Temporal distribution of arrhythmic events in chronic kidney disease: Highest incidence in the long interdialytic period.

Background: Chronic kidney disease (CKD) patients undergoing hemodialysis (HD) have a high risk of sudden cardiac death (SCD). A unique risk factor may be a longer interval between HD sessions (interdialytic period). Inherent in conventional HD (thrice-weekly) are two 48-hour short breaks (SIDP) and one 72-hour long break (LIDP) between HD sessions.

Objective: We used an implantable cardiac monitor (ICM) to define the incidence and timing of significant arrhythmias in an HD population.

Methods: Fifty CKD patients undergoing HD with left ventricular ejection fraction >35% had an ICM inserted, with intensive follow-up to record SCD events and predefined bradyarrhythmias and tachyarrhythmias.

Results: Mean age of the patients was 67 ± 11 years; 72% were male, and the mean follow-up was 18 ± 4 months. There were 8 unexpected SCDs (16%), all during the LIDP. The terminal event was severe bradycardia with asystole in each recorded case. No episodes of polymorphic ventricular tachycardia (VT) occurred. A total of 7686 arrhythmia events were recorded in 43 patients (86%), including bradycardia in 15 patients (30%), sinus arrest in 14 (28%), second-degree atrioventricular block in 4 (8%), nonsustained VT in 10 (20%), and new-onset paroxysmal atrial fibrillation in 14 (28%). The LIDP was the highest-risk period for all arrhythmias (P < .001). The arrhythmia event rate per hour was greatest during the first pre-HD period of the week compared with any other peri-HD period (P < .001).

Conclusion: Risk of SCD and significant arrhythmias is greatest during the LIDP. SCD was attributable to severe bradycardia and asystole. Interventions to prevent this type of SCD or shorten the LIDP deserve further evaluation.

Clinical Trial Registration Information: URL: https://www.anzctr.org.au (Unique identifier: ACTRN12613001326785).