INTRODUCTION
Sudden cardiac death (SCD) is the most common cause of death in patients with end-stage renal disease (ESRD) on hemodialysis (HD) [1]. Two-thirds of these sudden deaths are due to fatal arrhythmias, accounting for 26% of overall mortality [2-5]. Historically, ventricular arrhythmias (VA) have been thought to be the primary driver of SCD in this population. However, emerging data suggest that bradyarrhythmias and asystole, rather than VA, may be the major cause of arrhythmia-related death in ESRD patients [6-7]. Beyond arrhythmia etiology itself, temporal relationships have been demonstrated between arrhythmia burden, SCD, and HD schedule, such that the long-interdialytic period (72-hours, LIDP) has been associated with higher rates of arrhythmic events, as well as increased hospitalization rates and mortality [6-11]. Thus, there is a crucial need for clarification of both tachy- and bradyarrhythmia etiology, prevalence, and contribution to mortality in ESRD patients on HD, while also defining the temporal relationships between interdialytic period duration and arrhythmia risk. Cardiac implantable electronic devices (CIEDs) offer a unique and underutilized source of rhythm data analysis which might be used to investigate the differences in arrhythmia risk and timing between ESRD patients on HD and controls. To our knowledge, this is the first study systematically evaluating the arrhythmia burden in ESRD patients with CIEDs compared to control patients with CIEDs.