Atrial Synchrony Evaluation of Bachmann Bundle Pacing in Sick Sinus Syndrome

Shiyan City Renmin Hospital72 enrolled

Overview

This is a prospective, randomized study to compare the effects of Bachmann bundle pacing (BBP) versus conventional right atrial appendage (RAA) pacing on atrial electromechanical synchrony in patients with sick sinus syndrome (SSS). The study utilizes two-dimensional speckle tracking imaging (2D-STI) to assess improvements in cardiac function and synchrony, aiming to determine a more optimal pacing site for SSS patients.

Sick sinus syndrome (SSS) is a common indication for permanent pacemaker implantation. Conventional right atrial appendage (RAA) pacing, however, is non-physiological and may lead to atrial conduction delays, atrial remodeling, and an increased risk of atrial fibrillation. Bachmann bundle pacing (BBP) is emerging as a more physiological pacing strategy that may correct atrial conduction delays and improve electromechanical synchronization. This study prospectively enrolled and randomized 72 patients with SSS to receive either BBP or RAA pacing. The primary objective is to evaluate the differences in atrial synchrony, cardiac function, and pacing parameters between the two groups at baseline, 1-month, and 3-month follow-ups, using electrocardiography and two-dimensional speckle tracking imaging (2D-STI). The study aims to provide evidence for BBP as a superior treatment option for improving long-term outcomes in SSS patients.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

Conditions

Sick Sinus Syndrome

Interventions

Bachmann Bundle PacingDEVICE

Implantation of a permanent pacemaker system. The atrial lead (Medtronic 3830 active electrode) is surgically positioned and fixed in the Bachmann bundle region, located at the angle between the superior vena cava and the atrium in the mid-posterior position of the high atrial septum. Successful placement is confirmed by achieving a P-wave width shortening of at least 30ms compared to the preoperative P-wave. The ventricular lead is positioned in the mid-to-lower portion of the ventricular septum. Pacing parameters are measured and confirmed to be good.

Right Atrial Appendage PacingDEVICE

Implantation of a permanent pacemaker system using the conventional technique. The atrial active electrode is surgically positioned and fixed in the right atrial appendage. The ventricular lead is placed in the mid-to-lower portion of the ventricular septum. Pacing parameters (sensing \> 2.0mV; impedance between 300 to 1000Ω; threshold \< 1.5mV) are confirmed to be good.

Eligibility

Sex: ALLMin age: 30 YearsMax age: 90 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Meets diagnostic criteria for sick sinus syndrome (e.g., persistent sinus bradycardia \<50 bpm, sinus arrest, sinoatrial block, or tachy-brady syndrome). * Age between 30 and 90 years. * Has not taken any other antiarrhythmic drugs within one month prior to enrollment. * Has not participated in any other related clinical trials. * Voluntarily signs the informed consent form. Exclusion Criteria: * Patients with severe primary diseases causing unstable vital signs (e.g., severe circulatory, digestive, or neurological system diseases). * Patients with a history of recurrent syncope, Adams-Stokes syndrome, severe bradycardia (lowest sinus rhythm \<30 bpm), or long RR interval \>3s. * Pregnant or lactating women. * Patients with mental illness.

Locations (1)

Beijing Anzhen Hospital, Capital Medical University

Shiyan, Hubei, China

Outcomes

Primary Outcomes

Change in Inter-atrial Electromechanical Delay (Inter AEMD)

Measured by two-dimensional speckle tracking imaging (2D-STI) as the time difference between the onset of the P-wave on the electrocardiogram (ECG) and the peak longitudinal strain of the lateral walls of the right and left atria. A smaller value indicates better inter-atrial synchrony.