Nocturnal Arrhythmias across a spectrum of obstructive and central sleep-disordered breathing in older men: outcomes of sleep disorders in older men (MrOS sleep) study

The Association between Nocturnal Cardiac Arrhythmias and Sleep-Disordered Breathing: The DREAM Study

STUDY OBJECTIVES

To determine whether sleep-disordered breathing (SDB) is associated with cardiac arrhythmia in a clinic-based population with multiple cardiovascular comorbidities and severe SDB.

METHODS

This was a cross-sectional analysis of 697 veterans who underwent polysomnography for suspected SDB. SDB was categorized according to the apnea-hypopnea index (AHI): none (AHI < 5), mild (5 ≥ AHI < 15), and moderate-severe (AHI ≥ 15). Nocturnal cardiac arrhythmias consisted of: (1) complex ventricular ectopy, (CVE: non-sustained ventricular tachycardia, bigeminy, trigeminy, or quadrigeminy), (2) combined supraventricular tachycardia, (CST: atrial fibrillation or supraventricular tachycardia), (3) intraventricular conduction delay (ICD), (4) tachyarrhythmias (ventricular and supraventricular), and (5) any cardiac arrhythmia. Unadjusted, adjusted logistic regression, and Cochran-Armitage testing examined the association between SDB and cardiac arrhythmias. Linear regression models explored the association between hypoxia, arousals, and cardiac arrhythmias.

RESULTS

Compared to those without SDB, patients with moderate-severe SDB had almost three-fold unadjusted odds of any cardiac arrhythmia (2.94; CI 95%, 2.01-4.30; p < 0.0001), two-fold odds of tachyarrhythmias (2.16; CI 95%,1.47-3.18; p = 0.0011), two-fold odds of CVE (2.01; 1.36-2.96; p = 0.003), and two-fold odds of ICD (2.50; 1.58-3.95; p = 0.001). A linear trend was identified between SDB severity and all cardiac arrhythmia subtypes (p value linear trend < 0.0001). After adjusting for age, BMI, gender, and cardiovascular diseases, moderate-severe SDB patients had twice the odds of having nocturnal cardiac arrhythmias (2.24; 1.48-3.39; p = 0.004). Frequency of obstructive respiratory events and hypoxia were strong predictors of arrhythmia risk.

CONCLUSIONS

SDB is independently associated with nocturnal cardiac arrhythmias. Increasing severity of SDB was associated with an increasing risk for any cardiac arrhythmia.

Atrial fibrillation in first generation Chinese migrants living in Europe: A proof of concept study

BACKGROUND

Despite the public health burden of atrial fibrillation (AF) and its complications in China, there is no literature on AF among Chinese living in Europe. The present study was performed to investigate the prevalence of and risk factors for AF in Chinese first generation migrants settled in Europe.

METHODS

A cross-sectional survey was performed in 2014 on Chinese first generation migrants aged 16 to 59years settled in Prato (Italy) adopting principles of community based participatory research. All participants underwent recording of 30s of a single-channel ECG and associations of AF with socio-demographic, anthropometric, clinical factors, and sleep history were examined using logistic regression.

RESULTS

Of the 1608 participants, 12 had AF (0.75%; 95% CI 0.33 to 1.17) - four men and eight women. All subjects with AF had a CHA2DS2VASc index≥1. Although no participant with AF had contraindications to oral anticoagulation, none was treated with oral anticoagulants. At multivariable adjusted logistic regression AF was associated with hypertension with an OR of 4.40 (95% CI 1.09-17.81; p=0.038).

CONCLUSIONS

Chinese are one of the fastest growing migrant populations in Europe and their health has become a key issue to host nations. The issue of AF is to be considered in future prevention programs for elusive ethnic minorities and adequately powered trials specifically designed to investigate AF prevalence and to test prevention approaches are now needed.

Atrial Fibrillation And Sleep Apnea: Considerations For A Dual Epidemic

Atrial fibrillation (AF) is the most common cardiac arrhythmia and shares many of the same risk factors as another common clinical condition, sleep apnea. The estimated prevalence of sleep apnea has increased over the past decade, and reflects a parallel increase in the most prominent risk factors of obesity and overweight. Both obstructive and central sleep apnea have been associated with AF in multiple studies, with the risk of AF increasing 2-4-fold compared to those without sleep breathing disorder. Continuous positive airway pressure (CPAP) has been shown to reduce the rate of AF recurrence following catheter ablation in patients with sleep apnea. However, the mechanisms by which sleep apnea precipitates AF or vice versa, remain unclear. In this Review, we examine the current date linking AF and sleep apnea, discuss the existing data supporting a mechanistic link between the two conditions, present the existing evidence for the effectiveness of CPAP in this growing population, and suggest approaches to screen AF patients for sleep breathing disorders.

Obstructive Sleep Apnea and Cognition in Parkinson's disease

OBJECTIVE

Obstructive sleep apnea (OSA) is very common in Parkinson's disease (PD). OSA is known to affect patients' cognition. The present study assessed whether PD patients with OSA (PD + OSA) score lower on cognitive measures than those without OSA (PD - OSA). In addition, this study evaluated whether treating the OSA with continuous positive airway pressure (CPAP) in PD + OSA patients results in an improved cognitive functioning.

METHODS

Eighty-six patients with PD underwent an overnight polysomnography screen for OSA and were administered the Mini-Mental Status Exam (MMSE) and the Montreal Cognitive Assessment (MoCA). This resulted in 38 patients with PD + OSA who were randomly assigned to receive either therapeutic CPAP for 6 weeks (n = 19) or placebo CPAP for three weeks followed by therapeutic CPAP for three weeks (n = 19). Intervention participants completed a neurocognitive battery at baseline and 3- and 6-week time-points.

RESULTS

Patients with PD + OSA scored significantly lower than PD - OSA on the MMSE and MoCA after controlling for age, education, and PD severity. OSA was a significant predictor of cognition (MMSE p <0.01; MoCA p = 0.028).There were no significant changes between groups in cognition when comparing three weeks of therapeutic CPAP with 3 weeks of placebo CPAP. Comparisons between pre-treatment and 3-week post-therapeutic CPAP for the entire sample also revealed no significant changes on overall neuropsychological (NP) scores.

CONCLUSIONS

Findings suggest that PD patients with OSA show worse cognitive functioning on cognitive screening measures than those without OSA. However, OSA treatment after three or six weeks of CPAP may not result in overall cognitive improvement in patients with PD.

Sleep disordered breathing and cardiovascular risk in older patients initiating dialysis in the United States: a retrospective observational study using medicare data

Background

Sleep disordered breathing (SDB) such as sleep apnea is associated with cardiovascular disease in the general population. However, little is known about the cardiovascular risks of SDB in patients with end-stage renal disease (ESRD).

Methods

We identified Medicare fee-for-service beneficiaries aged ≥67 years initiating dialysis between 2004 and 2009. Outcomes of interest included all-cause mortality, incident myocardial infarction, ischemic stroke, and atrial fibrillation. We compared patients with and without diagnosed SDB using Cox proportional hazards regression.

Results

Between 2004 and 2009, 184,217 older patients developed ESRD, of whom 15,121 (8.2 %) were previously diagnosed with SDB. Patients diagnosed with SDB were younger, more likely to be male and Caucasian, less Medicaid eligible, had more non-Nephrology clinic visits, higher body mass index, and more comorbidity. In analyses adjusting for demographics and BMI, diagnosed SDB was associated with higher risk of death and atrial fibrillation, but not associated with myocardial infarction or ischemic stroke risk. After further adjustment for all baseline characteristics, diagnosed SDB was associated with slightly lower risks of death (hazard ratio [HR]: 0.93, 95 % confidence interval [CI]: 0.91–0.96), myocardial infarction (HR: 0.92, CI: 0.87–0.98), and ischemic stroke (HR: 0.90, 95 % CI: 0.82–0.98), and not associated with atrial fibrillation (HR: 1.02, CI: 0.98–1.07).

Conclusions

In older patients initiating dialysis in the U.S., diagnosed SDB was weakly associated with lower risks of death and important cardiovascular outcomes, thus adding to the list of established risk factors that are paradoxically associated with cardiovascular outcomes in the ESRD population.

Osteoporosis in men: findings from the Osteoporotic Fractures in Men Study (MrOS)

The lifespan of men is increasing and this is associated with an increased prevalence of osteoporosis in men. Osteoporosis increases the risk of bone fracture. Fractures are associated with increased disability and mortality, and public health problems. We review here the study of osteoporosis in men as obtained from a longitudinal cohort of community-based older men, the Osteoporotic Fractures in Men Study (MrOS).

Exercise-induced ventricular arrhythmias: analysis of predictive factors in a population with sleep disorders

OBJECTIVE

To assess the prevalence of ventricular arrhythmias induced by exercise in a population with sleep disorders and to analyze the triggering factors.

METHODS

Patients were consecutively selected from the database of the Sleep Clinic of Universidade Federal de São Paulo. All subjects were submitted to basal polysomnography, blood sample collection, physical examination, 12-lead ECG, spirometry, cardiorespiratory exercise study on a treadmill, and echocardiogram. The Control Group was matched for age and gender.

RESULTS

A total of 312 patients were analyzed. Exercise-induced ventricular arrhythmia was observed in 7%. The aortic diameter was larger (3.44 ± 0.30, 3.16 ± 0.36, p = 0.04) and the minimal saturation was lower (92.75 ± 3.05, 95.50 ± 1.73, p=0.01) in the ventricular arrhythmia group when compared to controls, respectively. After correction of the aortic root to body surface, there was only a trend to a larger diameter being associated with the emergence of arrhythmia.

CONCLUSIONS

Exercise-induced ventricular arrhythmia was observed in 7% of sample and it was associated with lower oxygen saturation during exercise.

Relationship of Bisphosphonate Therapy and Atrial Fibrillation/Flutter: Outcomes of Sleep Disorders in Older Men (MrOS Sleep) Study

BACKGROUND

Prior studies suggested an association between bisphosphonates and atrial fibrillation/flutter (AF) in women. This relationship in men, including those with sleep-disordered breathing (SDB), remains unclear. This study evaluated the relationship between bisphosphonate use and prevalent (nocturnal) and incident (clinically relevant) AF in a population of community-dwelling older men.

METHODS

A total of 2,911 male participants (mean age, 76 years) of the prospective observational Osteoporotic Fractures in Men Study sleep cohort with overnight in-home polysomnography (PSG) constituted the analytic cohort. Nocturnal AF from ECGs during PSG and incident AF events were centrally adjudicated. The association of bisphosphonate use and AF was examined using multivariable-adjusted logistic regression for prevalent AF and Cox proportional hazards regression for incident AF.

RESULTS

A total of 123 (4.2%) men were current bisphosphonate users. Prevalent nocturnal AF was present in 138 participants (4.6%). After multivariable adjustment, there was a significant association between current bisphosphonate use and prevalent AF (OR, 2.33; 95% CI, 1.13-4.79). In the subset of men with moderate to severe SDB, this association was even more pronounced (OR, 3.22; 95% CI, 1.29-8.03). However, the multivariable-adjusted relationship between bisphosphonate use and incident AF did not reach statistical significance (adjusted hazard ratio, 1.53; 95% CI, 0.96-2.45).

CONCLUSIONS

These results support an association between bisphosphonate use and prevalent nocturnal AF in community-dwelling older men. The data further suggest that those with moderate to severe SDB may be a particularly vulnerable group susceptible to bisphosphonate-related AF. Similar associations were not seen for bisphosphonate use and clinically relevant incident AF.

Use of Ambulatory Blood Pressure Monitoring for the Screening of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a frequent and underdiagnosed disease in hypertensive individuals who experience cardiovascular events. The aim of this study was to define the best model that combined the ambulatory blood pressure (BP) monitoring (ABPM), anthropometric, sociodemographic, and biological variables to identify moderate to severe OSA. A total of 105 ABPM-confirmed hypertensive patients were evaluated using their clinical histories, blood analyses, ABPM, and home respiratory polygraphic results. A multivariate logistic regression analysis was performed to identify the significant variables. The best model included sex, presence of obesity (body mass index ≥30 kg/m(2) and abdominal obesity), mean daytime BP, mean nocturnal heart rate, and minimal diastolic nighttime BP to achieve an area under the curve of 0.804. Based on this model, a validated scoring system was developed to identify the patients with an apnea-hypopnea index ≥15. Therefore, in untreated hypertensive patients who snored, ABPM variables might be used to identify patients at risk for OSA.

Association of sleep characteristics with atrial fibrillation: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Population-based studies have linked measures of sleep disordered breathing to nocturnally occurring atrial fibrillation (AF) episodes. Whether measures of sleep disordered breathing and sleep quality are associated with prevalent AF has not been studied in an unselected population. We investigated the cross-sectional association with prevalent AF of objectively collected prespecified measures of overnight sleep breathing disturbances, sleep stage distributions, arousal and sleep duration.

METHODS

AF prevalence, defined by diagnosis codes, study electrocardiography and sleep study were examined among Multi-Ethnic Study of Atherosclerosis (MESA) participants who underwent polysomnography in the MESA Sleep Study (n=2048).

MEASUREMENTS AND MAIN RESULTS

Higher apnoea hypopnoea index (AHI) was associated with increased odds of AF, although the significance was attenuated after full adjustment for covariates including prevalent cardiovascular disease (OR: 1.22 (0.99 to 1.49) per SD (17/h), p=0.06). Analyses of sleep architecture measures and AF revealed significantly lower odds of AF associated with longer duration of slow wave sleep (OR: 0.66 (0.5 to 0.89) per SD (34 min), p=0.01) which persisted after additionally adjusting for AHI (OR: 0.68 (0.51 to 0.92), p=0.01). Higher sleep efficiency was significantly associated with lower likelihood of AF but the significance was lost when adjusted for AHI. No significant association was present between sleep duration and AF. In a model including AHI and arousal index, the association between AHI and AF was strengthened (AHI: OR 1.49 (1.15 to 1.91) per SD, p=0.002) and a significant inverse association between arousal index and AF was observed (OR 0.65 (0.50 to 0.86) per SD (12/h), p=0.005).

CONCLUSIONS

In a study of a large multiethnic population, AF was associated with AHI severity, and was more common in individuals with poor sleep quality as measured by reduced slow wave sleep time, a finding that was independent of AHI.

Sleep, death, and the heart

Obstructive and central sleep apnea have been associated with increased risk of adverse cardiovascular events and mortality. Sympathetic dysregulation occurring as a result of the respiratory disturbance is thought to play a role in this increased risk. Sleep apnea increases the risk of arrhythmias, myocardial ischemia/infarction, stroke, and heart failure, all of which may increase mortality risk. A higher incidence of nocturnal arrhythmias, cardiac ischemia, and sudden death has been noted in subjects with sleep-disordered breathing (SDB). In this review, the association between SDB and each of these conditions is discussed, as well as the potential mechanisms underlying these risks and the effects of treatment of SDB. Particular emphasis is placed on the relationship between SDB and nocturnal atrial and ventricular arrhythmias, myocardial ischemia/infarction and sudden death.

Association of Sleep Apnea and Snoring With Incident Atrial Fibrillation in the Multi-Ethnic Study of Atherosclerosis

The association between sleep apnea and atrial fibrillation (AF) has not been examined in a multiethnic adult population in prospective community-based studies. We prospectively (2000-2011) investigated the associations of physician-diagnosed sleep apnea (PDSA), which is considered more severe sleep apnea, and self-reported habitual snoring without PDSA (HS), a surrogate for mild sleep apnea, with incident AF in white, black, and Hispanic participants in the Multi-Ethnic Study of Atherosclerosis (MESA) who were free of clinical cardiovascular disease at baseline (2000-2002). Cox proportional hazards models were used to assess the associations, with adjustment for socioeconomic status, traditional vascular disease risk factors, race/ethnicity, body mass index, diabetes, chronic kidney disease, alcohol intake, and lipid-lowering therapy. Out of 4,395 respondents to a sleep questionnaire administered in MESA, 181 reported PDSA, 1,086 reported HS, and 3,128 reported neither HS nor PDSA (unaffected). Over an average 8.5-year follow-up period, 212 AF events were identified. As compared with unaffected participants, PDSA was associated with incident AF in the multivariable analysis, but HS was not (PDSA: hazard ratio = 1.76, 95% confidence interval: 1.03, 3.02; HS: hazard ratio = 1.02, 95% confidence interval: 0.72, 1.44). PDSA, a marker of more severe sleep apnea, was associated with higher risk of incident AF in this analysis of MESA data.

Automated detection of atrial fibrillation from the electrocardiogram channel of polysomnograms

PURPOSE

Accurate identification of atrial fibrillation episodes from polysomnograms is important for research purposes but requires manual review of a large number of long electrocardiographic tracings. As automated assessment of these tracings for atrial fibrillation may improve efficiency, this study aimed to evaluate this approach in polysomnogram-derived electrocardiographic data.

METHODS

A previously described algorithm to detect atrial fibrillation from single-lead electrocardiograms was applied to polysomnograms from a large epidemiologic study of obstructive sleep apnea in older men (Osteoporotic Fractures in Men [MrOS] Sleep Study). Atrial fibrillation status during each participant's PSG was determined by independent manual review. Models to predict atrial fibrillation status from a combination of algorithm output and clinical/polysomnographic characteristics were developed, and their accuracy was evaluated using standard statistical techniques.

RESULTS

Derivation and validation cohorts each consisted of 1395 individuals; 5 % of each group had atrial fibrillation. Model parameters were optimized for the derivation cohort using the Akaike information criterion. Application to the validation cohort of these optimized models revealed high sensitivity (85-90 %) and specificity (90-95 %) as well as good predictive ability, as assessed by the C statistic (>0.9) and generalized R (2) values (∼0.6). Addition of cardiovascular or polysomnogram data to the models did not improve their performance.

CONCLUSIONS

In a research setting, automated detection of atrial fibrillation from polysomnogram-derived electrocardiographic signals appears feasible and agrees well with manual identification. Future studies can evaluate the utility of this technique as applied to clinical polysomnograms and ambulatory electrocardiographic monitoring.

Obstructive Sleep Apnea and Atrial Fibrillation: Pathophysiology and Implications for Treatment

Obstructive sleep apnea (OSA) is increasingly recognized as an important risk factor for arrhythmogenesis. Epidemiological and clinical studies have suggested a strong association between OSA and atrial fibrillation (AF). With the increasing global epidemic of obesity, the incidence of OSA is also expected to rise. Various mechanisms mediated through adverse electrical and structural changes have been proposed to explain the increased risk of AF in patients with OSA. Multiple studies have also observed a greater risk of AF recurrence after cardioversion and catheter ablation (CA) in the patients with untreated OSA. The epidemiological and pathophysiological associations between OSA and AF have significant implications on the treatment outcomes of rhythm-control strategies for AF. Adequate screening and optimal management of OSA are of key importance to help improve the clinical outcomes following cardioversion and CA. In this review, we sought to describe the role of various mechanisms by which OSA mediates the pathogenesis of AF and contributes to adverse outcomes following CA.

Obstructive Sleep Apnoea and Atrial Fibrillation

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia and is associated with significant morbidity and mortality. Obstructive sleep apnoea (OSA) is common among patients with AF. Growing evidence suggests that OSA is associated with the initiation and maintenance of AF. This association is independent of obesity, body mass index and hypertension. OSA not only promotes initiation of AF but also has a significant negative impact on the treatment of AF. Patients with untreated OSA have a higher AF recurrence rate with drug therapy, electrical cardioversion and catheter ablation. Treatment with continuous positive airway pressure (CPAP) has been shown to improve AF control in patients with OSA. In this article, we will review and discuss the pathophysiological mechanisms of OSA that may predispose OSA patients to AF as well as the standard and emerging therapies for patients with both OSA and AF.

Sleep-Disordered Breathing and Cardiac Arrhythmias

Over the past few years sleep-disordered breathing has been identified as an important factor in arrhythmogenesis and a potential target of therapy to prevent cardiac arrhythmias in selected patients. In this review we highlight the role of obstructive sleep apnea and Cheyne-Stokes respiration in the pathophysiology of arrhythmias, address their clinical effect in supraventricular and ventricular tachyarrhythmias, and in conduction disturbances, and address the role of current treatment options for sleep-disordered breathing in the primary and secondary prevention of arrhythmic events.

[Association of sleep-disordered breathing and malignant arrhythmias in patients with ischemic and dilated cardiomyopathy]

Sleep-disordered breathing (SDB) has so far been a neglected comorbidity in patients with cardiac arrhythmias. Recently however, several studies have revealed a correlation between SDB and malignant ventricular arrhythmias. This review article is intended to provide the reader with an update on the pathophysiological association between SDB and ventricular arrhythmias, available clinical data, and therapeutic options.

Arrhythmia risk associated with sleep disordered breathing in chronic heart failure

The intersecting relationships of sleep disordered breathing (SDB), arrhythmogenic risk and chronic heart failure (HF) are complex and most likely multi-directional and synergistic. Autonomic dysfunction is a common pathophysiological feature of each of these entities. Intermittent hypoxia, hypercapnia, mechanical cardiac influences due to upper airway obstruction and rostral fluid shifts are SDB-specific mechanisms which may trigger, perpetuate and exacerbate HF and arrhythmogenesis. Specific pathophysiological mechanisms will vary according to the predominance of central as compared to obstructive sleep apnea. The risk of cardiac arrhythmias and HF attributable to SDB may be considerable given the high prevalence of SDB and its likely physiologic burden. The current review focuses on the data, which have accrued elucidating the specific contributory mechanisms of SDB in cardiac arrhythmias and HF, highlighting the clinical relevance and effects of standard SDB treatment on these outcomes, and describing the role of novel therapeutics.

Cardiac arrhythmias and sleep-disordered breathing in patients with heart failure

The relationship between heart failure (HF), sleep-disordered breathing and cardiac arrhythmias is complex and poorly understood. Whereas the frequency of predominantly obstructive sleep apnea in HF patients is low and similar or moderately higher to that observed in the general population, central sleep apnea (CSA) has been observed in approximately 50% of HF patients, depending on the methods used to detect CSA and patient selection. Despite this high prevalence, it is still unclear whether CSA is merely a marker or an independent risk factor for an adverse prognosis in HF patients and whether CSA is associated with an increased risk for supraventricular as well as ventricular arrhythmias in HF patients. The current review focuses on the relationship between CSA and atrial fibrillation as the most common atrial arrhythmia in HF patients, and on the relationship between CSA and ventricular tachycardia and ventricular fibrillation as the most frequent cause of sudden cardiac death in HF patients.

A systematic review of the association between obstructive sleep apnea and ventricular arrhythmias

INTRODUCTION

Obstructive sleep apnea (OSA) is an independent risk factor for sudden cardiac death. The aim of this review was to study the relationship between OSA and ventricular arrhythmias.

METHODS

PubMed, Medline, and Cochrane databases were searched with MESH headings to find studies linking OSA and ventricular arrhythmias including ventricular ectopy, ventricular tachycardia (VT), and ventricular fibrillation (VF). Studies were graded by a scoring system, and an attempt was made to pool data.

RESULTS

There were no matched cohort or case control studies to study the association between OSA and ventricular arrhythmias. Given data heterogeneity, pooling and meta-analysis of data were not possible. An attempt was made to judge the quality of evidence and present a systematic review. Patients with OSA were noted to have higher odds of ventricular ectopy, and were at a higher risk for ventricular arrhythmias. Associations included higher QTc dispersion and HR variability. We did not, however, find any clear evidence for a direct correlation between increased apnea hypopnea index and increased VT or VF.

CONCLUSIONS

Pooling and meta-analysis of studies linking OSA and ventricular arrhythmias were not possible due to heterogeneity of data. In a systemic review of studies, patients with OSA were noted to have higher odds of ventricular ectopy and arrhythmias. A single study showed that CPAP may help lower arrhythmogenicity; however, it was unclear if CPAP lowered the risk of VT. Further research should focus on studying the association of OSA and causes of sudden cardiac death, including ventricular arrhythmias.

Prevalence and correlates of obstructive sleep apnoea among patients with and without HIV infection

OBJECTIVES

In HIV-uninfected populations, obstructive sleep apnoea (OSA) is commonly associated with cardiovascular disease, metabolic syndrome, and cognitive impairment. These comorbidities are common in HIV-infected patients, but there are scarce data regarding OSA in HIV-infected patients. Therefore, we examined the prevalence and correlates of OSA in a cohort of HIV-infected and uninfected patients.

METHODS

An observational cohort study was carried out. Electronic medical record and self-report data were examined in patients enrolled in the Veterans Aging Cohort Study (VACS) between 2002 and 2008 and followed until 2010. The primary outcome was OSA diagnosis, determined using International Classification of Diseases, 9th edition (ICD-9) codes, in HIV-infected compared with uninfected individuals. We used regression analyses to determine the association between OSA diagnosis, symptoms and comorbidities in adjusted models.

RESULTS

Of 3683 HIV-infected and 3641 uninfected patients, 143 (3.9%) and 453 (12.4%) had a diagnosis of OSA (p<0.0001), respectively. HIV-infected patients were more likely to report symptoms associated with OSA such as tiredness and fatigue. Compared with uninfected patients with OSA, HIV-infected patients with OSA were younger, had lower body mass indexes (BMIs), and were less likely to have hypertension. In models adjusting for these traditional OSA risk factors, HIV infection was associated with markedly reduced odds of OSA diagnosis (odds ratio 0.48; 95% confidence interval 0.39-0.60).

CONCLUSIONS

HIV-infected patients are less likely to receive a diagnosis of OSA. Future studies are needed to determine whether the lower prevalence of OSA diagnoses in HIV-infected patients is attributable to decreased screening and detection or to a truly decreased likelihood of OSA in the setting of HIV infection.

Effects of aging on genioglossus motor units in humans

The genioglossus is a major upper airway dilator muscle thought to be important in obstructive sleep apnea pathogenesis. Aging is a risk factor for obstructive sleep apnea although the mechanisms are unclear and the effects of aging on motor unit remodeled in the genioglossus remains unknown. To assess possible changes associated with aging we compared quantitative parameters related to motor unit potential morphology derived from EMG signals in a sample of older (n = 11; >55 years) versus younger (n = 29; <55 years) adults. All data were recorded during quiet breathing with the subjects awake. Diagnostic sleep studies (Apnea Hypopnea Index) confirmed the presence or absence of obstructive sleep apnea. Genioglossus EMG signals were analyzed offline by automated software (DQEMG), which estimated a MUP template from each extracted motor unit potential train (MUPT) for both the selective concentric needle and concentric needle macro (CNMACRO) recorded EMG signals. 2074 MUPTs from 40 subjects (mean±95% CI; older AHI 19.6±9.9 events/hr versus younger AHI 30.1±6.1 events/hr) were extracted. MUPs detected in older adults were 32% longer in duration (14.7±0.5 ms versus 11.1±0.2 ms; P  =  0.05), with similar amplitudes (395.2±25.1 µV versus 394.6±13.7 µV). Amplitudes of CNMACRO MUPs detected in older adults were larger by 22% (62.7±6.5 µV versus 51.3±3.0 µV; P<0.05), with areas 24% larger (160.6±18.6 µV.ms versus 130.0±7.4 µV.ms; P<0.05) than those detected in younger adults. These results confirm that remodeled motor units are present in the genioglossus muscle of individuals above 55 years, which may have implications for OSA pathogenesis and aging related upper airway collapsibility.

Obstructive sleep apnea in older adults is a distinctly different physiological phenotype

STUDY OBJECTIVES

Current evidence suggests that the pathological mechanisms underlying obstructive sleep apnea (OSA) are altered with age. However, previous studies examining individual physiological traits known to contribute to OSA pathogenesis have been assessed in isolation, primarily in healthy individuals.

DESIGN

We assessed the four physiological traits responsible for OSA in a group of young and old patients with OSA.

SETTING

Sleep research laboratory.

PARTICIPANTS

Ten young (20-40 y) and old (60 y and older) patients with OSA matched by body mass index and sex.

MEASUREMENTS AND RESULTS

Pharyngeal anatomy/collapsibility, loop gain (LG), upper airway muscle responsiveness/gain (UAG) and the respiratory arousal threshold were determined using multiple 2- to 3-min decreases or drops in continuous positive airway pressure (CPAP). Passive pharyngeal anatomy/collapsibility was quantified as the ventilation at CPAP = 0 cmH2O immediately after the CPAP drop. LG was defined as the ratio of the ventilatory overshoot to the preceding reduction in ventilation. UAG was taken as the ratio of the increase in ventilation to the increase in ventilatory drive across the pressure drop. Arousal threshold was estimated as the ventilatory drive that caused arousal. Veupnea was quantified as the mean ventilation prior to the pressure drop. In comparison with younger patients with OSA, older patients had a more collapsible airway (ventilation at 0 cmH2O = 3.4 ± 0.9 versus 1.5 ± 0.7 L/min; P = 0.05) but lower Veupnea (8.2 ± 0.5 versus 6.1 ± 0.4 L/min; P < 0.01) and a lower LG (5.0 ± 0.7 versus 2.9 ± 0.5; P < 0.05). The remaining traits were similar between groups.

CONCLUSIONS

Our data suggest that airway anatomy/collapsibility plays a relatively greater pathogenic role in older adults, whereas a sensitive ventilatory control system is a more prominent trait in younger adults with obstructive sleep apnea.

CITATION

Edwards BA, Wellman A, Sands SA, Owens RL, Eckert DJ, White DP, Malhotra A. Obstructive sleep apnea in older adults is a distinctly different physiological phenotype.

Sleep-disordered breathing increases the risk of arrhythmias

Sleep-disordered breathing (SDB) has been consistently associated with increased risk for cardiovascular diseases, including arrhythmias. The purpose of this review is to elucidate the several pathophysiologic pathways such as repetitive hypoxia and reoxygenation, increased oxidative stress, inflammation and sympathetic activation that may underlie the increased incidence of arrhythmias in SDB patients. We discuss in particular the incidence of ventricular arrhythmias, atrial fibrillation and bradyarrhythmias in SDB patients. In addition, we discuss the electrocardiographic alteration such as ST-T changes during apneic events and QT dispersion induced by SDB that may trigger complex ventricular arrhythmias and sudden cardiac death. Finally, we consider also the therapeutic interventions such as continuous positive airways pressure therapy, a standard treatment for SDB, that may reduce the incidence and recurrence of supraventricular and ventricular arrhythmias in patients with SDB.

Periodic limb movements during sleep and cardiac arrhythmia in older men (MrOS sleep)

STUDY OBJECTIVES

To determine if periodic limb movements during sleep (PLMS) are associated with nocturnal cardiac arrhythmia.

METHODS

2,793 community-dwelling older men underwent polysomnography with measurement of limb movements and EKG. Logistic regression assessed association of periodic limb movement index and periodic limb movement arousal index with arrhythmia including atrial fibrillation and non-sustained ventricular tachycardia detected by polysomnography. Models were adjusted for age, race, cardiovascular risk factors, and clinic site. Secondary analyses were subset to men without calcium channel/β-adrenergic medication usage, and stratified by congestive heart failure or myocardial infarction history.

RESULTS

In the overall cohort, periodic limb movement index, and periodic limb movement arousal index were not associated with ventricular or atrial arrhythmia after considering potential confounders. In men not taking calcium channel/β-blocking medication, increased adjusted odds of non-sustained ventricular tachycardia were observed for periodic limb movement index (OR = 1.30 per SD increase; 95% CI 1.00, 1.68) and periodic limb movement arousal index (OR = 1.29 per SD increase; 95% CI 1.03, 1.62). In men with CHF or MI, there was a suggested association of atrial fibrillation with periodic limb movement index (OR = 1.29, 95% CI 0.96, 1.73 per SD increase; p = 0.09) or periodic limb movement arousal index (OR = 1.21, 95% CI 0.94, 1.57 per SD increase; p = 0.14), although results were not statistically significant.

CONCLUSIONS

There is not an association between PLMS and cardiac arrhythmia in all older men but in subsets of men, particularly those with structural heart disease and not on calcium channel or β-adrenergic medication, cardiac arrhythmia does associate with PLMS.

Unattended home-based polysomnography for sleep disordered breathing: current concepts and perspectives

Recently, portable sleep recording devices became an accepted alternative to polysomnography (PSG) for obstructive sleep apnea (OSA) diagnosis in patients with a high pre-test probability of moderate to severe OSA but home polysomnography (H-PSG) was not recommended because there were insufficient data. The present review has analysed six prospective randomized crossover studies comparing H-PSG to in-lab PSG. These studies convincingly showed that H-PSG allows complete sleep evaluation. The quality of patients' sleep tends to be better at home. H-PSG is accurate for OSA diagnosis and the failure rate is low despite the absence of supervision. In addition, it could offer a final and comprehensive diagnosis for many other sleep disorders. It is also likely that H-PSG can reduce PSG-related costs but complete cost-effectiveness analyses are not yet available. Recently, remotely attended H-PSG via telemonitoring has been tested and may reduce H-PSG failure rate. In conclusion, H-PSG can be used to rule-in and rule out OSA in suspected patients, even in the presence of co-morbidities and is an alternative when simplified sleep testing is negative. Future developments should target simplification of technical aspects of H-PSG, together with remote monitoring, in order to obtain good quality H-PSG performed in adequate conditions.

Association between obstructive sleep apnea and premature supraventricular contractions

OBJECTIVE

The exact association between obstructive sleep apnea (OSA) and premature supraventricular contractions (PSVCs) has not been established.

METHODS

We prospectively performed polysomnography together with 24-hour Holter electrocardiography in 431 patients who were clinically suspected of having OSA and examined the association between OSA severity and PSVCs during wakefulness and sleep. The patients were classified into 4 groups according to the apnea-hypopnea index (AHI) quartiles (Q1=patients with AHI<13.8, Q2=those with 13.8≤AHI<28.8, Q3=those with 28.8≤AHI<48.1, Q4=those with AHI≥48.1).

RESULTS

The number of PSVCs/hour during sleep differed significantly among the 4 groups, but the number of PSVCs/hour during wakefulness did not. The prevalence of PSVC≥5/hour during sleep was significantly higher in Q4 (21.0%) than the other 3 groups (Q1, 9.0%; Q2, 8.0%; Q3, 6.0%; all p<0.05 for Q4), but the prevalence of PSVC≥5/hour during wakefulness did not differ among the 4 groups. A multivariate logistic regression analysis showed that the highest AHI quartile was significantly associated with PSVC≥5/hour during sleep (odds ratio 3.04, 95% confidence interval 1.44-6.42, p=0.004).

CONCLUSIONS

Severe OSA can cause PSVCs during sleep, but its effect appears not to be strong. Further studies are needed to clarify the clinical significance of this small but significant increase in PSVCs during sleep in severe OSA patients.

Treatment of Cheyne-Stokes respiration reduces arrhythmic events in chronic heart failure

OBJECTIVE

This study aimed to investigate whether adequate treatment of Cheyne-Stokes respiration (CSR) reduces the risk of arrhythmic events in patients with chronic heart failure (CHF).

METHODS

A cohort of 403 registry patients with CHF (LVEF≤45%, NYHA-class≥2) and implanted cardioverter-defibrillator devices (ICD) was studied. They underwent overnight polygraphy, with 221 having mild or no CSR (apnea-hypopnea index [AHI]<15/h), and 182 having moderate to severe CSR (AHI>15/h). Latter ones were offered therapy with adaptive servoventilation (ASV), which 96 patients accepted and 86 rejected. During follow-up (21± 15 months) defibrillator therapies were recorded in addition to clinical and physiologic measures of heart failure severity.

RESULTS

Event-free survival from (a) appropriate cardioverter-defibrillator therapies and (b) appropriately monitored ventricular arrhythmias was shorter in the untreated CSR group compared to the treated CSR and the no CSR group. Stepwise Cox proportional hazard regression analysis showed untreated CSR (a: hazard ratio [HR] 1.99, 95% confidence interval [CI] 1.46-2.72, P < 0.001; b: HR 2.19, 95%CI 1.42-3.37, P < 0.001), but not treated CSR (a: HR 1.06, 95%CI 0.74-1.50; P = 0.77; b: HR 1.21, 95%CI 0.75-1.93, P = 0.43) was an independent risk factor. The treated CSR group showed improvements in cardiac function and respiratory stability compared to the untreated CSR group.

CONCLUSION

This study demonstrates a decrease of appropriate defibrillator therapies by ASV treated CSR in patients with CHF and ICD. A reduced exposure to hyperventilation, hypoxia, and improvement in indices of CHF severity and neurohumoral disarrangements are potential causative mechanisms.

Central sleep apnoea and inflammation are independently associated with arrhythmia in patients with heart failure

AIMS

We examined whether the severity of central sleep apnoea (CSA) and the level of C-reactive protein are associated with the prevalence and complexity of arrhythmias, and whether these factors contribute to increased risk of nocturnal sudden death.

METHODS AND RESULTS

We prospectively examined 178 patients (age 70 ± 1 years) who were admitted to our hospital due to worsening heart failure. We recorded a simultaneous overnight cardiorespiratory polygraph and Holter ECG. Obstructive sleep apnoea was excluded and patients were dichotomized based on the median value of the central apnoea index (CAI) of 7.5/h. The prevalence and complexity of arrhythmias were compared between daytime (06:00 h to 15:00 h) and night-time (21:00 h to 06:00 h). A multivariate logistic regression analysis revealed that the CAI was associated with prevalence of atrial fibrillation (AF) [odds ratio 1.03, 95% confidence interval (CI) 1.02-2.51)] and sinus pause during the night-time period (1.12, 95% CI 1.08-1.35). The CAI and C-reactive protein were independently associated with non-sustained ventricular tachycardia during both daytime (1.22, 95% CI 1.00-6.92; and 5.82, 2.58-56.1, respectively) and night-time periods (3.57, 95% CI 1.06-13.1; and 10.7, 3.30-44.4, respectively). During a mean follow-up period of 22 months, 30 (17%) patients had cardiovascular deaths and the CSA was an independent predictor (hazard ratio 1.29, 95% CI 1.16-2.32); only 5 (2.8%) of them died due to ventricular tachyarrhythmia, occurring during wakefulness.

CONCLUSIONS

We demonstrated that the severity of CSA and C-reactive protein levels are independently associated with the prevalence and complexity of arrhythmias. CSA was associated with increased mortality risk, but it was not related directly to nocturnal death due to ventricular tachyarrhythmia.

Usefulness of extended holter ECG monitoring for serious arrhythmia detection in patients with heart failure and sleep apnea

BACKGROUND

In patients with systolic heart failure (HF), coexisting sleep apnea may promote arrhythmia. Ambulatory Holter electrocardiogram (ECG) monitoring (AECG) is a method of arrhythmia and apnea evaluation. We hypothesized that 24-hour AECG in patients with HF who have a high risk of serious arrhythmia may be less accurate than AECG extended to 48 hours and that, moreover, arrhythmia may be related to apnea.

METHODS

Eighty-four recordings of 48-hour AECG in 84 patients with ischemic HF (mean ejection fraction 34 ± 7%) were analyzed. Day 1, Day 2 were checked for ventricular tachycardia (VT) and supraventricular tachycardia (SVT). Estimated apnea-hypopnea index (est.AHI) was calculated using Holter, monitoring where est.AHI >15 indicates apnea.

RESULTS

In 48-hour AECG, VT occurred in 34 patients (40.5%) whereas SVT in 17 patients (20.2%), and patients with est.AHI > 15 had higher VT occurrence. In two-sample one-sided test for proportions, 24-hour AECG from Day 1 showed a significantly lower percentage of patients with detected VT than 48-hour AECG-it was 23.8% (20 patients), meaning a significant underestimation with P = 0.0089. We assessed VT underestimation in the subgroups with regard to est.AHI, and found that it was present in Day 1 monitoring in the subgroups with est.AHI > 15. It was absent in the subgroups with est.AHI ≤ 15 and also in Day 2 monitoring.

CONCLUSIONS

In patients with systolic HF, 24-hour AECG may have insufficient sensitivity regarding serious arrhythmia occurrence. If significant apnea was detected in the first day, extending the monitoring may be recommended.

The Relationship between Obstructive Sleep Apnea and Atrial Fibrillation: A Complex Interplay

In recent years, growing evidence suggests an association between obstructive sleep apnea (OSA), a common sleep breathing disorder which is increasing in prevalence as the obesity epidemic surges, and atrial fibrillation (AF), the most common cardiac arrhythmia. AF is a costly public health problem increasing a patient's risk of stroke, heart failure, and all-cause mortality. It remains unclear whether the association is based on mutual risk factors, such as obesity and hypertension, or whether OSA is an independent risk factor and causative in nature. This paper explores the pathophysiology of OSA which may predispose to AF, clinical implications of stroke risk in this cohort who display overlapping disease processes, and targeted treatment strategies such as continuous positive airway pressure and AF ablation.

Impact of Obstructive Sleep Apnea on Outcomes of Catheter Ablation of Atrial Fibrillation

Obstructive sleep apnea (OSA) is a growing epidemic in the United States and significantly contributes to the increasing prevalence of atrial fibrillation (AF) in the U.S.

POPULATION

Although a strong correlation between OSA and AF has been demonstrated, a causal relationship between these two conditions has not been definitively established. Evidence of OSA is an important consideration of AF management and impacts the success rate of catheter ablation. The presence of OSA tends to predict a lower success rate and higher complication rate for catheter ablation of AF. However, recent studies evaluating OSA as an independent risk predictor of AF recurrence following an ablation procedure have yielded conflicting results. A greater understanding of these conditions would allow for a more specific therapy targeting the type of AF associated with OSA. The following review provides a brief summary of obstructive sleep apnea etiology, focuses on the relationship between OSA and AF, and discusses the impact of OSA on the outcomes of catheter ablation of AF.