1. Catheter Ablation of
Ventricular Tachycardia
Lin Yenn-Jiang MD. Chen Shih-Ann MD.
April 15, 2012
Advanced EP training,
St. Jude Medical, Taipei
Taiwan Heart Rhythm Society
Division of Cardiology, Taipei Veterans General Hospital
and National Yang-Ming University, Taipei, Taiwan

2. Experience of VT EPS/ABL
in Taipei VGH 2001-2011
61%
DCM
12%
CAD
9%
ARVC
9%
OT
FVT VT 4%
2%
1%
1%

3. Survival of VT Patients According to National
Mortality Data Base of Taiwan (up to 2011)
P=0.007
Fascicular VT
RV-VT
ARVC
Brugada,VF
CAD, DCM

4. Different types of VT
Focal Type Reentrant Type
Mapping and ablation VT differ by underlying
Pace condition and tachycardia mechanism.
mapping, Activation map, Entrainment technique, substrate
Unipolar electrogram morphology mapping, Electrogram
characteristics

5. Focal Ventricular Tachycardia

6. Reentrant Ventricular
Tachycardia
RVOT
Septum
LV apex
ICD Lead
Lin YJ et al. HRS abstract 2010

7. How to Map VT
 Tools
 Surface ECG: origin, exit
 Pace mapping
 Entrainment technique: during VT,
 3D activation and substrate mapping:
 Stable VT: NavX, Carto
 Unstable VT: Ensite Array, substrate map
during sinus rhythm
 Location: RV, LV, and Epicardium
 ECG, substrate map, activation map

8. Outlines
 Outflow tract VT.
 ARVC/D.
 LV Fascicular VT.
 Papillary muscle VT.
 CPVT, BBRVT.
 Substrate VT: CAD, DCM.

9. Outflow Tract Ventricular
Tachycardia (OT-VT)
 VT arises from the right ventricular outflow
tract (RVOT-VT, left ventricular outflow
tract (LVOT-VT), aortic cusps (Cusp VT),
and from the pulmonary artery (PA VT)
 OT-VT tend to occur in the absence of
structural heart disease and are focal in
origin, the 12-lead ECG recorded during
VT is a precise localizing tool.

10. Clinical Features of RVOT-VT
 RVOT VT constitutes 75% of all patients
with outflow tract VT
 RVOT VT is more common in females
30-50 years old.
 Symptoms include palpitations, dizziness,
atypical chest pain, and syncope.
 Exercise testing reproduces the patient’s
clinical VT 25 to 50% of the time.

11. Mechanism of RVOT-VT
 Most forms of RVOT VT are sensitive to
adenosine
 Most likely mechanism is catecholamine
mediated DAD and triggered activity.
 Mediated by the activation of cyclic AMP.
 Can be induced in the EP lab with
isoproterenol, aminophylline, atropine, and
rapid burst pacing but rarely with
programmed ventricular extrastimuli.

12. RVOT VT
I
II
III
aVR
aVL
aVF
V1
V2
V3
V4
V5
V6

13. Outflow Tract Anatomy
1. Important overlapping
nature of the outflow
tract course!
2. RVOT and PA lie
anterior and to the left
of the LVOT and aorta.

14. RVOT VT: Pace mapping ECG morphology

15. Pulmonary Artery VT

16. Cross over of RVOT & LVOT region
Left I: biphasic,
V1 :W
L
R I: positive
L
V1 :RS
R Ant
Right
AP view Superior view
David Callans JCE 2009

17. How to D/D RVOT and VT with
ASC in origin

18. LVOT and Aortic Cuspid VT
 VT arising from the LVOT shares similar
characteristics to the RVOT VT because of a
common embryonic origin.
 ECG: LBBB with inferior axis with small R-
waves in V1 and early precordial transition
(R/S 1 by V2 or V3) or RBBB morphology with
inferior axis and S-wave in V6.
 Aortic cusp VT accounts for up to 21% of
idiopathic VT.
 More commonly arises from the LCC, than the
RCC and rarely arise from the NCC.

19. Aortic Cusp VT Morphology

20. Tabatabaei and Asirvatham. Circ EP 2009;2:316-326

21. LVOT VT Morphology

22. Mapping Tool for OT-VT
 ECG morphology
Could be non-inducible
 Pace mapping
Could be large area 2 cm2: different chamber, scar, or
epicardium,
 Activation map
More accurate: remain unsuccess: more mapping sites,
epicardium, different energy sources,

23. Spontaneous PVC Pace
Mapping
Taipei VGH 2010

24. PVC Disappearance Just After RF

25. Difficulty in Pace Mapping in RVOT-T (1)
A VT PM 1 PM 2 B
RVOT
2 1
Septal wall
Anterior wall
Free wall
Taipei VGH 2010

26. Difficulty in Pace Mapping in RVOT-T (2)
Schema of the Ventricular Arrhythmia Origin, Breakout Site, and
Preferential Conduction From the LCC to the RVOT
T. Yamada, et al
JACC, 2007,
Vol.
50, No. 9: 884-91

27. RVOT-T : 3D mapping
Voltage of SR Spectral Analysis Activation of VT
3.5 cm
from PV
Successful site
septum
Free
wall
0.018
0.016
Eg during SR 0.014
0.012
Scar in the free wall site 0.010
0.008
0.006
0.004
0.002
0.000
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300

28. Summery
 Carefully ECG interpretation and EP study to
localize the optimum ablation site for VT.
 Usually not life threatening, and could be treated
conservatively.
 3D mapping system can be helpful (activation
map or substrate map), but correct chamber, far-
field sensing, preferential conduction need to be
considered.

29. Outlines
 Outflow tract VT.
 ARVC/D.
 LV Fascicular VT.
 Papillary muscle VT.
 CPVT, BBRVT.
 Substrate VT: CAD, DCM..

30. Idiopathic RVOT-T
 Right ventricular outflow tract tachycardia
(RVOT-T) represents up to 10% of all ventricular
tachycardias (VTs), and is considered as a
benign disease.
 Symptoms: Ranging from none to palpitations,
lightheadedness, dyspnea, or syncope.
 Arrhythmias: Frequent isolated PVCs, bursts of
nonsustained VT, or sustained tachycardia often
facilitated by catecholamines or exercise.
 Ablation: Acute success rate of focal ablation of
RVOT-T is 65–97% with rare complications.

31. Arrhythmogenic RV Dysplasia
 Cardiomyopathy begins in RV with poor contractile
function and dilatation, progresses to LV finally.
 Histology: RV muscle becomes replaced by adipose
and fibrous tissue.
 Arrhythmia: Re-entrant Type (scarring & late
Potentials) with LBBB type ECG;
 ECG: Diffuse T wave inversion over precordial leads,
and Epsilon Wave.
 Ablation: The effect of catheter ablation is
temporizing, 1/3 epicardium, mostly reentry.
Implanted cardioverter defibrillator (ICD) is the only
reliable therapy for sudden cardiac death.

32. Task Force Criteria
TF (Definite +) if meet 2 major or 1 major 2 minor criteria
McKenna et al. 1994, BMJ

33. TF Criteria
 Positive TF criteria is important to diagnose
ARVC/D and is specific to detect the future
VF/ICD implantation/ CV mortality
 Malignant ventricular arrhythmia and late
recurrences may occur in patients with mild
or atypical form of arrhythmogenic RV
cardiomyopathy.

34. ECG of End stage ARVC
RVEF=10%, LVEF=15%

35. RV-VT, ARVC/D

36. Multiple VT morphology in ARVC/D
Sinus rhythm
voltage map

37. Peri-valvular VT in a Patient with ARVC/D
Europace 2005

38. Electrophysiology
Not Fulfilling TF
Definite ARVC
RVOT-T (RVOT-VT)
21.6%
P value
78.4%
Catheter mapping
RV ERP (msec) 215 ± 22 238 ± 32 0.016
Inducible sustained VT 24% 59% 0.001
Requirement of
53% 26% 0.016
isoproterenol infusion
Tachycardia cycle
315 ± 67 277 ± 94 0.109
length (msec)
3D mapping
Scar in the RVOT
37% 57% 0.416
(voltage <0.5 mV)
Scar in the RV body 47% 57% 0.697
Total RV conduction
129 ± 46 222 ± 77 <0.001
time (msec)
Chen SA et al. 2011 HRS abstract

39. Predictor of VT Recurrence
After Ablation in TF (-) Patients
VT VT Multivariat
Odds ratio
Factors recurrence recurrence e analysis
CI (95%)
(+) (-) P value
TF criteria (1 major
7.5
one minor, or 3 35% 13% 0.055
0.95-59
minors)
Substrate Mapping
5.9
RV body & free wall 46% 17% 0.047
1.02-34
scar
Distance to the
1.1
pulmonary valve 29±19 19±10 0.047
1.01-1.17
(cm)
The presence of Scar / Foci in FREE WALL
indicated future recurrence in TF (-) patients
Chen SA et al. 2010 HRS abstract

40. Long-Term Outcome
(Mean follow-up time for more than 2 years)
Cumulative Incidence Cumulative Incidence
TF (-), 3.1% TF (-) : 14%
TF (+) , 7.4% TF (+): 36%:
P=0.511 P=0.019
Follow-Up Duration
Follow-Up Duration
All Cause Malignant
Mortality arrhythmias

41. Kaplan-Meier analysis of survival free of rapid
VT/VF event in ARVC patients

42. Summery of ARVC/D
 The most specific criteria to predict the outcome of
ARVC patients: TF criteria.
 Detection of atypical and early form of ARVC from
idiopathic RVOT-T: Substrate mapping.
 Substrate characteristics of ARVC: Diffuse LVZ and
longer activation time, and abnormal substrate in the
Epi-endocardium; Tachycardia: both focal and
reentrant.

43. Outlines
 Outflow tract VT.
 ARVC/D.
 LV Fascicular VT.
 Papillary muscle VT.
 CPVT.
 Substrate VT: CAD, DCM, Brugada S.

44. LV fascicular VT
 Most common left ventricular VT
 Morphology: RBBB pattern (post. fascicular type:
superior axis and LAD. incidence 90%; ant. fascicular
type: inferior axis, and RAD; incidence 10%)
 is a reentrant VT that originates from the Purkinje
network near the left ant or posterior fascicle without
structural heart disease.
 This VT can be ablated by the diastolic potentials (P1
or DP) or Purkinje potentials during VT.

45. Posterior Fascicular VT

46. Diastolic potential & Purkinje potential

48. A B
LPF
A
H P1
P2
(LPF)
P2 LVS
exit
P1 P1: antegrade limb
LVS: retrograde limb
100 ms P2 (LPF): bystander

49. Posterior Fascicular VT

50. Where to Target
 P1 (DP) in the mid-septum of
LV (28-130 ms before QRS).
The earliest P1 is not required,
usually targeting the lower 1/3
of the P1 to avoid AVB.
 If P1 could not be identified,
target the fused and earliest P2
(PP) near the exit site of the
tachycardia.
 Perfect QRS match during
pace mapping may not be
required.
 Anatomic-guided linear
ablation, longitudinal transect
the limb of FVT.
 Conventional catheter is enough

51. Outlines
 Outflow tract VT.
 ARVC/D.
 LV Fascicular VT.
 Papillary muscle VT.
 CPVT, BBRVT.
 Substrate VT: CAD, DCM.

52. LV Papillary M VT (PM-VT)
 Catecholamine sensitive VT, arising from anterior
and posterior papillary muscle.
 Relative benign course in the follow-up
 Focal and non-reentrant in mechanism. Mostly
presented with burst VPCs, Extra-stimulation
induced VT (-), entrainment (-).
 Require advanced imaging to locate the PM-VT
(angiography, TEE, ICE…)
 Could required multiple site ablation and irrigated RF
to achieve long-term success.

53. Location of
Ant. and post. PAP M
JCE, Vol. 20, pp. 866-872, August 2009

54. Surface ECG
Negative
Wide QRS
Early transition

55. VPC SR
Intracardiac recording

56. ECG of Post. PAP VT
Circ Arrhythmia Electrophysiol. 2008;1:23-29

57. Differentiation of PM-VT and
Fascicular VT
Heart Rhythm, Vol 5, No 11, November 2008

58. Outlines
 Outflow tract VT.
 ARVC/D.
 LV Fascicular VT.
 Papillary muscle VT.
 CPVT, BBRVT.
 Substrate VT: CAD, DCM.

59. Baseline EP characteristics: BBRVT
• BBRVT: Old patients ,
structure heart disease
• RBBB or LBBB,
• Reentry: PPI<30 at
RVapex, Critical delay of
His-Purkinje system
• HV longer than SR,
• HV during SR not normal

60. CPVT

61. 3. Activation Mapping, during tachycardia
Bidirectional VT, CPVT

62. ECG after ablation

63. Outlines
 Outflow tract VT.
 ARVC/D.
 LV Fascicular VT.
 Papillary muscle VT.
 CPVT, BBRVT.
 Substrate VT: CAD, DCM.

64. Substrate VT
 Localization of chamber (RV, LV, or Epi)
 Localization of the disease susbtrate..
 Identify the circuits of VT/VF, potential
exit/entrance sites for VT/VF, by
activation/entrainment during VT/VF and
substrate during SR.
 Determination of the targets for ablation.

65. Strategy for Substrate
VT/VF ablation
 Mappable/ inducible VT: Identification of the
circuits and use of entrainment technique.
 Unstable VT: substrate mapping during SR, use
device, AAD to slow the VT rate.
 Non-inducible VT: substrate mapping, pace
mapping, consider autonomically or
ischemically/mediated VT
 Ineffective ablation: energy source, extensive
ablation, or epi/intramural in origin.

66. 1. Localization of VT by ECG
 Bundle branch morphology: RBB: LV, LBB: RV or
LV septum.
 Superior and inferior axis: sup. and inferior LV
 Precordial transition: dominant R: mitral to basal,
dominant S: anterior apex in location.
 Positive concordance: Mitral annulus, negative
concordance: LV apex.
 Slurred wave, wider QRS, Q wave of lateral leads
for LV-VT, R wave in RV-VT: Epicardial in position.

67. 2. Entrainment technique

68. 3. Electrogram Characteristics
Abnormal Normal
Bipolar Eg: < 3 deflection, > 2 mV, <
70 msec, amplitude/duration<0.05

69. 4. Substrate Mapping: Strategy
Zipes DP et al. Catheter Ablation of
Arrhythmias, 2nd edition, 2002

70. Case 1 Ventricular Tachycardia RV ICD Lead Pacing

71. Bi-Ventricular Voltage Map
LVZ
LVZ
LVZ
Ablation site
Lin YJ et al. HRS abstract 2009

72. Ischemic LV VT---Case 1
The important to identify chamber to ablate
RVOT
Septum
LV apex
ICD Lead
Lin YJ et al. HRS abstract 2009

73. Lin YJ et al. HRS abstract 2009

74. Ischemic LV VT---Case 2
The important to identify the LVZ and critical
Channels and exit site
Tsai and Chen, Circ J, 2011

75. Conclusions
 Outflow tract VT is the commonest form of
idiopathic VT.
 ECG morphology is important for localization
of focal VT and exit site of substrate VT.
 Pacing mapping may not sensitive to locate
the sites of foci in certain patients with focal
VT, scar-VT, epicardial VT, and fascicular VT.
 In the stable VT of abnormal ventricular
substrate: activation maps and entrainment
technique are important to decide the targets.
 In unstable VT, VF, and non-inducible VT,
substrate mapping during SR could be identify
to determine the critical substrate.

76. Brugada syndrome---Case 3
Identification of LVZ and prolonged potentials
Bipolar Eg > Unipolar Eg
1.5mV > 5mV
Abnormal
RV RV
endocardium endocardium

77. Brugada syndrome---Case 3
Late potential maps
RV
endocardium RV epiardium

78. Post ablation> No inducible VT/VF

79. Changes in ECG during the procedure
Before epicardial puncture After epicardial puncture