Atrial Synchrony Evaluation of Bachmann Bundle Pacing in Sick Sinus Syndrome

Clinical Study on the Application of Two-dimensional Speckle Tracking Imaging to Evaluate the Atrial Synchrony of Bachmann Bundle Pacing in Patients With Sick Sinus Syndrome

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.

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.