Trial Review

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Trial registered on ANZCTR


Registration number
Help: Registration number
ACTRN12626000923369
Ethics application status
Help: Ethics application status
Approved
Date submitted
Help: Date submitted
11/07/2026
Date registered
Help: Date registered
28/07/2026
Date last updated
Help: Date last updated
28/07/2026
Date data sharing statement initially provided
Help: Data sharing statement date
28/07/2026
Type of registration
Help: Type of registration
Retrospectively registered

Titles & IDs
Public title
Comparing two atrial pacemaker lead positions, Bachmann's bundle versus the right atrial appendage, and their effects on electrical conduction between the heart's upper chambers and on heart pressures and blood flow (haemodynamics), in adults receiving a pacemaker for sinus node dysfunction (a slow or unreliable natural heartbeat).
Scientific title
The effect of Bachmann's bundle pacing compared with right atrial appendage pacing on interatrial conduction delay, invasive haemodynamics and atrial strain in adults with sinus node dysfunction requiring permanent dual-chamber pacing: a prospective non-randomised cohort pilot study.
Additional trial identifiers [1] 317879 0
2025/STE04665
Universal Trial Number (UTN)
Trial acronym
Related trial records

Health condition
Health condition(s) studied:
sinus node dysfunction 342818 0
atrial fibrillation 342819 0
pacemakers 342820 0
Condition category
Condition code
Cardiovascular 338939 338939 0 0
Other cardiovascular diseases

Intervention/exposure
Study type
Interventional
Description of the intervention or exposure
Description of the intervention:

Bachmann's bundle pacing group. The atrial lead (Medtronic 3830) is actively fixed at the Bachmann's bundle region (SVC-RA junction) using the Lustgarten technique, as standard care. During implantation, a temporary dual-atrial configuration is created by transiently positioning the right ventricular lead in the right atrial appendage for approximately 10 minutes, with correct and precise positioning confirmed on fluoroscopy. While in this configuration the participant undergoes two study-specific measurements: focused intraprocedural transthoracic echocardiography (apical 4-chamber, 2-chamber and RV-focused views for strain and interatrial delay), and right heart catheterisation via the existing central venous access. The Swan-Ganz catheter is advanced into the right atrium, right ventricle and pulmonary artery; pulmonary capillary wedge pressure is obtained, and cardiac output is measured by triplicate thermodilution. The right ventricular lead is then repositioned to the right ventricle to complete standard dual-chamber implantation.

The pacing approach is determined clinically by the treating operator and technique rather than allocated by the study; participants are grouped according to the technique they receive as standard care.

Schedule and duration: a single index implantation procedure, followed by scheduled study visits at 6 and 12 months. Follow-up visits comprise pacemaker interrogation with measurement of interatrial conduction delay, targeted transthoracic echocardiography for left atrial strain and diastolic function, device-counter atrial fibrillation burden and atrial tachyarrhythmia detection, NYHA class, and the AFEQT questionnaire. Follow-up is 12 months per participant.
Intervention code [1] 334812 0
Diagnosis / Prognosis
Description of the comparator or control
Arm 2, right atrial appendage pacing cohort. The comparator is standard dual-chamber pacemaker implantation with the atrial lead fixed at the right atrial appendage (active or passive fixation) and active fixation of the ventricular lead, following routine institutional protocol. These participants undergo no additional study-specific procedures: no right heart catheterisation and no intraprocedural echocardiography. They are then observed on the same 6- and 12-month follow-up schedule as Arm 1.
Control group
Active

Outcomes
Primary outcome [1] 346167 0
Interatrial conduction delay (IACD), in milliseconds.
Timepoint [1] 346167 0
6 and 12 months post-implantation
Secondary outcome [1] 464869 0
Pulmonary capillary wedge pressure
Timepoint [1] 464869 0
Intra-operatively during pacemaker implantation (single timepoint)
Secondary outcome [2] 464870 0
Cardiac output
Timepoint [2] 464870 0
Intra-operatively during pacemaker implantation (single timepoint)
Secondary outcome [3] 464871 0
Left atrial reservoir strain
Timepoint [3] 464871 0
6 and 12 months post-implantation
Secondary outcome [4] 464872 0
Atrial fibrillation burden
Timepoint [4] 464872 0
6 and 12 months post implantation
Secondary outcome [5] 464873 0
Incidence of atrial tachyarrhythmias
Timepoint [5] 464873 0
6 and 12 months post implantation
Secondary outcome [6] 464874 0
Procedure-related adverse events, such as: haemorrhage; haemoptysis; induced ventricular tachycardia; pulmonary artery perforation; worsening tricuspid regurgitation; arrhythmia provoked by catheter manipulation; catheter-related thrombosis or infection; skin irritation from ultrasound gel; and breach of the sterile field during intra-operative imaging. Events related to the pacemaker implantation itself (lead dislodgement, pneumothorax, cardiac perforation or tamponade, pocket haematoma, device infection) will also be recorded, though these arise from standard care rather than the study-specific procedures. This is a composite safety outcome; each event is recorded individually and reported descriptively as counts, severity and relationship to the procedure.
Timepoint [6] 464874 0
From implantation through to 12 months.

Eligibility
Key inclusion criteria
Adults with sinus node dysfunction requiring a permanent pacemaker with an atrial lead. Sinus node dysfunction is defined by documented sinus pauses (sinus arrest or sinoatrial exit block), tachy-brady syndrome, or chronotropic incompetence. Participants must be aged 18 years or older and able to give written informed consent.
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Healthy volunteers
No
Key exclusion criteria
History of permanent atrial fibrillation; atrioventricular block in the absence of sinus node dysfunction; planned atrioventricular nodal ablation; spontaneous resting sinus rate above 85 bpm; pregnancy; anticipated life expectancy under one year.

Study design
Purpose of the study
Diagnosis
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis
Target sample size 40, with 20 per group. The sample size was set on the primary outcome, interatrial conduction delay. Drawing on Suzuki et al. and Yoshimoto et al., an expected between-group difference of approximately 23 ms with a pooled standard deviation of 12 ms gives over 90% power at a two-sided alpha of 0.05 with 20 per group. As a pilot, the aim is to generate preliminary estimates of effect size and variability to inform the design and power of a future randomised trial rather than to provide confirmatory efficacy testing. Continuous outcomes will be summarised as mean and standard deviation with 95% confidence intervals; pre-specified baseline differences (age, atrial size, prior atrial fibrillation, baseline P-wave duration or IACD) will be handled by covariate adjustment in regression.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
30/04/2026
Date of last participant enrolment
Anticipated
30/01/2027
Actual
Date of last data collection
Anticipated
30/01/2028
Actual
Sample size
Target
40
Accrual to date
4
Final
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment hospital [1] 29820 0
Royal North Shore Hospital - St Leonards
Recruitment hospital [2] 29821 0
North Shore Private Hospital - St Leonards
Recruitment postcode(s) [1] 46173 0
2065 - St Leonards

Funding & Sponsors
Funding source category [1] 322417 0
Charities/Societies/Foundations
Name [1] 322417 0
Heart Research Australia Project Grant
Country [1] 322417 0
Australia
Primary sponsor type
Government body
Name
Northern Sydney Local Health District
Address
Country
Australia
Secondary sponsor category [1] 325341 0
Hospital
Name [1] 325341 0
North Shore Private Hospital
Address [1] 325341 0
Country [1] 325341 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 320914 0
Northern Sydney Local Health District Human Research Ethics Committee
Ethics committee address [1] 320914 0
Ethics committee country [1] 320914 0
Australia
Date submitted for ethics approval [1] 320914 0
10/09/2025
Approval date [1] 320914 0
09/12/2025
Ethics approval number [1] 320914 0
2025/ETH01917

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 152054 0
Dr Karin Chia
Address 152054 0
Cardiology Department, Royal North Shore Hospital, Reserve Road, St Leonards NSW 2065.
Country 152054 0
Australia
Phone 152054 0
+61 2 9463 2500
Fax 152054 0
Email 152054 0
[email protected]
Contact person for public queries
Name 152055 0
Bernard Chan
Address 152055 0
Cardiology Department, Royal North Shore Hospital, Reserve Road, St Leonards NSW 2065.
Country 152055 0
Australia
Phone 152055 0
+61 2 9926 7111
Fax 152055 0
Email 152055 0
[email protected]
Contact person for scientific queries
Name 152056 0
Bernard Chan
Address 152056 0
Cardiology Department, Royal North Shore Hospital, Reserve Road, St Leonards NSW 2065.
Country 152056 0
Australia
Phone 152056 0
+61 2 9926 7111
Fax 152056 0
Email 152056 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No


What supporting documents are/will be available?

No Supporting Document Provided


Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.