Introduction

Atrial High Rate Episodes (AHRE) are asymptomatic flurries of increased atrial rates detected by a cardiac implanted electronic device (CIED) in patients without history of clinical atrial fibrillation (AF). They are common, detected in around a third of hypertensive over 65-year-olds within the first 2.5 years of pacemaker implant (1). Their clinical significance is unclear. Should AHRE be seen as a precursor to AF? Do they contribute to thromboembolic risk? And if so, should we offer anticoagulation to these patients even in the absence of surface ECG confirmation of AF?