Identification and Identification and

Ablation of Epicardial VTAblation of Epicardial VT

Yi-Gang Li, MDYi-Gang Li, MDXinhua Hospital, Shanghai Jiaotong Xinhua Hospital, Shanghai Jiaotong

UniversityUniversity

• Present clinical data• Previous history• Surface ECG during VT• Mapping data• Cardiac Image

When to go epicardiallyWhen to go epicardially

Identification of Epicardial VTIdentification of Epicardial VT

• Present clinical data

- Echocardiography: -- LV thrombus if their anticoagulation can be safely interrupted for the procedure

1 Daniels DV, et al. Circulation 2006

When to go epicardially ?When to go epicardially ?

• Presence of SHD

Frequency of Epicardial OriginFrequency of Epicardial Origin

- Chagas’s disease - 36% of a series of 138 VT pts1

- Non-ischemic SHD - 25%-45%1,2,3

- Ischemic SHD - 1/3 P subepicardial reentry circuits4 -- Posterolateral MI 4,5 -- Aneurism related VT

1 Sosa E, et al. JCE 2005. 2 Hsia HH, et al. Circulation 2003, 3 Soejima, et al. JACC, 2004. 4 Svenson, et al. JACC 1990. 5 Berruezo et al. Circulation 2004.

• Presence of SHD

Frequency of Epicardial OriginFrequency of Epicardial Origin

- AVRT – 5-10%?- Other (“Idiopathic” LV aneurysm, sarcoid, noncompaction)

- Idiopathic LVOTVT(12%-30%) - LV epicardium (1/3) – perivascular1

1 Daniels DV, et al. Circulation 2006

• Absence of SHD

• Previous history

When to go epicardiallyWhen to go epicardially

Previous failed VT ablation attempt 1

- Select truly epicardial VTs Suc. rate150 VT ablation Pts

Incessant VT: 19 Pts(12.7%)

Endo abl. 10 Pts (53%) Epi abl. 8 Pts (42%)

Suc. Rate: 95%

1 Brugada et al, JACC 2003;41:2036–2043ESC 2008

Mapping data in presence of SHD

• Mapping data inability to identify the reentry circuit isthmus on the endocardium by entrainment mapping• Identification of a focal point of earliest endocardial activation, entrainment indicates an exit or outer loop site, but abl. fails to interrupt VT

Identification of Epicardial VTIdentification of Epicardial VT

Mapping data in absence of SHD (LVOT?)

• Mapping data within CS and accessible LV branches suggest an epicardial VT circuit or focus

Identification of Epicardial VTIdentification of Epicardial VT

ECG Recognition of the Epicardial Origin of VTECG Recognition of the Epicardial Origin of VT• Analysis of ECG pattern inAnalysis of ECG pattern in

– (A): 14 successful epicardial VT ablation after failed endocardial (A): 14 successful epicardial VT ablation after failed endocardial approach,approach,

– (B): 27 successful endocardial VT ablation,(B): 27 successful endocardial VT ablation,– (C): 28 additional VTs that could not be ablated from the endocardium(C): 28 additional VTs that could not be ablated from the endocardium

• Four distinct intervals of ventricular activation were measured:Four distinct intervals of ventricular activation were measured:

(1)(1) the pseudo-delta wavethe pseudo-delta wave: from the earliest ventricular activation to the : from the earliest ventricular activation to the earliest fast deflection in any precordial leadearliest fast deflection in any precordial lead

(2)(2) the intrinsicoid deflection timethe intrinsicoid deflection time: interval measured from the earliest : interval measured from the earliest ventricular activation to the peak of the R wave in V2.ventricular activation to the peak of the R wave in V2.

(3)(3) the shortest RS complexthe shortest RS complex: interval measured from the earliest ventricular : interval measured from the earliest ventricular activation to the nadir of the first S wave in any precordial lead.activation to the nadir of the first S wave in any precordial lead.

(4)(4) the QRS complexthe QRS complex: earliest ventricular activation to the offset of QRS in the : earliest ventricular activation to the offset of QRS in the precordial leads.precordial leads.

Berruezo A. Circ 2004;109:1842Berruezo A. Circ 2004;109:1842

Groups A & C (unsuccessful endocardial ablation) showed

longer intrinsicoid deflection in V2,

slurred initial part of QRS(pseudo wave)

vs

Group B (endocardially ablated VT)

Berruezo A. Circ 2004;109:1842Berruezo A. Circ 2004;109:1842

Identification of Epicardial Origin of VTIdentification of Epicardial Origin of VT

SensitivitySensitivity Specificity

Pseudo-delta wave Pseudo-delta wave ≥≥ 34 ms 34 ms 83% 83% 95%95%

intrinsicoid deflection intrinsicoid deflection ≥≥ 85 ms 85 ms 87%87% 90%90%

RS complex duration RS complex duration ≥≥ 121 ms 121 ms 76%76% 85%85%

ECG Characteristics of VTsECG Characteristics of VTs

(msec)(msec)Group AGroup A(n=14)(n=14)

Group BGroup B(n=27)(n=27)

Group CGroup C(n=28)(n=28)

Pseudo-delta wavePseudo-delta wave 4343±±99 1616±±99 4242±±99

Intrinsicoid deflectionIntrinsicoid deflection 9797±±2121 6565±±1515 9898±±1414

Shortest RS interval 149±39 91±20 132±30

QRS complex 217±24 174±37 195±27

Group C vs B, group A vs B, P<0.05. Group C vs B, group A vs B, P<0.05. Group A vs C, P=NSGroup A vs C, P=NS

VTs from epicardial origin (groups A & C) showed a significantly longer pseudo-delta VTs from epicardial origin (groups A & C) showed a significantly longer pseudo-delta wave, intrinsicoid deflection, and RS complex duration compared to VT with wave, intrinsicoid deflection, and RS complex duration compared to VT with endocardial origin (group B).endocardial origin (group B).

PDI=A/QRS

Hachiya H, et al. Circulation 2010;74:256-261Hachiya H, et al. Circulation 2010;74:256-261

ECG Recognition of the Epicardial Origin of VTECG Recognition of the Epicardial Origin of VT

Hachiya H, et al. Circulation 2010;74:256-261Hachiya H, et al. Circulation 2010;74:256-261

ECG Recognition of the Epicardial Origin of VTECG Recognition of the Epicardial Origin of VT

Hachiya H, et al. Circulation 2010;74:256-261Hachiya H, et al. Circulation 2010;74:256-261

Hachiya H, et al. Circulation 2010;74:256-261Hachiya H, et al. Circulation 2010;74:256-261

ECG Recognition of the Epicardial Origin of VTECG Recognition of the Epicardial Origin of VT

Valles E, et al. Circulation 2010;3:63-71

V2

MDI=IDT(Shortest)/QRSd

Valles E, et al. Circulation 2010;3:63-71

Epi vs End. Pace maps

Valles E, et al. Circulation 2010;3:63-71

Valles E, et al. Circulation 2010;3:63-71

Epi vs End. VT Morphology

11 Pts, 21 VTs

from basal superior or lateral origin

Valles E, et al. Circulation 2010;3:63-71

ECG Recognition of the Epicardial Origin of VTECG Recognition of the Epicardial Origin of VT

Ablation of Epicardial VTAblation of Epicardial VT

Sosa E, Scanavacca M. JCE 2005;16:449–452

Ablation of Epicardial VTAblation of Epicardial VT

• Mapping of the epicardium can be performed

using fluoroscopy and/or CARTO system.

• Areas of infarction or scar have low amplitude

electrograms similar to findings during

endocardial mapping.

• Epicardial fat may create low amplitude

regions.

- Inability to capture during epicardial

pacing

- High pacing tresholds: Epicardial fat;

difficult catheter stability

Mapping of Epicardial VTMapping of Epicardial VT

• Mapping using conventional or Navi-Star Catheter

(Biosense-Webster)

• Internally or externally irrigated catheter can be

used for RF ablation to avoid high impedance

• Power limit of 50 W with temperature limit of 45ºC,

infusion rate of 17 ml/min and duration of 110 sec

• Aspiration of pericardial fluid after 5 RF

applications to prevent fluid accumulation

Mapping and Ablation of Mapping and Ablation of Epicardial VTEpicardial VT

Ablation of Epicardial VTAblation of Epicardial VT

Pts

[n]

Acute suc.rate

[%]

Late suc. Rate

[%]

complication

[%]

Sosa 1 14 39 100 0

Schweikert ² 30 71 97 0

Brugada ³ 10 80 90 0

Soejima 4 28 73 54 0

1 J Am Coll Cardiol 2000;35:1442–9; 2 Circulation 2003;108:1329-1335; 3 J Am Coll Cardiol 2003;41:2036–43, 4 J Am Coll Cardiol 2004;43:1834–42

QRS=180 msCL=585 ms

Ablation of Epicardial VTAblation of Epicardial VT

Phrenic nerve injury

• Pacing shoud be performed before energy

delivery to indenify phrenic nerve capture,

indicating where ablation might cause

diaphragmatic paralysis.

• phrenic nerve injury can be avoided by:

- interposing a sheath,baloon, or even air in the

pericardium between the abl. Site and the

nerve.

ComplicationsComplications

• Coronary nerve injury

- Coronary angiography before RF ablation

- Requiring a minimum of 4 mm between

epicardial coronary vessels and the ablation

catheter.

- the catheter is not touching the vessel at any

point of cardiac cycle

• Pericartitis

- mild, limited duration, often responds well to

anti-inflammatory medication

ComplicationsComplications

• Epicardial mapping will not prevent all VT abl.

failures.

- Tachycardia circuits can originate from deep

within the ventricular septum/myocardium, may

require transcoronary ethanol ablation, or

irrigated needle catheters.

• Ablaion can be limmited by

- epicardial fat,

- proximity to coronary arteries and other other

stuctures

Problems in eProblems in epicardial ablation ablation

Conclusion

• Epicardial VT can be identify by previous history, present clinical data and surface ECG

• Mapping data and cardiac Image facilitate VT ablation

• Epicardial VT is rare, but it can be either focal

or macroreentry

• Epicardial catheter techniques expand the

options for investigating and treating VT