The California Heart Rhythm Symposium San Francisco - 2009

Mapping and RF Ablation of Sustained VT - Methods, Strategies, and Techniques • Mapping Systems

Epicardial Approaches for Ablation of VT:

– Electrograms based mapping – Electro anatomic based mapping – Simultaneous multi electrode mapping

• Mapping Strategies

When, Pitfalls, Perils

– During sinus rhythm – During VT – Trigger that initiates polymorphic VT

• Mapping Approaches Mauricio Scanavacca

– Endocardial (aortic retrograde / transeptal) – Epicardial (surgical / transvenous / percutaneous)

• Ablation Systems Heart Institute (InCor) - University of Sao Paulo Medical School - Brazil

Subendocardial myocardial fibers

– RF energy (4-mm / 8-mm / irrigated tip catheters) – Cryo, Ultra sound, Microwave and Laser energies

MI Related Scar - Endocardial RF Ablation -

SCAR

Sub epicardial fibers

Subepicardial myocardial fibers

Sub epicardial fibers

Stevenson – NASPE 2003

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Catheter Ablation of Recurrent Scar-Related Ventricular Tachycardia Using Electroanatomical Mapping and Irrigated Ablation Technology

Irrigated Radiofrequency Catheter Ablation Guided by Electroanatomic Mapping for Recurrent Ventricular Tachycardia After Myocardial Infarction

Results of the Prospective Multicenter Euro-VT-Study

The Multicenter Thermocool Ventricular Tachycardia Ablation Trial

JCE. 2009

Circulation. 2008

N = 231; post MI patients EF = 0.25 N of VT in 6 m = 11 (median) N of VT/ patient = 03 (median)

Electroanatomical Mapping

N = 63; post MI patients EF = 30+ 13% VT in 6 m = 1 – 380 (17median) N of VT/ patient = 03 (median)

Mappable VT = 31% Unmappable = 31% Both = 38% Acute success = 49% Hospital mortality = 3%

Electroanatomical Mapping

Incessant VT = 14 (22%) Unmappable

= 14 (22%) Irrigated Tip Catheter

Irrigated Tip Catheter

Acute success = 51 (81%) No mortality in the hospital

53% of patients were free of ICD Shocks in 6 months

VT recurrence in 12 months = 49%

Epicardial and endocardial mapping of ventricular tachycardia in patients with myocardial infarction

Epicardial and endocardial mapping of ventricular tachycardia in patients with myocardial infarction • Epicardial and endocardial isochronal maps maps;; of 47 VTs VTs;; 28 patients; patients; MI (inferior: (inferior: 14; anteroseptal: anteroseptal: 14)

• Epicardial and endocardial isochronal maps maps;; of 47 VTs; VTs; 28 patients patients;; MI (inferior (inferior:: 14; anteroseptal anteroseptal:: 14)

Five types of activation patterns •

•

Kaltenbrunner W et al. Circulation 1991.

Complete mapped circuits – A: subendocardial reentry circuits

07 VTs (15%)

– B: subepicardial reentry circuits

04VTs (9%)

Incompletely mapped circuits – C: Endo preceding the EPI breakthrough

25VTs (53%)

– D: EPI preceding the ENDO breakthrough

03 VTs (6%)

– E: EPI breakthrough suggesting deep septal reentry

08 VTs (17%)

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Chagas VT Epicardial Circuit

I

Epicardial and endocardial mapping of ventricular tachycardia in patients with myocardial infarction. Is the origin of the tachycardia always subendocardially localized?

II TV MV

V1

• Epicardial and endocardial isochronal maps maps;; of 47 VTs VTs;; 28 patients; patients; MI (inferior: (inferior: 14; anteroseptal: anteroseptal: 14)

VTs (%)

Patients (%)

1

A

V6

RF Epicardial Lesions

CS - p

2

V

• Left ventricular endocardial reentry substrates

68

100

• Subepicardial reentry substrates

15

25

• Deep septal layers

17

25

A

CS - d V

V

RV - p

V

RV - d

V

Epi - p

Kaltenbrunner W et al. Circulation 1991.

Epi - d

RF on

6.5 sec

200mm/s

- 105 ms

Epicardial RF Ablation

Effectiveness of Epicardial VT Ablation RV

Related to : • Prevalence and anatomical characteristics of the epicardial circuits in a given population

LV

• Epicardial barriers for epicardial ablation – Coronary vessels distribution – Fat tissue – Pericardial adhesions RF- 2

• Risks of pericardial puncture and contiguous tissue injury during RF ablation: RF- 1

– Coronary arteries, Phrenic nerve, Lung, Parietal Pericardium

GAP GAP

Heart Rhythm 2006

3

Monomorphic Ventricular Tachycardia InCor - São Paulo - Brazil (n: 59 598) 8)

Prevalence of Mappable Epicardial VTs in Structural Heart Disease - n: 257

100 • Idiopathic • Dilated Cardiomyopathy • Right Ventricular Dysplasia • Surgical: (Fallot; Batista’s) • Valvular Heart Disease • Hypertrophic Cardiomyopathy • Tumor

VT Etiology 130 - (22%)

Ischemic Nonischemic

194 - (32%)

Endocardial VT

Epicardial VT

76

72 63

%

50

37 28

24

274 - (46%)

Chagas 0

100

200

300

epi

epi

Post-MI*

Chagas

DCM

n: 60

n: 173

n: 24

epi

0

Patients

* inferior MI

Endocardial and Epicardial Ablation with regular 4mm catheter

Probabilidade estimada de sobrevida livre de eventos

-Recurrence in 257 patients -

Suggestive Findings of Epicardial VT

1,0 0,9 0,8

• Intracardiac recording • Absence of early endocardial activation site

0,7 0,6 0,5

endo + epi ablation

0,4 0,3

endo ablation only

0,2 0,1

• Diffuse area of earliest endocardial activation • Poor endocardial pace maps • Failed ablation at best endocardial sites

0,0 0

1

2

3

4

5

6

years

4

Epicardial and Endocardial Substrate Mapping in Chagas’ Heart Disease

Electrocardiographic Recognition of the Epicardial Origin of Ventricular Tachycardias

• PseudoPseudo-delta wave > 34 ms sensitivity 83%; specificity 95% Epicardial Mapping

Endocardial Mapping

RV

Epicardial Mapping

LV Epicardial Scar Related to VT

• Intrinsicoid deflection time in V2 > 84 ms sensitivity 87%; specificity 90%

• The shortest RS complex >121 ms sensitivity 76%; specificity 85%; Berruezo et al. Circulation. 2004

Epicardial Accesses for Epicardial Mapping Techniques – surgical

Epicardial Techniques in the EP Lab

Techniques – surgical

• Open chest

• Open chest

• Video thoracoscopy

• Thoracoscopy

– non surgical • coronary venous system • subxiphoid percutaneous

– non surgical • coronary venous system • subxyphoid percutaneous Xyphoid

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Subxhyphoid Access to the Pericardial Space

Subxhyphoid Access to the Pericardial Space

Subxhyphoid Access to the Pericardial Space

Subxyphoid Epicardial Approaches

A

B

Wire guide contrast

needle needle

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Subxyphoid Pericardial Approach - anterior access -

Subxyphoid Pericardial Approach - anterior access -

LA appendage LV Anterior Wall Apex Pericardium

Apex

RVOT Pericardium

RV Anterior Wall

Right laterar view of the Heart

Subxyphoid Pericardial Approach - posterior access -

Subxyphoid Pericardial Approach - posterior access -

RVOT

Pericardium RV Anterior Wall

Apex

Apex LV lateral Wall

Pericardium

Left laterar view of the Heart

7

Pericardial puncture with the Tuhoy needle

Introducing the sheath in the pericardial space

Guidewire insertion through the Tuhoy neeedle

Intrapericardial catheter positioning

8

Epicardial VT Ablation N = 373

Epicardial VT Ablation N = 373

Risks

Risks

• Pericardial puncture • Megacolon = 0 • Stomach = 0 • Liver = 0

• Pericardial bleeding

RAO

– “dry RV puncture = 5% – drained > 50cc = 10% – surgical correction = 0.8% • Intraperitonial bleeding = 0.3% megacolon

Hemopericardium

Saline Solution

Epicardial VT Ablation Reinfusion Bag

N = 373

Collecting Reservoir

Risks • Epicardial Ablation • Coronary artery Damage – Coronary artery spasm = 0 – Coronary occlusion = 0.3% Centrifuge

“Cell Saver”

Waste Bag

9

Effects of RF Pulses Delivered in the Vicinity of the Coronary Artery

Catheter Ablation of Ventricular Epicardial Tissue A comparison of Standard and Cooled-Tip Radiofrequency Energy

CA diameter: 0.8± 0.4 mm

Irrigated RF lesion

N Fat Power T°° Depth

Convencional RF lesion

Epicardial fat

Cooled -tip

Standard RF

4 mm

4 mm

47 2.6± 2.6±1 45W 40 40° °C 4.1± 4.1±2

33 3.1± 3.1±1 16W 69 69° °C NOT SEEN

CA diameter: 1.8 ± 0.8 mm

No occlusion Thrombosis

No lesion

d’Avila et al - Circulation - 2004

D’Avila-- PACE 2000; 25: 1488 D’Avila

During the procedure

Before the procedure

Epicardial VT ablation Coronary Vessel Relationship with the Target

Risk

safe

RV

CS

RV

Epicardial catheter

safe A

B

10

Epicardial VT ablation

Cryotermia vs. Radiofrequency Catheter Ablation within the Canine Coronary Sinus Close to the Left Circumflex Coronary Artery

Coronary Vessel Relationship with the Target

RF = 30 – 50 W, irrigated tip; Cryo: -700C for 4 min LAO OAE

ABL

CS

RF

RV VD

B

Cryo

II RF On DCS

Aoyama H et al. JCE 2005

Epicardial VT Ablation N = 373

Phrenic Nerves

• Risks • Phrenic nerve damage = 3 (0.8%) • Transitory = 1 • Permanent = 2

Quintana et al. JCE. 2005;16:309

11

Epicardial Ablation Close to the Phrenic Nerve

Air Injection into the Pericardial Space to Prevent Phrenic Nerve Injury

CS

LAO

Epicardial Phrenic Stimulation

Buch et al. Heart Rhythm 2007

Jais P. Circulation 2008

Epicardial VT Ablation: A Multicenter Safety Study Three tertiary centers; 2001 to 2008; 913 VT ablations; 156 (17%) epicardial

Patients Epicardial Mapping: Male: Age: Previous VT ablation: Ischemic: Dilated: ARVC: Idiopathic: Miscellaneous:

Epicardial VT Ablation: A Multicenter Safety Study Three tertiary centers; 2001 to 2008; 913 VT ablations; epicardial:156 (17%)

Methods and Results 134 109 56+15 yo 119 (76%) 51 39 13 17 14

Percutaneou Subxyphoid Approach Successful access: 134 Failled: 16 (11%)* *(8 previous surgery; 1Epicardial ICD)

Epicardial RF Application was necessary in 121/156 (78%) cases

Acute Adverse events N = 22 / 156 (14%) Epicardial bleeding:

08 (> 100cc)

RV perforation:

03

Coronary occlusion:

01 (transitory)

Long-term evolution Follow-up: 23± 21 months Delayed complications = • Important pericardites = • Cardiac tamponade = • Coronary occlusion =

4 2 1 (10 d) 1 (2 wks)

Sacher F et al. HRS 2009 Sacher F et al. HRS 2009

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Summary • The percutaneous and transvenous epicardial approaches can be performed safely in the EP lab and might improve the results of endocardial ablation in selected patients patients.. • Electrophysiological and electrocardiographic signals are useful methods to predict epicardial origin of a VT circuit and for scheduling an epicardial procedure.. procedure • Pericardial bleeding is the most frequent complication related to the percutaneous pericardial puncture, but it does not preclude performing the procedure in most patients patients.. • Irrigated tip catheters are the more effective alternative to ablate subepicardial fibers due to the epicardial fat; fat; however, it might increase coronary artery damage.. Cryoablation seems to be a safer alternative when ablating close to damage the coronary arteries arteries.. • The phrenic nerve position should be identified before RF delivering and some protection might be necessary to prevent its damage damage..

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