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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Application of Decrement-Evoked Potential (DEEP) mapping during Atrial Fibrillation Ablation
Scientific title
An observational study of Decrement-Evoked Potential (DEEP) mapping during standard Atrial Fibrillation Ablation to establish feasibility and predictive power for Atrial Fibrillation Recurrence
Secondary ID [1] 296447 0
Universal Trial Number (UTN)
Trial acronym
Atrial DEEP
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Atrial Fibrillation 310223 0
Condition category
Condition code
Cardiovascular 308956 308956 0 0
Other cardiovascular diseases

Study type
Patient registry
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
The study procedure involves the addition of pacing manoeuvres to map additional potentials called Decrement Evoked Potentials (DEEP), during standard procedures for ablation of persistent AF in patients who are clinically referred for an AF ablation procedure. The feasibility of delivering this pacing and measuring responses in atrial tissue will be tested, the relationship of DEEP areas to areas of scar and other signal abnormalities on voltage and activation mapping established (DEEP has recently shown promise in guiding ventricular tachycardia ablation) and the ability of DEEP to predict which patients will have AF recurrence explored. Pacing will be delivered at the end of the procedure by the electrophysiologist, after pulmonary vein isolation ablation, and will be with a drive train (S1=500ms) and extra stimulus (S2) at atrial Effective Refractory Period + 20ms, from specific protocol-specified sites in the left atrium. These include the left atrial appendage, roof, inferior-posterior wall, superior-posterior wall, anterior wall, mitral isthmus, high septum, low septum and inferior left atrium. Pacing for DEEP mapping will occur during the standard post-ablation waiting time, and will be additional to the usual ablation procedure, but will result in minimal additional procedural time compared to standard AF ablation. All analysis of DEEP will be performed offline post-procedure. Follow-up duration will be 12 months.
Intervention code [1] 312772 0
Diagnosis / Prognosis
Comparator / control treatment
No control group
Control group

Primary outcome [1] 307921 0
Feasibility of DEEP mapping in the atrium during atrial fibrillation ablation procedure - ability to perform effectively with adequate signal quality to interpret results with reference to known DEEP parameters. Signal quality and reproducibility of electrograms will be assessed for consistency and signal-to-noise ratio and consensus from investigators obtained as to whether quality is adequate for interpretation and future application.
Timepoint [1] 307921 0
At initial AF ablation procedure.
Primary outcome [2] 307922 0
Clinical Recurrence of Atrial Fibrillation as detected on follow-up holter monitor or 12-lead ECG.
Timepoint [2] 307922 0
End of study follow-up (12 months).
Secondary outcome [1] 353355 0
Relationship of DEEP mapping abnormalities (location and area involved) to abnormal voltage on standard voltage mapping during atrial fibrillation ablation procedure.
Timepoint [1] 353355 0
At initial AF ablation procedure.
Secondary outcome [2] 353359 0
Relationship of DEEP mapping abnormalities (location and area involved) to abnormal activation patterns (for example complex fractionated atrial electrograms or re-entrant activity) on activation mapping during atrial fibrillation ablation procedure.
Timepoint [2] 353359 0
At initial AF ablation procedure.

Key inclusion criteria
Recurrent Atrial Fibrillation ablation, referred for catheter ablation.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Unable to provide informed consent.
Pregnant women.

Study design
Natural history
Defined population
Statistical methods / analysis
Mean values and SDs will be calculated for normally distributed continuous variables; median and interquartile range for non-parametric data. Categorical data expressed will be expressed as percentages (ratio). Categorical data will be compared with a Fisher exact test or a chi-square test. Continuous data will be compared with the Student t test. A p value of <.05 will be considered significant. Kaplan-Meier curves for event-free survival will be constructed using the time to first AF recurrence. Comparison between both groups will be performed by log-rank statistics. Fifteen participants will be recruited from each of 5 international centres, giving 75 in total.

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 12296 0
John Hunter Hospital - New Lambton
Recruitment hospital [2] 12297 0
Lake Macquarie Private Hospital - Gateshead
Recruitment postcode(s) [1] 24488 0
2305 - New Lambton
Recruitment postcode(s) [2] 24489 0
2290 - Gateshead
Recruitment outside Australia
Country [1] 20978 0
United Kingdom
State/province [1] 20978 0
Country [2] 20979 0
State/province [2] 20979 0
Country [3] 20980 0
State/province [3] 20980 0
Country [4] 20981 0
State/province [4] 20981 0

Funding & Sponsors
Funding source category [1] 301043 0
Name [1] 301043 0
John Hunter Hospital Cardiology Department
Address [1] 301043 0
Level 3, John Hunter Hospital, Lookout Road, New Lambton, NSW 2305
Country [1] 301043 0
Primary sponsor type
John Hunter Hospital Cardiology Department
Level 3, John Hunter Hospital, Lookout Road, New Lambton, NSW 2305
Secondary sponsor category [1] 300640 0
Name [1] 300640 0
Address [1] 300640 0
Country [1] 300640 0

Ethics approval
Ethics application status
Ethics committee name [1] 301798 0
Hunter New England Human Research Ethics Committee
Ethics committee address [1] 301798 0
Locked Bag No 1 New Lambton NSW 2305
Ethics committee country [1] 301798 0
Date submitted for ethics approval [1] 301798 0
Approval date [1] 301798 0
Ethics approval number [1] 301798 0

Brief summary
In the proposed study, the treating electrophysiologist will use a new and more focused method to help him/her in identifying the pathological potentials that are responsible for initiation and maintenance of AF. Despite many efforts globally, there has been a lack of ability to find and prove the best targets for ablation outside the pulmonary veins for AF, which is of particular interest in improving the success of ablation for persistent AF. There is recent evidence for the DEEP method in mapping for VT procedures. The proposed method is based on a mechanistic concept that regions that participate in the initiation of AF will demonstrate significant decremental properties prior to block and reentry, when stressed by a closely coupled premature beat. This method simply requires some additional pacing and mapping of the response to this during the routine post-ablation waiting period while patients are already undergoing AF ablation.

In this study, mapping of DEEP will be performed to determine its feasibility in atrial tissue, and the presence of DEEP will be tested as a predictor of recurrence of AF during the follow-up period of 12 months. Areas of DEEP will also be compared in location and extent to abnormal voltage and complex signals seen on standard mapping (such as complex fractionated atrial electrograms and re-entrant areas). Fifteen participants will be recruited at each of 5 international centres for a total of 75 participants.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 88142 0
Dr Nicholas Jackson
Address 88142 0
John Hunter Hospital Cardiology department, Lookout Road, New Lambton. NSW. 2305.
Country 88142 0
Phone 88142 0
+61 2 49213000
Fax 88142 0
Email 88142 0
Contact person for public queries
Name 88143 0
Dr Nicholas Jackson
Address 88143 0
John Hunter Hospital Cardiology department, Lookout Road, New Lambton. NSW. 2305.
Country 88143 0
Phone 88143 0
+61 2 49213000
Fax 88143 0
Email 88143 0
Contact person for scientific queries
Name 88144 0
Dr Nicholas Jackson
Address 88144 0
John Hunter Hospital Cardiology department, Lookout Road, New Lambton. NSW. 2305.
Country 88144 0
Phone 88144 0
+61 2 49213000
Fax 88144 0
Email 88144 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
No other documents available
Summary results
No Results