2007 venezia, congresso mondiale, ablazione delle tachicardie ventricolari

1. Stefano Nardi MD, PhD
““SANTA MARIA” GENERAL HOSPITAL - TERNISANTA MARIA” GENERAL HOSPITAL - TERNI
THORACIC SURGERY ANDTHORACIC SURGERY AND
CARDIOVASCULAR DEPARTEMENT ARRHYTHMIA ELECTROPHYSIOLOGCARDIOVASCULAR DEPARTEMENT ARRHYTHMIA ELECTROPHYSIOLOG
CENTER AND CARDIAC PACING UNITCENTER AND CARDIAC PACING UNIT
Venice Arrhythmias ‘07Venice Arrhythmias ‘07
Mapping and Ablation ofMapping and Ablation of
late post-ischemiclate post-ischemic
sustained Ventricularsustained Ventricular
Tachycardias, guided byTachycardias, guided by
EnSite System.EnSite System.

2. Post-ischemic sustained VTsPost-ischemic sustained VTs
How does it work?

3. Methodology
• Identification of protected isthmuses of
conducting tissue related to slow conduction zone
• electrically (entrainment with concealed fusion)
• anatomically (computer-assisted,3D-mapping)
RF lesion bridges between constraining barriers
Interventional Therapy
Post-ischemic sustained VTsPost-ischemic sustained VTs

4. How can we approach ?How can we approach ?
MappingMapping
• Point by pointPoint by point
• EPEP
criteriacriteria
TrackingTracking
• XrayXray
• CARTOCARTO
• LocaLisaLocaLisa
• NavXNavX
• RPMRPM
• ICEICE
AblationAblation
• ConventionalConventional
• 8 mm tip8 mm tip
• Irrigated tipIrrigated tip
• InvestigationalInvestigational
(balloon, cryo...)(balloon, cryo...)- Framework for ablationFramework for ablation
- Mapping guidanceMapping guidance
- Anatomic localizationAnatomic localization
- Tagging of ablation sites- Tagging of ablation sites
- DetermineDetermine
catheter contactcatheter contact
- ImprovedImproved
efficiency ofefficiency of
power deliverypower delivery
Post-ischemic sustained VTsPost-ischemic sustained VTs

5. EP drawbacks
• High complex SUBSTRATE
• Non-uniform distribution of MYOCARDIAL SCAR
• Imprecise fluoro guidance in ISCHEMIC BORDER ZONE
• Imprecise creation of contiguous lesions
Post-ischemic sustained VTsPost-ischemic sustained VTs

6. Clinical Carachteristic
 Nr pts : 24 (48%)
 Age: 63,79 ± 7,84 yrs
 Sex (M/F): 16/8
 LVEF: 30,41 % ± 4,48
 Nº ep/mo: 1,92 ± 0,79
 NYHA II-III class
Post Ischemic sustained VTsPost Ischemic sustained VTs
 76 pts with ICD implant
 SVTs despite 2/3 AADs
 50/76 pts eligible
From 04/04 to 10/06

7. - CREATE a virtual geometry of LV chamber
- IDENTIFY the target zone of each SVT
(low-voltage zone, diastolic potentials, scar)
- DESCRIBING the EA and EP characteristics of the
substrate
- EVALUATE the efficacy of RF lesions at the
identified critical isthmus
- DEMONSTRATE with post-RF EP study the non-
inducibility of SVTs.
operative end pointsoperative end points
Post-ischemic sustained VTsPost-ischemic sustained VTs

8. Post Ischemic sustained VTsPost Ischemic sustained VTs
Results

9. Post-ischemic sustained VTsPost-ischemic sustained VTs
Results

10. RFCA consisted in a series of contiguous CTR RF guided by EA
activation map and EP criteria of atrial potentials
Post Ischemic sustained VTsPost Ischemic sustained VTs

12. • Procedure (min): 148±26 144±24 151± 29
Global SR VT
• Fluoroscopy (min): 59±17 58±16 66±19
• Mapping (min): 35±8 33±9 38±4
• Pulses of RF: 34±16 28±17 41±19
Post Ischemic sustained VTsPost Ischemic sustained VTs
Results

13. Procedure (min): 148±26
Fluoroscopy (min): 59±17
Mapping (min):
35±8 Nr. Pulses
of RF: 37±16
24/27 SVTs operative mechanism (88%)
Acute EfficacyAcute Efficacy
24/27 SVTs (85%)24/27 SVTs (85%)
InefficacyInefficacy
4/27 SVTs (15%)4/27 SVTs (15%)
Post Ischemic sustained VTsPost Ischemic sustained VTs
Results
After mean FU of 13,4±6,7 18/20 pts free SVTs

14. Post Ischemic sustained VTsPost Ischemic sustained VTs
Ablation

15. Post Ischemic sustained VTsPost Ischemic sustained VTs
Ablation

16. Post Surgical AT MechanismsPost Surgical AT Mechanisms
• Complex anatomical model
• Multiplicity of simultaneously ongoing
wavefronts
• Short CL (<225ms)
• Variation of AT
• Haemodynamic instability
InefficacyInefficacy
4/27 SVTs4/27 SVTs
(15%)(15%)

17. POTENTIAL SUBSTRATES
How does it work?
Post-ischemic sustained VTsPost-ischemic sustained VTs

18. Conclusions (1)Conclusions (1)
• Conventional EP mapping
it’s not always appropriate
strategies for SVTs
ablation because it
provides very limited
understanding of these
complex arrhythmias which
are highly variable from
one pt to the other.
• The main drawback of a pure
EP approach is that the
identification of all putative
“endpoint” could be extremely
difficult to achieve.

19. Post-ischemic sustained VTsPost-ischemic sustained VTs
• The implemented use of
virtual geometry and a
combined approach of EP
with EA criteria is able
to allow us a realistic
3D reconstruction of LV
• An individually tailored
approach is needed
• A combined approach may
be useful in the treatment
of pts where RFCA is
primarily both EP and EA
based.

20. What is success?
• Complete freedom of VF, off drug RX?
• No symptoms, but drug Rx required?
• Dramatic decrease in symptoms, but AADs
still required?
• QoL
• How do we detect asymptomatic episodes?
• Anticoagulation ………………...?
QUESTIONSQUESTIONS

21. Post Ischemic sustained VTsPost Ischemic sustained VTs

22. Post Ischemic sustained VTsPost Ischemic sustained VTs

23. - Related to the slow conduction
regions located in the MI region
or at the border zone
Post-ischemic sustained VTsPost-ischemic sustained VTs
- Macro-reentry is the most
frequent mechanism
- Larger is the area of tissue
infarted larger is the
probability of potential
reentrant circuits
How does it work?