Association of Bradycardia and Asystole Episodes with Dialytic Parameters: An Analysis of the Monitoring in Dialysis (MiD) Study

Abstract

Background Bradycardia and asystole events are common among patients treated with maintenance hemodialysis. However, triggers of these events in patients on maintenance hemodialysis (HD), particularly during the long interdialytic period when these events cluster, are uncertain. Methods The Monitoring in Dialysis Study (MiD) enrolled 66 patients on maintenance HD who were implanted with loop recorders and followed for 6 months. We analyzed associations of pre-dialysis laboratory values with clinically significant bradyarrhythmia or asystole (CSBA) during the 12 hours prior to an HD session. Associations with CSBA were analyzed with mixed effect models. Adjusted negative binomial mixed-effect regression was used to estimate incidence rate ratios (IRR) for CSBA. We additionally evaluated associations of CSBA at any time during follow-up with time-averaged dialytic and laboratory parameters as well associations of peri-dialytic parameters with occurrence of CSBA from the start of one HD session to the beginning of the next. Results There were 551 CSBA which occurred in the last 12 hours of the interdialytic interval preceding 100 HD session in 12.1% of patients and 1475 CSBA events in 22.7% of patients overall. We did not identify significant associations between dialytic parameters or serum electrolytes and CSBA in the last 12 hours of the interdialytic interval in adjusted analyses. Median time-averaged ultrafiltration rate was significantly higher in individuals without CSBA (9.8 vs. 8, p=0.04). Use of dialysate sodium concentrations ≤135 (vs. 140) mEq/L was associated with a reduced risk of CSBA from the start of one session to the beginning of next. Conclusions Although a few factors had modest associations with CSBA in some analyses, we did not identify any robust associations of modifiable parameters with CSBA in the MiD Study. Further investigation is needed to understand the high rates of arrhythmia in the hemodialysis population.

Chronic Kidney Disease Induces Proarrhythmic Remodeling

“…29 Several other recent studies also indicate a clinically significant relationship between renal dysfunction and bradyarrythmias in humans, showing that CKD and end-stage renal disease patients undergoing continuous cardiac monitoring exhibit intermittent episodes of sinus bradycardia, AV node block, long pauses, and asystole. 53–55 Interestingly, although we observed progressive AV block in CKD mice during episodes of SCD, we found no increase in AV delay or apparent underlying structural changes to the AV node in isolated hearts from CKD animals, suggesting that fluctuations in blood electrolytes or autonomic tone may play a role in CKD-associated cardiac conduction abnormalities in vivo.…”

Listening to the Rhythm of Arrhythmias Among Patients Maintained on Hemodialysis

“…The present secondary analysis of the MiD study in this issue of Kidney Medicine by Soomro et al 6 introduces another possible layer to the temporal story of cardiac arrhythmias in patients receiving intermittent hemodialysis—the possible contribution of circadian biology. In healthy populations and among those with heart disease, SCD is more likely to occur in the morning after waking, whereas bradyarrhythmias and paroxysmal atrial fibrillation are much more common at night.…”

“… 7 These circadian rhythms have provided therapeutic targets to reduce SCD, such as targeted use of β-blockers at night, 8 and recent interest in the antiarrhythmic properties of melatonin. 9 Given the paucity of evidence regarding the influence of circadian rhythms on arrhythmias in the population receiving hemodialysis, Soomro et al 6 aim to provide this while disentangling complex relationships with the timing of dialysis treatments and the presence or absence of heart failure.…”