AUTONOMIC AND VASCULAR FUNCTION CHARACTERISTICS IN PATIENTS WITH ATRIAL HIGH RATE EPISODES

Introduction Patients who experience frequent atrial high rate episodes (AHREs), recorded on implantable cardiac devices, are at an increased risk of stroke and systemic embolism. Increased duration of AHRE is related to higher risk of thromboembolic event. The underlying pathophysiology is unclear; however, autonomic and/or endothelial dysfunction may contribute. We tested the hypothesis that patients with high AHRE burden have worse autonomic and vascular function compared to patients with low AHRE burden. Methods We studied 44 patients split in two groups: high AHRE burden (longest AHRE ≥ 24 hours; n = 22) and low AHRE burden (longest AHRE Results FMD was higher in the low AHRE burden group compared to high AHRE group (5.5% [95% confidence interval (CI):3.4–7.6] vs 3.1% [95% CI:1.9–6.2]; p=0.04) (table 1). Mean heart rate (p Conclusion Endothelium-dependent FMD is impaired in patients with high AHRE burden, while HRV derived indices of autonomic function were not affected by AHRE burden. Endothelial dysfunction may play an important role in the adverse outcomes seen in patients who experience frequent AHRE. Conflict of Interest None