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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Mapping of Atrial Arrhythmias Using High Spatial Resolution Mapping Catheters and the Rhythmia Mapping System
Scientific title
Mapping of Atrial Arrhythmias Using High Spatial Resolution Mapping Catheters and the Rhythmia Mapping System: Validation of Classical Entrainment, Activation and Pace Mapping Techniques using new technology
Secondary ID [1] 286477 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Atrial Tachycardia 294663 0
Atrial flutter 294664 0
Condition category
Condition code
Cardiovascular 294965 294965 0 0
Other cardiovascular diseases

Study type
Description of intervention(s) / exposure
To evaluate the resolution and accuracy of the Rhythmia mapping system and new high spatial resolution catheters in the mapping of atrial arrhythmias. The two novel high spatial resolution catheters called the IntellaTip-MiFi and IntellaMap-Orion have micro electrodes at the catheter tip with very narrow spacing between adjacent recording electrodes resulting in a 2-5 x increase in spatial resolution compared to standard mapping catheters. The IntellaTip MiFi catheters have 3 'micro' electrodes at the tip of the catheter with an inter-electrode distance of 0.8mm. The IntellaMap-Orion catheter has 64 individual micro electrodes with a 2.5mm inter-electrode spacing. Both catheters have a much smaller electrode size and narrower inter-electrode distance compared to the 3.4 to 5mm tipped mapping catheters that are currently available. The Rhythmia mapping system allows real-time automated signal analysis, which means electrical maps can be created in real-time as opposed to the time consuming off-line analysis that is required currently. The system uses an automated annotation algorithm that determines local activation time and builds a 3D activation map as each point is acquired. In theory the combination of the 2.5mm inter-electrode space IntellaMap-Orion basket catheter coupled with the automated electrogram annotation would allow a highly detailed activation map to be created in minimal time. Depending on the complexity of the patient's arrhythmia, the case make take approximately an hour. The detailed mapping will be performed by an experienced cardiologist. The outcome timepoint would be accurate identification of the arrhythmia circuit and site of focal activation.
Intervention code [1] 291562 0
Treatment: Devices
Intervention code [2] 291612 0
Diagnosis / Prognosis
Comparator / control treatment
Use of current standard catheters for mapping of atrial arrhythmias. Current electro anatomical mapping systems are limited by (1) point-by-point mapping data acquisition, (2) requiring a large number of mapping sites for high resolution (3–4 mm in areas of interest), and (3) the need to individually annotate the activation time at sites with complex electrograms (low amplitude potentials, double potentials, or fractionated electrograms) in scarred myocardium. In addition the mapping resolution of currently available mapping catheters is limited to around 3.5-5mm which is the size of the distal tip electrode. This means that important electrical information may hidden during mapping due to the poor spatial resolution of mapping catheters.
Control group

Primary outcome [1] 294721 0
1. No of accepted beats and electrograms
- The Rhythmia system is designed to automatically annotate cardiac electrograms. However, this system has not been clinically validated. A cardiologist trained in analyzing electrograms will review the electrograms manually. The number of points that require manual annotation to correct will be determined and a percentage of incorrect points determined
Timepoint [1] 294721 0
Accurate identification of the arrhythmia circuit or site of focal activation at completion of the mapping procedure.
Primary outcome [2] 294783 0
2. Mapping resolution between manual map versus automated map
Timepoint [2] 294783 0
Accurate identification of the arrhythmia circuit or site of focal activation at completion of the mapping procedure.
Secondary outcome [1] 313927 0
1. Mapping time
Timepoint [1] 313927 0
Accurate identification of the arrhythmia circuit or site of focal activation at completion of the mapping procedure.

Key inclusion criteria
Patients having mapping and ablation of atrial arrhythmias (focal atrial tachycardia and macro-reentrant atrial flutter).
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
1. Uncontrolled hypertension.
2. Known coagulopathy or thrombophilia
3. Inability to provide informed consent (e.g. people with an intellectual or mental impairment)
4. Women who are pregnant
5. Children and/or young people (ie. <18 years)

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
All patients with documented symptomatic atrial tachycardia or atrial flutter will be screened and recruited to participate in the study.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
This is not a randomised study
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Values will be expressed as range and median or mean±SD. Nonparametric (Mann-Whitney U) tests will be used to compare the projection distance for surface electrogram, mapping time, number of accepted beats, number of accepted electrograms, and mapping resolution between the Manual Map Mode and the Auto Map Mode.

This research proposal seeks to explore the difference in spatial resolution for both activation and pacemapping for atrial arrhythmias and accuracy of entrainment mapping between standard catheters and the new IntelliMap Orion catheters. The catheters will routinely collect over 200-300 activation points in each patient to create the 3D activation maps. As a consequence, this project will acquire over 4000-6000 sampling measures (20 patients, 200-300 activation points per patient) with which to assess the difference between the standard catheters and the new catheters.

Basing sample size estimation on the number of activation points rather than the number of participants, approx. 1000 activation points are likely to be needed to detect a clinical meaningful difference of 20% in activation times, at a power of 90% and error of 0.05.

In addition, previous work in this field have been able to demonstrate clear association with small participant numbers. Key studies involving characterization of focal atrial tachycardias which were performed at Royal Melbourne Hospital, the sample size has involved approximately 10 patients. Furthermore, studies will have defined atrial flutter circuits have also involved small numbers of less than 10 participants.

Recruitment status
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] 3656 0
Royal Melbourne Hospital - City campus - Parkville
Recruitment postcode(s) [1] 9488 0
3050 - Royal Melbourne Hospital

Funding & Sponsors
Funding source category [1] 291041 0
Self funded/Unfunded
Name [1] 291041 0
Address [1] 291041 0
Country [1] 291041 0
Primary sponsor type
Royal Melbourne Hospital
300 Grattan St
Victoria 3050
Secondary sponsor category [1] 289724 0
Name [1] 289724 0
Address [1] 289724 0
Country [1] 289724 0

Ethics approval
Ethics application status
Ethics committee name [1] 292625 0
Melbourne Health
Ethics committee address [1] 292625 0
300 Grattan St
Victoria 3050
Ethics committee country [1] 292625 0
Date submitted for ethics approval [1] 292625 0
Approval date [1] 292625 0
Ethics approval number [1] 292625 0

Brief summary
Activation, Entrainment and Pace mapping techniques has been the mainstay of the catheter based mapping and ablation of all atrial arrhythmias. The original studies describing these mapping techniques were performed almost two decades ago. These studies were performed using fluoroscopy alone without the aid of a 3D electroanatomical mapping system. Indeed all published mapping and entrainment studies have been performed using catheters with a large (4mm or 8mm) distal tip of the roving mapping catheter. These studies are yet to be repeated using the newly available catheter technology. Indeed there is no data on the accuracy of activation, entrainment and pace mapping using these ‘new generation’ of mapping catheters with small micro electrodes and narrow bipolar spacing. Hence the aim of this study is to perform detailed activation, entrainment and pace mapping in a variety of atrial arrhythmias in order to validate the classical mapping criteria and techniques using these new catheters.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 56302 0
Prof Jonathan Kalman
Address 56302 0
Department of Cardiology
Royal Melbourne Hospital
300 Grattan St
Victoria 3050
Country 56302 0
Phone 56302 0
Fax 56302 0
Email 56302 0
Contact person for public queries
Name 56303 0
Dr Bhupesh Pathik
Address 56303 0
Department of Cardiology
Royal Melbourne Hospital
300 Grattan St
Victoria 3050
Country 56303 0
Phone 56303 0
Fax 56303 0
Email 56303 0
Contact person for scientific queries
Name 56304 0
Dr Bhupesh Pathik
Address 56304 0
Department of Cardiology
Royal Melbourne Hospital
300 Grattan St
Victoria 3050
Country 56304 0
Phone 56304 0
Fax 56304 0
Email 56304 0

No information has been provided regarding IPD availability
Summary results
No Results