheng et al, Journal of Interventional Cardiac Electrophysiology 5, 401–410, 2001

Linear Ablation Technologies

PV ablation times: segmental PVI: 35+15 min Hocini et al. and CPVA:37+11 min Oral et al. PVAC: Boersma et al. 27+7 min, & Scharf et al. 32+12 min

Multi-electrode PVAC • Incomplete circular form resulting in

suboptimal circular mapping• Combination of bipolar and unipolar RF difficult

to titrate• Noise does not allow electrogram monitoring

during RF• Uniform contact essential for bipolar RF

efficacy but unknown• No irrigation: uncertain protection from

char/coagulum• Ablation times similar to segmental PVI: no

single shot ablation

Cryoballoon AblationPre-Cryo Post-Cryo

LSPV Location of conduction recovery at redoImage courtesy V. Reddy

Cryo-Balloon

• Cryo-ablation in circulating blood: time consuming and probably smaller lesions

• PV anatomy oval not circular: single-shot ablation not frequent

• Inferior PVs difficult to isolate

• Significant risk of phrenic palsy

• No immunity from esophageal damage

Pacing Catheter in SVC

Cryoballoon Catheter at

RSPV ostium

Image courtesy V. Reddy

Visually-Guided Ablation

Aiming Beam

“Static” Blood in LSPV

LIPVLAA

In Vivo Visually-Guided A.Flutter Ablation

V.Reddy / P.Neuzil (manuscript in preparation)

Contact Sensing

0

500

1000

1500

2000

Contact Force (g)

2 10 20 30 40 2 10 20 30 40

500

1000

1500

2000

445

683

906

1186

1542

271

431

632773

1052

p <0.01 p <0.01

30W 50W

(mm3)

Lesion Volume vs. Contact Force

Contact Force (g)

Incidence of Steam Pop

(%)

20

40

60

80

100

2 10 20 30 40

0/10

5/10

6/10

7/10

8/10

50W p =0.0026

0

20

40

60

80

100

2 10 20 30 40

0/10 0/10 0/10 0/10

3/10

30W p =0.031

(%)

Yokoyama K, Nakagawa H, Shah D et alCirc Arrhythmia EP 2008

12%

Source: K-H Kuck, presentation Boston AF 2010

12 % of ablations done with low contact forces (< 5 g)

0%

5%

10%

15%

20%

25%

30%

35%

%ag

e o

f ab

lati

on

s d

on

e w

ith

co

nta

ct f

orc

e <

5g

12%

RIGHT PVs

Septal Sup.

Septal Inf. Roof Middle Inferior Post.

Sup. Post. Inf.

Low forces 15% 12% 3% 13% 23% 12% 11%

LEFT PVs

Post. Sup. Post. Inf. Roof Middle Inferior Ant. Sup. Ant. Inf.

8% 4% 7% 23% 7% 21% 32%

RPV

Post

LPV

An

terS

ep

tal

Roof

Inf

32%

Sheath assisted Perforation

0

50

100

150

200

250

300

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41

RV without sheath RV with sheath

RV **

0

100

200

300

400

500

600

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101

LV without sheath LV with sheath

LVw/o sheath

with sheath

w/o sheath

with sheath

Peak Df/dt: LV perforation

LV perforation time:

0.8±0.5s with sheath vs 3.2±3 s w/o, p<0.0001

gra

ms

time time

736 ± 368 g/sec

239±178 g/sec

p = 0.0013

Shah D et al, Europace 2010

Perforating Force thru’ RF lesions

172±79g

300±116g

p<0.002

n= 23 n= 21

Shah D et al, Europace 2010

Remote Navigation Systems

• Magnetic Navigation: Fixed Magnets (Stereotaxis)• Magnetic Navigation: Electro-Magnets (Magnetecs)• Robotic Navigation (Hansen Medical)

Fixed Magnetic Nav Robotic Nav

Electro-Magnetic Nav

Arya et al, Europace 2010 e-pub

robotic arm

Sensei™ Robotic Catheter System

3D mouse

Electromechanic Navigation

• 34 of 40 pts off anti-arrhythmic drugs and „free from atrial arrhythmia“ 85%

• 5 pts still on anti-arrhythmic medication

• 2 pts with perforations/tamponade

Atrial fibrillation ablation

Saliba et al. JACC Vol. 51, No. 25, 2008:2407–11

Wazni et al, JCE 2009• 71 patients undergoing PV antral

isolation• 5 vascular complications• 3 tamponade• 5 severe PV stenosis• 1 gastroparesis

• 4/4 pts with esophageal ulceration at endoscopy on the post-ablation day

• 1/4 pts developed esophageal fistula formation necessitating stenting

Kuck KH, EHRA-Webinar AF ablation, March 2009

Electro-mechanical Navigation

• Point by point mapping and ablation: no reduction in procedure time

• Extra –stiff sheath and poor contact force monitoring: higher risk of traumatic perforation and other complications

• Single catheter control only• AF ablation poorly suited to automated,

fully robotic procedure

Technology for AF Ablation

• New technology should simplify ablation

• Shorten the procedure by reducing ablation times

• Provide rapid and reliable endpoint verification

• Result in durable, non-proarrhythmic lines of isolation

• Should not increase complication risks

Current standard of reference…