Longitudinal effect of nocturnal R-R intervals changes on cardiovascular outcome in a community-based cohort

Abstract

RationaleSleep-disordered breathing (SDB) is strongly linked to adverse cardiovascular outcomes (cardiovascular diseases (CVD)). Whether heart rate changes measured by nocturnal R-R interval (RRI) dips (RRI dip index (RRDI)) adversely affect the CVD outcomes is unknown.ObjectivesTo test whether nocturnal RRDI predicts CVD incidence and mortality in the Wisconsin Sleep Cohort study (WSCS), independent of the known effects of SDB on beat-to-beat variability.MethodsThe study analysed electrocardiograph obtained from polysomnography study to assess the nocturnal total RRDI (the number of RRI dips divided by the total recording time) and sleep RRDI (the number of RRI dips divided by total sleep time). A composite CVD risk as a function of total and sleep RRDI was estimated by Cox proportional hazards in the WSCS.ResultsThe study sample consisted of 569 participants from the WSCS with no prior CVD at baseline were followed up for up to 15 years. Nocturnal total RRDI (10-unit change) was associated with composite CVD event(s) (HR, 1.24 per 10-unit increment in RRDI (95% CI 1.10 to 1.39), p<0.001). After adjusting for demographic factors (age 58±8 years old; 53% male; and body mass index 31±7 kg/m2), and apnoea–hypopnoea index (AHI 4%), individuals with highest total nocturnal RRDI category (≥28 vs<15 dips/hour) had a significant HR for increased incidence of CVD and mortality of 7.4(95% CI 1.97 to 27.7), p=0.003). Sleep RRDI was significantly associated with new-onset CVD event(s) (HR, 1.21 per 10-unit increment in RRDI (95% CI 1.09 to 1.35), p<0.001) which remained significant after adjusting for demographic factors, AHI 4%, hypoxemia and other comorbidities.ConclusionIncreased nocturnal RRDI predicts cardiovascular mortality and morbidity, independent of the known effects of SDB on beat-to-beat variability. The frequency of RRDI is higher in men than in women, and is significantly associated with new-onset CVD event(s) in men but not in women.

Can Pulse Rate Responses Be a Metric of Cardiovascular Outcome in Patients with Obstructive Sleep Apnea?

“…They found that the upper quartile of pulse rate changes was associated with increased cardiovascular morbidity and mortality risk. The main findings of the study corroborate our previous work on the WSCS (Wisconsin Sleep Cohort Study) using actual electrocardiogram-derived signal (R-R interval tracing) ( 2 ). However, the WSCS secondary analysis excluded individuals on chronotropic medications (e.g., a β-blocker or calcium channel blocker), which dampen the autonomic response to respiratory events and affect the sensitivity of the heart rate metric ( 3 ).…”

Characteristics of the Dynamic Electrocardiogram in the Elderly with Nonvalvular Atrial Fibrillation Combined with Long R-R Intervals

“…The mechanism may be that the autonomic nerve regulates the heart, and the vagal nerve tension increases; when the human body is in sleep, the vagal tone is increased, which leads to decreased concealed conduction and refractory periods in the atrioventricular junction. This then drives the propagation of the f-wave to the ventricle, thereby reducing the atrioventricular nodal hidden conduction, further increasing the rate of atrioventricular impulse transmission down to the ventricle and leading to higher fastest and slowest ventricular rates compared with the nonsleeping states [ 10 ]. Additionally, we observed a paroxysmal increase in the long R-R interval when the patients were not in sleep, while some patients were found to have long R-R intervals both in sleep and nonsleep periods (Supplementary Figures 3 and 4 ).…”

The Different Facets of Heart Rate Variability in Obstructive Sleep Apnea

“…Bradicich et al (238) and Wang et al (24) demonstrated associations between HRV and characteristics of polysomnographic parameters, however, they did not attempt to use HRV as a CVD risk predictor in this part of the SHHS dataset. Sankari et al (239) suggested beat-to-beat intervals index (RRDI) during sleep is closely correlated to new-diagnosis CVD (hazard ratio of 1.21 per 10-unit increment in RRDI) in OSA patients from the Wisconsin Sleep Cohort, but they did not utilize other linear and non-linear HRV measures to show the further relationship between CV risk and OSA.…”