Background:

In patients requiring dual-chamber pacemaker implantation, optimal atrial lead position remains a matter of debate. While most centers prefer implantation in the right atrial appendage (RAA-P) position, Bachman bundle pacing (BB-P) is often recommended because of its speculated beneficial impact on atrial conduction characteristics. However, data investigating clinical outcomes in these patients is still rare.

Methods:

To evaluate this issue, in this retrospective single-center study, a clinical follow-up including available echocardiography findings in 301 consecutive patients (age 76±10 years, 48.3% female; RAA-P n=132 vs. BB-P n=169) scheduled for dual-chamber implantation was analyzed. 

Results:

During follow-up, incidence of atrial fibrillation remained similar in both groups (BB-P: 38.2% versus RAA-P: 34.5%, p=0.530). Furthermore, left ventricular functional parameters including left ventricular ejection fraction (BB-P: 58% versus RAA-P: 57%, p=0.827) and incidence of diastolic dysfunction (BB-P: 84% versus RAA-P: 82,7%, p=0.758) as well as rate of left atrial dilatation (BB-P: 21.9% versus RAA-P: 12.1 %, p=0.167)  were not affected by atrial lead position. However, stimulated P-waves were significantly shorter in BB-P (BB-P: 133±24ms versus RAA-P: 140±23ms; p=0.031). During follow-up, this was associated with a reduced incidence of right atrial dilatation (BB-P: 28.5% versus RAA-P: 35.0%, p=0.027) indicating beneficial impacts on right atrial remodeling.

Conclusion:

In patients requiring dual-chamber implantation, the position of the atrial lead seems not to affect left ventricular function parameters. However, Pacing in BB-P seems to have a favorable impact on cardiac conduction with consequent impact on right atrial remodeling. Further studies need to investigate the impact of pacing in BB-P on clinical outcomes.