AF Symposium 2016
Bordeaux New ECGI Ablation Protocol—Re-Mapping During Ablation
by Steve S. Ryan, PhD
Why should patients be interested in a new mapping and ablation technique that isn’t yet available worldwide and in the US?
Why ECGI/ECVUE is Important
ECGI/ECVUE is probably the most significant, game changing improvement in treating A-Fib (along with Contact Force sensing catheters), particularly for people with persistent A-Fib.
ECGI will not only change the ways mapping and ablations are done, but possibly how you and I are examined and diagnosed in our doctor’s office.
Image a Future Physical Without an EKG
Imagine when you go in for a physical that, instead of getting an EKG, you simply put on an ECGI vest which tells the doctor where and how many A-Fib producing potentials you have in your heart, all without you having to be in A-Fib. Admittedly, this is pie-in-the-sky speculation right now. But the ECGI vest has tremendous potential to change the way A-Fib is diagnosed and treated.
Dr. Michel Haissaguerre & New Uses of ECGI/ECVUE
Dr. Michel Haissaguerre of Central Hospital, Bordeaux, France presented new developments in how the Bordeaux group now uses ECGI/ECVUE Cardio Insight body surface mapping for persistent A-Fib. His talk was entitled “Monitoring of AF Drivers During Catheter Ablation for Persistent AF.” (For a detailed description and discussion of the ECGI system, see 2013 BAFS: Non-Invasive Electrocardiographic Imaging [ECG]). See also How ECGI Works.)
Patient Prep with the ECGI Vest
Typically, the day before an ablation, a technician (it doesn’t have to be the EP ablationist) uses a ECGI vest to map and identify sites in the heart producing A-Fib signals (rotors and focal sources). The next day, using this map combined with a CT scan which produces a very detailed 3D color map of the heart, the EP ablates and isolates these sites.
What’s New: Bordeaux Group Also Re-Maps Using the ECGI Vest
What’s brand new about how the Bordeaux group is using ECGI is that, if a patient’s A-Fib has not been terminated after the ablation, they then re-map using the ECGI vest. This often reveals missed, changed or new A-Fib drivers. They then ablate/isolate these regions.
The ideal or goal is for A-Fib to terminate into sinus rhythm or Atrial Tachycardia (AT). Atrial Tachycardia (a heartbeat that is in sinus rhythm but faster than normal) can then also be mapped and ablated into Normal Sinus Rhythm (NSR). (Atrial Tachycardia, for the average persistent patient, feels a lot better than being in A-Fib.)
If after re-mapping and ablation, the patient is still in A-Fib, they use Electrocardioversion to try to shock the patient back into sinus.
See the AF Symposium Live Case Presentations: Dr. Mélèze Hocini of the Bordeaux group ablated a 40-year-old male with persistent A-Fib. She found four areas of rotor/focal activity in his heart. After ablating the third area, the patient’s persistent A-Fib terminated. Dr. Hocini did not have to re-map or ablate the fourth area.)
Slides of Before and After ECGI Ablation
Dr, Haissaguerre showed slides of before and after an ablation using ECGI. Ablation at a driver region transformed rapid, complex signals into slower, organized signals.
In the AFACART study in which eight different centers used the ECGI system, ablations in driver regions varied from 38 to 98 minutes of cumulative RF energy delivery time per center despite similar patients and targets (indicating the current lack of standardized ablation techniques). (For more on the AFACART study, see AF Symposium 2015: AFACART Clinical Trial.)
Persistent A-Fib Case: In the case of a 48-year-old female in Persistent A-Fib for four months, four target areas were identified: the inferior Left Atrium (LA), the LA Septum, the anterior of the LPV (Left Pulmonary Vein) to the LAA, and the posterior area of the RPV (Right Pulmonary Vein). (They divide the left and right atria into seven general physical areas.) A-Fib continued after these driver areas were ablated. On re-mapping, the septum area was found to be still active. After 2 more minutes of RF delivery to that septum area, A-Fib terminated into normal sinus rhythm.
Ablation Failure From Thicker Atrial Tissue?
Dr. Haissaguerre pointed out that ablation failure happens particularly in the right and left atrial appendages because of thicker atrial tissue. He showed a slide where he ablated one driver area, then six months later ECGI showed a new driver region at the LAA ridge.
Right Atrium Drivers Reduced After Left Atrium Ablation
Next, he showed slides where the ECGI mapping system initially showed driver activity in the Right Atrium (RA). But after Left Atrium (LA) ablation, this driver activity was greatly reduced. He suggested that RA drivers might mirror or be a projection of LA drivers.
(This is a new research finding that may be very important and may change the way the right atrium is ablated in persistent A-Fib cases.)
ECGI After Prior Extensive PVIs
Dr. Haissaguerre showed slides of patients who had had two or three prior PVIs. ECGI clearly showed where there were still driver regions. Each patient’s persistent A-Fib was terminated into normal sinus rhythm.
Mapping of Atrial Tachycardias (ATs)
The ECGI system can also map Atrial Tachycardias (AT). Dr. Haissaguerre found that half the ATs found were focal ATs, “mostly localized reentry”; 68% were from driver regions previously ablated; 32% were from new sites.
The other half of the ATs were “Macroreentries” and required linear ablations to terminate.
Limitations of ECGI NonInvasive Driver Mapping
According to Dr. Haissaguerre:
• Body filtering (ECGI) may miss small local AF Signals, while showing the main propagating waves in a panoramic scope
• Extensive ablation may affect egm (electrogram) quality and analysis
• Besides ‘drivers’, other mechanisms of AF perpetuation may coexist, particularly in longer lasting (>1 year) AF
Dr. Haissaguerre’s Conclusions
• Remapping can confirm elimination or persistence of drivers or show new drivers (requiring further ablation)
• This dynamic information will probably increase the rate of AF termination
• Further improvement expected with rapid mapping of Atrial Tachycardias
What Patients Need to Know
The ECGI/ECVUE Cardio Insight body surface mapping seems like a major improvement and development, particularly for patients in persistent A-Fib, usually the hardest to cure.
This ECGI system is being carefully developed in eight centers in Europe (AFACART clinical trial). It was recently purchased by Medtronic and is headquarted in Dublin, Ireland.
(No one at the Medtronic booth at the AF Symposium exhibit hall could tell me when the ECGI system will be available for examination and use in the US and worldwide. I’ll update this report when I know.)
Re-Mapping a Major Improvement in ECGI: We’re grateful to Dr. Haissaguerre and the Bordeaux group for developing the technique of re-mapping during an ablation. It’s certainly a major improvement in what was already a very good mapping and ablation system.
Mapping and Ablating Atrial Tachycardias (ATs): From a patient’s perspective, it’s great to know that ECGI can be used to identify and ablate atrial tachycardias (fast heart rates).
A-Fib termination can result in normal sinus or ATs which are a form of sinus rhythm. For most people, ATs are certainly better than being in A-Fib. But they can be annoying and disruptive. It’s good to know they can be mapped and ablated just like A-Fib signals.
ECGI May Miss Small Local ATs and A-Fib Signals: ECGI isn’t perfected yet. Dr. Haissaguerre showed that many of the local ATs found came from driver regions previously ablated.
DR. MICHEL HAÏSSAGUERRE
Dr. (Prof.) Michel Haïssaguerre, Central Hospital, Bordeaux, France, and his colleagues invented pulmonary vein catheter ablation for A-Fib (PVA/I). The Bordeaux Group is considered one of the top A-Fib centers in the world and noted for their cutting edge research in the treatment of Atrial Fibrillation. Interesting fact: I (Steve Ryan) was their first US patient in 1998.
If you find any errors on this page, email us. Y Last updated: Thursday, February 11, 2016