The Relationship between Intracardiac Atrial Sensing Values and Atrial High-rate Episodes in Patients With Permanent Pacemakers Implanted due to Sick Sinus Syndrome

Aim: An increase in fibrosis and collagen in the atrium and sinus node tissues constitutes the basic pathophysiology of sick sinus syndrome (SSS). We aimed to investigate the relationship between P-wave sensing values and atrial high rate episodes (AHRE) in patients with dual-chamber (DDDR) pacemakers implanted due to SSS. Methods: Patients with DDDR pacemakers implanted due to SSS between 2011 and 2019 were included in our retrospective cohort study. The patients were called for a visit and pacemaker controls were performed. The study population was divided into two groups according to the development of AHRE. Results: At least one AHRE episode was detected in 51.7% of participants. Left atrial (LA) diameters were increased in the AHRE+ group (p<0.01). P-wave sensing values were significantly lower in the AHRE+ group (p=0.01). LA diameter [hazard ratio (HR): 1.10, 95% (1.04-1.18), p<0.01] and P-wave sensing values [HR: 0.74, confidence interval 95% (0.57-0.95) p=0.02] were determined as independent predictors of AHRE. Conclusion: Our study demonstrated that LA diameter and P-wave sensing values were found to be independent predictors of AHRE development. Lower initial P-wave sensing values seem to be an important risk factor for AHRE development in this patient group.