Prospective Cohort Study of Bachmann Bundle Versus Right Atrial Appendage Pacing: Impact on Atrial Cardiomyopathy Evaluated by Echocardiographic Parameters and Clinical Outcome (BRAVE)

The goal of this observational study is to evaluate the impact of different atrial pacing sites-Bachmann's bundle pacing versus right atrial appendage pacing-on the development and progression of atrial cardiomyopathy in patients diagnosed with sick sinus syndrome who are undergoing permanent pacemaker implantation.

Study Overview

• Status: Recruiting
• Conditions: Sick Sinus Syndrome
• Intervention / Treatment: Procedure: Right Atrial Appendage Pacing; Procedure: Bachmann Bundle Pacing

Detailed Description

Previous studies have reported that conventional Right Atrial Appendage pacing is associated with delayed atrial activation time. A higher burden of atrial pacing at this site has been linked to an increased incidence of atrial fibrillation and atrial tachycardia. Furthermore, structural and functional deterioration of the atria-specifically Left Atrial dilation and reduced left atrial strain-has been observed in patients with a high percentage of Right Atrial Appendage pacing. These changes are known to accelerate the progression of atrial cardiomyopathy, potentially leading to adverse long-term clinical outcomes.

To address these limitations, Bachmann Bundle Pacing has emerged as a promising alternative pacing site. The Bachmann bundle is a major atrial myoarchitecture connecting the right and left atria. Pacing at this site is expected to facilitate interatrial conduction, thereby restoring interatrial synchrony and mitigating interatrial block. Prior research indicates that pacing at the Bachmann bundle is associated with a reduced incidence of atrial fibrillation and atrial tachycardia, suggesting distinct benefits regarding atrial electrophysiological outcomes. However, existing studies have primarily focused on electrophysiological parameters, such as arrhythmia incidence. Consequently, the impact of Bachmann Bundle Pacing on atrial structural and functional remodeling remains to be clearly elucidated.

Therefore, this study is designed as a single-center cohort study enrolling a total of 200 subjects (100 prospective and 100 retrospective). We will analyze echocardiographic parameters over a 12-month period following pacemaker implantation. By comprehensively analyzing imaging parameters (left atrial/right atrial strain and volume changes assessed via echocardiography) and clinical outcomes (atrial arrhythmias, heart failure hospitalization, and mortality), this study aims to investigate the differential effects of Bachmann Bundle Pacing versus Right Atrial Appendage pacing on the development and progression of atrial cardiomyopathy.

• Study Type: Observational
• Enrollment (Estimated): 200

Contacts and Locations

• Study Contact: Name: Kim Ju Won, Clinical assistant professor, Ph.D; Phone Number: 82+ 10-2079-8154; Email: abcd186a@naver.com
• Study Contact Backup: Name: Lee Ju Hee, Clinical Research Nurse, Bachelor; Phone Number: 82+ 10-7180-3357; Email: phacyde12@gmail.com

Study Locations

• South Korea
  • Seoul
    • Seoul, Seoul, South Korea, 06351
      • Recruiting
      • Samsung Medical Center
      • Contact: Kim Ju Won, Clinical assistant professor, Ph.D; Phone Number: 82+ 2-3410-3419; Email: abcd186a@naver.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients who presented to Samsung Medical Center, were diagnosed with Sick Sinus Syndrome, and underwent de novo permanent pacemaker or implantable cardioverter-defibrillator implantation based on clinical indications.

Description

Inclusion Criteria:

• Patients aged 19 years or older
• Patients diagnosed with sick sinus syndrome who are scheduled for de novo implantation of a permanent pacemaker or permanent implantable cardioverter-defibrillator
• Patients or their legal representatives who voluntarily consent to the access of medical records and study data throughout the entire research period

Exclusion Criteria:

• Patients with persistent or permanent AF
• Patients with a life expectancy of less than one year due to other comorbidities
• Pregnant or breastfeeding women
• Patients who refuse active treatment

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Right Atrial Appendage Pacing	Procedure: Right Atrial Appendage Pacing; Atrial lead positioned in the right atrial appendage
Bachmann Bundle Pacing	Procedure: Bachmann Bundle Pacing; Atrial lead positioned in the bachmann bundle branch

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Structural echocardiographic parameters of the left atrium	LA Volume Index measured as mL/m^2	6 and 12 months after pacemaker implantation
Functional echocardiographic parameters of the left atrium	Reservoir Strain (%), Conduit Strain (%), Contraction Strain (%)	6 and 12 months after pacemaker implantation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Structural echocardiographic parameters of the left ventricle	LV End-Diastolic Diameter(mm), LV End-Systolic Diameter(mm)	6 and 12 months after pacemaker implantation
Functional echocardiographic parameters of the left ventricle	LV Ejection Fraction (%), Global Longitudinal Strain (%)	6 and 12 months after pacemaker implantation
Mitral and tricuspid regurgitation volume	as mL per beat	6 and 12 months after pacemaker implantation
Structural echocardiographic parameters of the right atrium	RA Volume Index (mL/m^2)	6 and 12 months after pacemaker implantation
Functional echocardiographic parameters of the right atrium	RA Reservoir Strain (%), RA Conduit Strain (%), RA Contraction Strain (%)	6 and 12 months after pacemaker implantation
ECG parameters	PR interval (ms), QRS duration (ms), P wave duration (ms), QTC (ms)	6 and 12 months after pacemaker implantation
Average heart rate	bpm	6 and 12 months after pacemaker implantation
Heart rate distribution	percentage (%)	6 and 12 months after pacemaker implantation
Pacing burden	percentage (%)	6 and 12 months after pacemaker implantation
Atrial fibrillation burden	percentage (%)	6 and 12 months after pacemaker implantation
atrial fibrillation occurrence	count	6 and 12 months after pacemaker implantation
NTproBNP	pg/ml	6 and 12 months after pacemaker implantation
Procedure-related complications	count	6 and 12 months after pacemaker implantation
Pacemaker/Implantable cardioverter defibrillator parameters	Threshold (V)	6 and 12 months after pacemaker implantation
Pacemaker/Implantable cardioverter defibrillator parameters	longevity (year)	6 and 12 months after pacemaker implantation
Cardiac mortality	count	6 and 12 months after pacemaker implantation
All-cause mortality	count	6 and 12 months after pacemaker implantation
Patient's functional status	NYHA class I~IV	6 and 12 months after pacemaker implantation
hospitalization due to heart failure	count	6 and 12 months post-procedure
re-admission due to any cause	count	6 and 12 months post-procedure
Cerebrovascular event	count	6 and 12 months post-procedure

Collaborators and Investigators

• Sponsor: Samsung Medical Center

Publications and helpful links

General Publications

• Bailin SJ, Adler S, Giudici M. Prevention of chronic atrial fibrillation by pacing in the region of Bachmann's bundle: results of a multicenter randomized trial. J Cardiovasc Electrophysiol. 2001 Aug;12(8):912-7. doi: 10.1046/j.1540-8167.2001.00912.x.
• Infeld M, Nicoli CD, Meagher S, Tompkins BJ, Wayne S, Irvine B, Betageri O, Habel N, Till S, Lobel J, Meyer M, Lustgarten DL. Clinical impact of Bachmann's bundle pacing defined by electrocardiographic criteria on atrial arrhythmia outcomes. Europace. 2022 Oct 13;24(9):1460-1468. doi: 10.1093/europace/euac029.
• Lustgarten DL, Habel N, Sanchez-Quintana D, Winget J, Correa de Sa D, Lobel R, Thompson N, Infeld M, Meyer M. Bachmann bundle pacing. Heart Rhythm. 2024 Sep;21(9):1711-1717. doi: 10.1016/j.hrthm.2024.03.1786. Epub 2024 Mar 27. No abstract available.
• Martens P, Deferm S, Bertrand PB, Verbrugge FH, Ramaekers J, Verhaert D, Dupont M, Vandervoort PM, Mullens W. The Detrimental Effect of RA Pacing on LA Function and Clinical Outcome in Cardiac Resynchronization Therapy. JACC Cardiovasc Imaging. 2020 Apr;13(4):895-906. doi: 10.1016/j.jcmg.2019.04.022. Epub 2019 Jul 17.
• Roithinger FX, Abou-Harb M, Pachinger O, Hintringer F. The effect of the atrial pacing site on the total atrial activation time. Pacing Clin Electrophysiol. 2001 Mar;24(3):316-22. doi: 10.1046/j.1460-9592.2001.00316.x.
• De Sisti A, Leclercq JF, Stiubei M, Fiorello P, Halimi F, Attuel P. P wave duration and morphology predict atrial fibrillation recurrence in patients with sinus node dysfunction and atrial-based pacemaker. Pacing Clin Electrophysiol. 2002 Nov;25(11):1546-54. doi: 10.1046/j.1460-9592.2002.01546.x.
• Elkayam LU, Koehler JL, Sheldon TJ, Glotzer TV, Rosenthal LS, Lamas GA. The influence of atrial and ventricular pacing on the incidence of atrial fibrillation: a meta-analysis. Pacing Clin Electrophysiol. 2011 Dec;34(12):1593-9. doi: 10.1111/j.1540-8159.2011.03192.x. Epub 2011 Aug 7.
• Bradshaw PJ, Stobie P, Knuiman MW, Briffa TG, Hobbs MS. Trends in the incidence and prevalence of cardiac pacemaker insertions in an ageing population. Open Heart. 2014 Dec 10;1(1):e000177. doi: 10.1136/openhrt-2014-000177. eCollection 2014.
• Honarbakhsh S, Hunter L, Chow A, Hunter RJ. Bradyarrhythmias and pacemakers. BMJ. 2018 Mar 15;360:k642. doi: 10.1136/bmj.k642. No abstract available.
• Kusumoto FM, Schoenfeld MH, Barrett C, Edgerton JR, Ellenbogen KA, Gold MR, Goldschlager NF, Hamilton RM, Joglar JA, Kim RJ, Lee R, Marine JE, McLeod CJ, Oken KR, Patton KK, Pellegrini CN, Selzman KA, Thompson A, Varosy PD. 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2019 Aug 20;140(8):e382-e482. doi: 10.1161/CIR.0000000000000628. Epub 2018 Nov 6. No abstract available.

Study record dates

Study Major Dates

• Study Start (Actual): December 9, 2025
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: January 14, 2026
• First Submitted That Met QC Criteria: January 14, 2026
• First Posted (Actual): January 22, 2026

Study Record Updates

• Last Update Posted (Actual): January 22, 2026
• Last Update Submitted That Met QC Criteria: January 14, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: bachmann bundle pacing
• Additional Relevant MeSH Terms: Cardiac Conduction System Disease; Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Heart Block; Arrhythmia, Sinus; Pathological Conditions, Signs and Symptoms; Sick Sinus Syndrome
• Other Study ID Numbers: SMC2025-10-106; KCT0011382 (Other Identifier: Korea National Institute of Health)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No