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

Obstructive Sleep Apnea Characterization: A Multimodal Cross-Recurrence-Based Approach for Investigating Atrial Fibrillation

Obstructive sleep apnea (OSA) is believed to contribute significantly to atrial fibrillation (AF) development in certain patients. Recent studies indicate a rising risk of AF with increasing OSA severity. However, the commonly used apnea-hypopnea index in clinical practice may not adequately account for the potential cardiovascular risks associated with OSA. 1) Objective: to propose and explore a novel method for assessing OSA severity considering potential connection to cardiac arrhythmias. 2) Method: the approach utilizes cross-recurrence features to characterize OSA and AF by considering the relationships among oxygen desaturation, pulse arrival time, and heart-beat intervals. Multinomial logistic regression models were trained to predict four levels of OSA severity and four groups related to heart rhythm issues. The rank biserial correlation coefficient, rrb, was used to estimate effect size for statistical analysis. The investigation was conducted using the MESA database, which includes polysomnography data from 2055 subjects. 3) Results: a derived cross-recurrence-based index showed a significant association with a higher OSA severity (p 0.01) and the presence of AF (p 0.01). Additionally, the proposed index had a significantly larger effect, rrb, than the conventional apnea-hypopnea index in differentiating increasingly severe heart rhythm issue groups: 0.14 0.06, 0.33 0.10, and 0.41 0.07. 4) Significance: the proposed method holds relevance as a supplementary diagnostic tool for assessing the authentic state of sleep apnea in clinical practice.

Nocturnal Cardiac Arrhythmias in Heart Failure With Obstructive and Central Sleep Apnea

BACKGROUND

Both OSA and central sleep apnea (CSA) may contribute to nocturnal cardiac arrhythmias (NCAs). Data are scarce regarding the prevalence of clinically important nocturnal atrial and ventricular arrythmias in patients with heart failure with reduced ejection fraction (HFrEF) and OSA or CSA.

RESEARCH QUESTION

In a cohort of patients with HFrEF, how does the prevalence of NCA compare among those with OSA, CSA, and those with no to mild sleep apnea? Is the severity of OSA or CSA associated with atrial and ventricular NCAs?

STUDY DESIGN AND METHODS

This cross-sectional analysis is an ancillary study of the Effect of Adaptive Servo Ventilation on Survival and Hospital Admissions in Heart Failure (ADVENT-HF) trial. We compared the prevalence of NCAs (excessive supraventricular ectopic activity [ESVEA], defined as premature atrial complexes ≥30/h or supraventricular tachycardia ≥ 20 beats); atrial fibrillation/flutter [AF]; and > 10 premature ventricular complexes [PVC/h]) on ECGs from polysomnograms of patients with HFrEF between those with OSA (apnea-hypopnea index [AHI ≥ 15 events/h]), those with CSA (AHI ≥ 15 events/h), and those with no to mild sleep apnea (AHI < 15 events/h [control]).

RESULTS

The prevalence of ESVEA was higher in patients with OSA (n = 430) and CSA (n = 150) compared with control participants (n = 76): 0%, 9%, and 12%, respectively. The prevalence of AF in the control, OSA, and CSA groups was 9%, 17%, and 27%; the prevalence of > 10 PVC/h was 45%, 59%, and 63%. In multivariable regression analyses, premature atrial complexes/h was associated with OSA severity (obstructive AHI: 22.4% increase per 10 events/h [95% CI, 5.2-42.3; P = .009), although neither obstructive nor central AHI was associated with AF or > 10 PVC/h.

INTERPRETATION

In patients with HFrEF, the prevalences of nocturnal ESVEA, AF, and PVC > 10/h were higher in those with OSA or CSA than in those without OSA or CSA, and OSA severity was related to the burden of nocturnal atrial ectopy. Severity of OSA or CSA was not significantly related to AF or > 10 PVC/h.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT01128816; URL: www.

CLINICALTRIALS

gov.

Sleep apnea and sudden death in the non-cardiac population: A systematic review

INTRODUCTION

Obstructive sleep apnea (OSA) is one of the main risk factors for cardiovascular diseases and is associated with both morbidity and mortality. OSA has also been linked to arrhythmias and sudden death.

OBJECTIVE

To assess whether OSA increases the risk of sudden death in the non-cardiac population.

METHODS

This is a systematic review of the literature. The descriptors "sudden death" and "sleep apnea" and "tachyarrhythmias" and "sleep apnea" were searched in the PubMed/Medline and SciELO databases.

RESULTS

Thirteen articles that addressed the relationship between OSA and the development of tachyarrhythmias and/or sudden death with prevalence data, electrocardiographic findings, and a relationship with other comorbidities were selected. The airway obstruction observed in OSA triggers several systemic repercussions, e.g., changes in intrathoracic pressure, intermittent hypoxia, activation of the sympathetic nervous system and chemoreceptors, and release of catecholamines. These mechanisms would be implicated in the appearance of arrhythmogenic factors, which could result in sudden death.

CONCLUSION

There was a cause-effect relationship between OSA and cardiac arrhythmias. In view of the pathophysiology of OSA and its arrhythmogenic role, studies have shown a higher risk of sudden death in individuals who previously had heart disease. On the other hand, there is little evidence about the occurrence of sudden death in individuals with OSA and no heart disease, and OSA is not a risk factor for sudden death in this population.

Cardiac autonomic dysfunction and structural remodeling: the potential mechanism to mediate the relationship between obstructive sleep apnea and cardiac arrhythmias

Background

Cardiac arrhythmias are very common in patients with obstructive sleep apnea (OSA), especially atrial fibrillation (AF) and nonsustained ventricular tachycardia (NVST). Cardiac autonomic dysfunction and structural remodeling caused by OSA provide the milieu for cardiac arrhythmia development. This study aimed to determine whether OSA is associated with various cardiac arrhythmias and investigate potential pathophysiologic pathways between them.

Methods

The analysis covered 600 patients with clinical suspicion of OSA hospitalized in Renmin Hospital of Wuhan University between January 2020 and May 2023. After undergoing sleep apnea monitor, all subjects received laboratory tests, Holter electrocardiography, and Echocardiography.

Results

Compared with those without OSA and adjusting for potential confounders, subjects with moderate OSA had three times the odds of AF (odds ratio [OR] 3.055; 95% confidence interval [CI], 1.002-9.316; p = 0.048). Subjects with severe OSA had three times the odds of AF (OR 3.881; 95% CI, 1.306-11.534; p = 0.015) and NSVT (OR 3.690; 95% CI, 0.809-16.036; p = 0.046). There were significant linear trends for the association between OSA severity with AF and NVST (p < 0.05). And this association was mediated by cardiac structural changes including left atrial diameter, left ventricular diastolic diameter, right atrial diameter and right ventricular diameter. In addition, the ratio of low-frequency and high-frequency individually mediated the association between severe OSA and NVST.

Conclusion

This study demonstrated that severe OSA was independently associated with AF and NSVT, and this association was mediated by autonomic nervous system changes and cardiac structural remodeling.

Obstructive Sleep Apnea and Stroke: Determining the Mechanisms Behind their Association and Treatment Options

Sleep-disordered breathing (SDB) can be a sequela of stroke caused by vascular injury to vital respiratory centers, cerebral edema, and increased intracranial pressure of space-occupying lesions. Likewise, obstructive sleep apnea (OSA) contributes to increased stroke risk through local mechanisms such as impaired ischemic cerebrovascular response and systemic effects such as promoting atherosclerosis, hypercoagulability, cardiac arrhythmias, vascular-endothelial dysfunction, and metabolic syndrome. The impact of OSA on stroke outcomes has been established, yet it receives less attention in national guidelines on stroke management than hyperglycemia and blood pressure dysregulation. Furthermore, whether untreated OSA worsens stroke outcomes is not well-described in the literature. This scoping review provides an updated investigation of the correlation between OSA and stroke, including inter-relational pathophysiology. This review also highlights the importance of OSA treatment and its role in stroke outcomes. Knowledge of pathophysiology, the inter-relationship between these common disorders, and the impact of OSA therapy on outcomes affect the clinical management of patients with acute ischemic stroke. In addition, understanding the relationship between stroke outcomes and pre-existing OSA will allow clinicians to predict outcomes while treating acute stroke.

Investigate the relationship between obstructive sleep apnea and cardiac arrhythmia after CABG surgery

BACKGROUND AND OBJECTIVE

Heart rhythm disorder is one of the most common problems after coronary artery bypass graft surgery. Various factors, such as the history of sleep apnoea before the operation, may aggravate the occurrence of this disorder. The present study was conducted to determine the relationship between sleep apnoea before surgery and heart rhythm disorder after surgery in patients undergoing coronary Artery Bypass Grafting in 2019.

METHODS

This analytical cross-sectional study was conducted on 192 patients who were selected by sequential sampling. The research tool included demographic information, a checklist of heart rhythm disorders, and the Berlin sleep apnoea questionnaire. Descriptive statistics and the Chi-square test, Fisher's exact test, Mann-Whitney's U-test, and logistic regression were used to analyze the data.

RESULTS

A total of 71.35% of the samples were male, and the mean age of the participants was 57.8 ± 7.5 years. Also, 46.0% of the samples had sleep pane and 21.35% had rhythm disorder. The most frequent heart rhythm disorder in patients with obstructive sleep apnoea was atrial fibrillation. There was a significant relationship between the occurrence of rhythm disorder and a history of smoking (P = 0.021), and the regression model showed that a history of smoking is the only variable related to the occurrence of rhythm disorder after coronary Artery Bypass Grafting (P = 0.005, CI 95%: 6.566-1.386, OR = 3.017).

CONCLUSIONS

The results showed that there is no statistically significant relationship between sleep apnea and rhythm disorder after coronary artery bypass surgery.

Obstructive sleep apnea severity and prevalent atrial fibrillation in a sleep clinic cohort with versus without excessive daytime sleepiness

BACKGROUND

Obstructive sleep apnea (OSA) is associated with atrial fibrillation (AF) in cardiac cohorts. Less is known regarding the magnitude of this association in a sleep clinic cohort with vs. without excessive daytime sleepiness (EDS).

OBJECTIVES

To explore the association of OSA severity with AF in a sleep clinic cohort stratified by EDS.

PATIENTS AND METHODS

All consecutive adults (n = 3814) admitted to the Skaraborg Hospital, Sweden between Jan 2005 and December 2011 were registered in a local database, and the follow-up ended in December 2018. OSA was defined as an apnea-hypopnea index (AHI) ≥5 events/h. Mild OSA was defined as AHI ≥5 & AHI<15 events/h; moderate OSA as AHI ≥15 & AHI<30 events/h; and severe OSA as AHI ≥30 events/h. EDS was defined as an Epworth Sleepiness Scale score ≥11. We conducted cross-sectional analyzes of the prevalent AF across the OSA severity categories and logistic regression analyzes stratified by EDS.

RESULTS

In all, 202 patients (5.3%) had AF at baseline, 1.6% in no-OSA, 3.9% in mild OSA, 5.2% in moderate OSA, and 7.6% in severe OSA, respectively (p < 0.001). The stratified analyzes revealed that patients with severe OSA without EDS had an increased risk for prevalent AF (OR 2.54, 95% CI 1.05-6.16; p = 0.039) independent of the confounding factors.

CONCLUSIONS

There was an independent dose-response relationship between OSA and prevalent AF among the non-sleepy phenotype in this sleep clinic cohort. Since adherence to OSA treatment is challenging in the absence of EDS, these patients may have increased risk for adverse cardiovascular outcomes.

Risk factors in developing retinal vein occlusion in subject with obstructive sleep apnea

BACKGROUND

Patients with obstructive sleep apnea (OSA) have a higher risk of developing vascular diseases. In this study, we evaluated the clinical profile of patients with OSA who develop retinal vein occlusion (RVO) compared with a population of OSA patients without RVO.

METHODS

We analyzed patients with OSA diagnosed with RVO (21 cases; mean of age 61 years. range 44-87 years. 67% men), belonging to a large cohort of people with long-term follow-up for RVO (up to 12 years). We compared them with 21 patients with OSA, without RVO, matched by age and gender, selected from the Sleep Unit Registry (control group).

RESULTS

There were no differences in the prevalence of arterial hypertension (AHT) or Diabetes mellitus (DM), but the RVO patients presented a higher diastolic blood pressure compared to controls (87.6±12.6 mmHg vs. 77.9±10.1 mmHg respectively). The polygraphic parameters were similar in both groups. The Apnea-Hypopnea Index (IHA) similar in both groups (30.4±20.9 RVO vs. 33.7±22.1 controls). In addition, RVO patients had a less favorable lipid profile, with higher total cholesterol (218±52 mg/dL vs. 179±41 mg/dL), higher LDL cholesterol (139±47 mg/dL vs. 107±32 mg/dL) and higher atherogenic indices: LDL/HDL (2.78±0.95 RVO vs. 2.03±0.67 controls) and total cholesterol/HDL (4.37±1.08 vs. 3.45±0.84). Among the cases, 81% had peripheral RVO (superior temporal branch in 20 out of 21 cases) and 19% had central RVO. A percentage of 62% of the cases received intravitreal antiangiogenic therapy and dexamethasone implants and 33% received argon laser photocoagulation.

CONCLUSIONS

Poor control of cardiovascular risk factors, particularly dyslipidemias, in patients with OSA may lead to the development of this ocular complication.

Association of obstructive sleep apnea with cardiometabolic diseases and cardiovascular mortality

BACKGROUND

Obstructive sleep apnea (OSA) is one of the leading respiratory disorders, increasing the risk of cardiometabolic diseases. In the study, we investigated the association between OSA and the risk of cardiometabolic diseases and all-cause and cardiovascular mortality in adults.

METHODS

Participants were enrolled in the National Health and Nutrition Examination Survey. The baseline covariates were compared between participants with and without OSA status. Multivariable logistic regression was performed to explore the association between OSA and cardiometabolic diseases, while Cox proportional regression was performed for all-cause and cardiovascular mortality.

RESULTS

OSA status was positively associated with higher risks of cardiometabolic diseases, including hypertension (odds ratio [OR] 1.28, 95% confidence interval [CI] 1.14-1.45; p < 0.001), diabetes (OR 1.46, 95% CI 1.22-1.76; p < 0.001), and cardiovascular diseases (OR 1.29, 95% CI 1.08-1.54; p = 0.006) after adjusting for numerous covariates. However, no associations of OSA with all-cause or cardiovascular mortality were observed.

CONCLUSION

OSA was associated with a higher risk of hypertension, diabetes, and cardiovascular diseases, but had no significant association with all-cause or cardiovascular mortality in adults.

Obstructive Sleep Apnoea and Cardiac Arrhythmias (OSCA) trial: a nested cohort study using injectable loop recorders and Holter monitoring in patients with obstructive sleep apnoea

INTRODUCTION

Obstructive sleep apnoea (OSA) is associated with increased cardiovascular mortality despite continuous positive airways pressure (CPAP) therapy. This excess risk may be related to increased arrhythmia risk, especially atrial fibrillation (AF). The true incidence of arrhythmia in patients with OSA is unknown. Implantable loop recorders (ILR) are powerful tools for detecting arrhythmias long-term. Cardiac autonomic function may be important in arrhythmogenesis in these patients but needs further study. We aim to identify the true incidence of arrhythmias (especially AF) using ILRs, assess cardiac autonomic function using Holter monitors in patients with OSA and explore cardiovascular outcomes.

METHODS AND ANALYSIS

A two-centre (University Hospital Coventry and St. Cross Hospital, Rugby) nested cohort study using Reveal LINQ (Medtronic, UK) ILR to identify precise arrhythmia (atrial/ventricular) incidence in patients with moderate-severe OSA. 200 patients will be randomised 1:1 to standard care alone or standard care+ILR (+Holter monitor at baseline and 12 months). The primary objective is to compare arrhythmia detection over 3 years between the two groups. Cardiac autonomic function will be assessed in the ILR-arm at baseline and 12 months post CPAP. Secondary objectives will explore the mechanisms linking OSA and arrhythmia using cardiac autonomic function parameters based on Holter recordings and circulating biomarkers (high sensitivity Troponin-T, N-terminal pro B-type natriuretic peptide, matrix metalloproteinase-9, fibroblast growth factor 23, high sensitivity C-reactive protein, interleukin-6 and tumour necrosis factor-α) before and after CPAP initiation in the ILR-arm.

ETHICS AND DISSEMINATION

This study has been approved by the Health Research Authority after examination by the Solihull Research and Ethics Committee. The main ethical considerations was the minimally invasive nature of ILR insertion outside of usual care. Patient advisory groups were consulted with a positive outcome for this type of research. We plan on publishing papers in peer-reviewed journals based on the primary objective and any interesting findings from secondary objectives. We will endeavour to publish all relevant data.

TRIAL REGISTRATION NUMBER

NCT03866148.

Prevalence of silent atrial fibrillation and cardiovascular disease in patients with obstructive sleep apnea

OBJECTIVE

Patients with silent and undiagnosed atrial fibrillation (AF) have increased risk of ischemic stroke. Patients with obstructive sleep apnea (OSA) have an increased risk of both AF and ischemic stroke. Our aim was to investigate the prevalence of silent AF and associated risk factors in patients investigated for OSA or with known OSA.

METHODS

This prospective observational study was performed in two sites; one outpatient sleep-clinic at Zealand University Hospital and one private Ear-Nose- and Throat clinic. Patients were investigated with a type-3 portable sleep-monitoring device, while heart rhythm was home-monitored for 7 days with an event-triggered loop recorder. Patients were stratified in groups of mild, moderate and severe OSA based on Apnea-Hypopnea-Index (AHI).

RESULTS

In a cohort of 303 patients, 238 (78.5%) were diagnosed with moderate/or severe OSA and 65 (21.5%) with no/mild OSA who constituted the control group. In 238 patients with moderate and severe OSA, AF was detected in 21 patients (8.8%) vs. 1 patient (1.5%,[p=0.045]) with mild OSA. Candidates for anticoagulation therapy were referred for further cardiovascular treatment. The majority of patients had known hypertension (n = 200,66%) and dyslipidemia (n = 235,[77.6%]) In patients with moderate/or severe OSA (AHI≥15), hypertension was more dysregulated (p=0.005) and more patients suffered from unknown prediabetes (n = 36, 3.1% vs. 14.3%[p<0.001]).

CONCLUSION

Undiagnosed AF and undertreated cardiovascular modifiable risk factors are common in a cohort of patients with OSA. With this study we propose that long-period home-monitoring in these patients is useful for identifying candidates for preventive anticoagulation, cardiovascular treatment and possibly prevent future ischemic stroke.

A systematic review on the association of sleep-disordered breathing with cardiovascular pathology in adults

Sleep-disordered breathing (SDB) is characterized by repeated breathing pauses during sleep. The prevalence of SDB varies widely between studies. Some longitudinal studies have found an association of SDB with incident or recurrent cardiovascular events. We sought to systematically describe the current data on the correlation between SDB and cardiovascular pathology. Studies were included if they were original observational population-based studies in adults with clearly diagnosed SDB. The primary outcomes include all types of cardiovascular pathology. We carried out pooled analyses using a random effects model. Our systematic review was performed according to the PRISMA and MOOSE guidelines for systematic reviews and was registered with PROSPERO. In total, 2652 articles were detected in the databases, of which 76 articles were chosen for full-text review. Fourteen studies were focused on samples of an unselected population, and 8 studies were focused on a group of persons at risk for SDB. In 5 studies, the incidence of cardiovascular pathology in the population with SDB was examined. In total, 49 studies described SDB in patients with cardiovascular pathology. We found an association between SDB and prevalent /incident cardiovascular disease (pooled OR 1.76; 95% CI 1.38–2.26), and pooled HR (95% CI 1.78; 95% CI 1.34–2.45). Notably, in patients with existing SDB, the risk of new adverse cardiovascular events was high. However, the relationship between cardiovascular disease and SDB is likely to be bidirectional. Thus, more large-scale studies are needed to better understand this association and to decide whether screening for possible SDB in cardiovascular patients is reasonable and clinically significant.

Sleep-Disordered Breathing and Cardiac Arrhythmias in Adults: Mechanistic Insights and Clinical Implications: A Scientific Statement From the American Heart Association

Sleep-disordered breathing (SDB), characterized by specific underlying physiological mechanisms, comprises obstructive and central pathophysiology, affects nearly 1 billion individuals worldwide, and is associated with excessive cardiopulmonary morbidity. Strong evidence implicates SDB in cardiac arrhythmogenesis. Immediate consequences of SDB include autonomic nervous system fluctuations, recurrent hypoxia, alterations in carbon dioxide/acid-base status, disrupted sleep architecture, and accompanying increases in negative intrathoracic pressures directly affecting cardiac function. Day-night patterning and circadian biology of SDB-induced pathophysiological sequelae collectively influence the structural and electrophysiological cardiac substrate, thereby creating an ideal milieu for arrhythmogenic propensity. Cohort studies support strong associations of SDB and cardiac arrhythmia, with evidence that discrete respiratory events trigger atrial and ventricular arrhythmic events. Observational studies suggest that SDB treatment reduces atrial fibrillation recurrence after rhythm control interventions. However, high-level evidence from clinical trials that supports a role for SDB intervention on rhythm control is not available. The goals of this scientific statement are to increase knowledge and awareness of the existing science relating SDB to cardiac arrhythmias (atrial fibrillation, ventricular tachyarrhythmias, sudden cardiac death, and bradyarrhythmias), synthesizing data relevant for clinical practice and identifying current knowledge gaps, presenting best practice consensus statements, and prioritizing future scientific directions. Key opportunities identified that are specific to cardiac arrhythmia include optimizing SDB screening, characterizing SDB predictive metrics and underlying pathophysiology, elucidating sex-specific and background-related influences in SDB, assessing the role of mobile health innovations, and prioritizing the conduct of rigorous and adequately powered clinical trials.

Ventricular Arrhythmias in Patients with Implanted Cardiac Devices at High Risk of Obstructive Sleep Apnea

Background and Objectives: Patients with pre-existing cardiac disease have a higher prevalence of Obstructive Sleep Apnea (OSA). OSA has been associated with an increased risk of supraventricular and ventricular arrhythmia. We screened subjects with implanted pacemakers and automated implantable cardioverter defibrillators (AICD) for OSA with the Berlin Questionnaire and compared the incidence of ventricular arrhythmias and automated implantable cardioverter defibrillator (AICD) firing between high and low OSA risk groups. Materials and Methods: We contacted 648 consecutive patients from our arrhythmia clinic to participate in the study and performed final analyses on 171 subjects who consented and had follow-up data. Data were abstracted from the electronic health record for the incidence of non-sustained ventricular tachycardia (NSVT), ventricular tachycardia (VT), ventricular fibrillation (VF) and AICD firing and then compared between those at high versus low risk of OSA using the Berlin Questionnaire and multivariate negative binomial regression. Results: The average follow-up period was 24.2 ± 4.4 months. After adjusting for age, gender and history of heart failure, those subjects at high risk of OSA had a higher burden of NSVT vs. those with a low risk of OSA (33.4 ± 96.2 vs. 5.82 ± 17.1 episodes, p = 0.003). A predetermined subgroup analysis of AICD recipients also demonstrated a significantly higher burden of NSVT in the high vs. low OSA risk groups (66.2 ± 128.6 vs. 18.9 ± 36.7 episodes, p = 0.033). There were significant differences in the rates of VT, VF or AICD shock burden between the high and low OSA risk groups and in the AICD subgroup analysis. Conclusions: There was increased ventricular ectopy among pacemaker and AICD recipients at high risk of OSA, but the prevalence of VT, VF or AICD shocks was similar to those with low risk of OSA.

Less Well-Known Consequences of the Long-Term Use of Opioid Analgesics: A Comprehensive Literature Review

BACKGROUND

The adverse effects of short-term opioid analgesics are well known and acknowledged; however, the spectrum of the sequelae of long-term use seems less clear. Some effects may remain undetected but still have the potential to cause harm and reduce patients' quality of life.

OBJECTIVE

To review the literature on the adverse effects of long-term opioid therapy.

METHODS

We performed a quasi-systematic search, analyzing articles published in the MEDLINE database between January 2000 and March 2021 that identified adverse effects of opioids used for chronic pain treatment.

RESULTS

Growing evidence indicates that there are multiple serious adverse effects of opioid treatment. Long-term opioid use may have significant effects on the endocrine, immune, cardiovascular, respiratory, gastrointestinal, and neural systems. Studies show that long-term opioid treatment increases the risk of fractures, infections, cardiovascular complications, sleep-disordered breathing, bowel dysfunction, overdose, and mortality. Opioids may potentially affect cancer development. Most consequences of the long-term use of opioids have been identified in studies of patients with non-malignant pain.

CONCLUSION

Studies indicate that long-term use of opioids increases the risk of drug-related events in a significant number of patients. Clinicians should be aware of these complications associated with prescribing opioids, discuss them with patients, prevent complications, if possible, and diagnose them early and manage adequately. More human studies are needed to assess the risk, including trials with individual opioids, because they have different adverse effect profiles.

Obstructive Sleep Apnea and Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia, increasing with age and comorbidities. Obstructive sleep apnea (OSA) is a chronic sleep disorder more common in older men. It has been shown that OSA is linked to AF. Nonetheless, the prevalence of OSA in patients with AF remains unknown because OSA is significantly underdiagnosed. This review, including 54,271 patients, carried out a meta-analysis to investigate the association between OSA and AF. We also performed a meta-regression to explore cofactors influencing this correlation. A strong link was found between these two disorders. The incidence of AF is 88% higher in patients with OSA. Age and hypertension independently strengthened this association, indicating that OSA treatment could help reduce AF recurrence. Further research is needed to confirm these findings. Atrial Fibrillation (AF) is the most common arrhythmia, increasing with age and comorbidities. Obstructive sleep apnea (OSA) is a regulatory respiratory disorder of partial or complete collapse of the upper airways during sleep leading to recurrent pauses in breathing. OSA is more common in older men. Evidence exists that OSA is linked to AF. Nonetheless, the prevalence of OSA in patients with AF remains unknown because OSA is underdiagnosed. In order to investigate the incidence of AF in OSA patients, we carried out a meta-analysis including 20 scientific studies with a total of 54,271 subjects. AF was present in 4801 patients of whom 2203 (45.9%) had OSA and 2598 (54.1%) did not. Of a total of 21,074 patients with OSA, 2203 (10.5%) had AF and 18,871 (89.5%) did not. The incidence of AF was 88% higher in patients with OSA. We performed a meta-regression to explore interacting factors potentially influencing the occurrence of AF in OSA. Older age and hypertension independently strengthened this association. The clinical significance of our results is that patients with OSA should be referred early to the cardiologist. Further research is needed for the definition of the mechanisms of association between AF and OSA.

Obstructive sleep apnea and stroke: The mechanisms, the randomized trials, and the road ahead

When considered separately from cardiovascular disease, stroke is the third leading cause of death in the U.S. and is the leading cause of long-term disability in adults. New approaches that can be offered to the majority of ischemic stroke patients, can be continued throughout post-stroke care, can limit stroke severity, and can complement or even enhance rehabilitation, would transform ischemic stroke recovery. The treatment of obstructive sleep apnea (OSA) in patients with acute ischemic stroke may represent one such approach. This manuscript reviews the epidemiologic studies of the bidirectional association between OSA and stroke, and the mechanisms and molecular signatures of OSA leading to transient ischemic attack and stroke as well as the randomized controlled trials and observational cohort studies examining continuous positive airway treatment efficacy on the impact of stroke outcomes. Finally, the insights these studies provide on future research are also discussed.

Sleep-Disordered Breathing and Cardiovascular Disease in Children and Adolescents: A Scientific Statement From the American Heart Association

Obstructive sleep apnea (OSA) is a known risk factor for cardiovascular disease in adults. It is associated with incident systemic hypertension, arrhythmia, stroke, coronary artery disease, and heart failure. OSA is common in children and adolescents, but there has been less focus on OSA as a primary risk factor for cardiovascular disease in children and adolescents. This scientific statement summarizes what is known regarding the impact of sleep‐disordered breathing and, in particular, OSA on the cardiovascular health of children and adolescents. This statement highlights what is known regarding the impact of OSA on the risk for hypertension, arrhythmia, abnormal ventricular morphology, impaired ventricular contractility, and elevated right heart pressure among children and adolescents. This scientific statement also summarizes current best practices for the diagnosis and evaluation of cardiovascular disease–related complications of OSA in children and adolescents with sleep apnea and highlights potential future research in the area of sleep‐disordered breathing and cardiovascular health during childhood and adolescence.

Ventrikuläre Arrhythmien bei obstruktiver und zentraler Schlafapnoe

Hintergrund

Ventrikuläre Arrhythmien treten mit einer hohen Prävalenz auf und sind mit einer hohen Morbidität und Mortalität assoziiert. Sowohl die obstruktive (OSA) als auch die zentrale (ZSA) Schlafapnoe können auf Grund ihrer Pathophysiologie zu vermehrten ventrikulären Arrhythmien beitragen.

Ziel

Dieser Artikel soll die komplexen Zusammenhänge und Erkenntnisse jüngster Forschungen bezüglich schlafbezogenen Atmungsstörungen (SBAS) und ventrikulärer Arrhythmien und deren Therapiemöglichkeiten beleuchten.

Material und Methoden

Es erfolgte eine Literaturrecherche basierend auf prospektiven, retrospektiven, klinischen und experimentellen Studien sowie Reviews, Metaanalysen und aktuellen Leitlinien, die seit 2014 in der Medline-Datenbank gelistet wurden.

Ergebnisse

Es besteht ein bidirektionaler Zusammenhang zwischen der SBAS und ventrikulären Arrhythmien. Intermittierende Hypoxie, oxidativer Stress, wiederkehrende Arousals, intrathorakale Druckschwankungen und kardiales Remodeling tragen im Rahmen der SBAS zu einer erhöhten ventrikulären Arrhythmieneigung bei. Der Schweregrad der OSA, gemessen mittels Apnoe-Hypopnoe-Index, ist mit der Prävalenz ventrikulärer Arrhythmien assoziiert. Ähnliche Ergebnisse liegen für Patienten mit ZSA und Herzinsuffizienz vor. Studien zu ventrikulären Arrhythmien bei ZSA-Patienten ohne Herzinsuffizienz fehlen. Eine Positivdrucktherapie (PAP) bei OSA- oder ZSA-Patienten führte in verschiedenen Studien zu einer reduzierten Anzahl an ventrikulären Arrhythmien. Dieser Zusammenhang konnte jedoch nicht in allen Studien bestätigt werden. Ventrikuläre Arrhythmien treten bei der OSA gehäuft nachts auf, bei der ZSA gleichmäßig über den Tag verteilt.

Diskussion

Bisherige Studien weisen einen Zusammenhang zwischen der OSA bzw. der ZSA und ventrikulären Arrhythmien trotz unterschiedlicher Pathophysiologie nach. Hinsichtlich des Effektes der PAP auf ventrikuläre Arrhythmien bei Patienten mit OSA und ZSA sind weitere Studien erforderlich.

Obstructive Sleep Apnea as a Predictor of Arrhythmias in 24-h ECG Holter Monitoring

A relationship between obstructive sleep apnea (OSA) and abnormalities in 24-h electrocardiogram (ECG) Holter monitoring has not been sufficiently documented. The aim of this study was to analyze the relation between the occurrence and the severity of OSA and the parameters of ECG Holter monitoring in a group of patients with diagnosed OSA. Ninety-four patients with clinical suspicion of OSA were qualified for the study (mean age 53.7). All participants underwent a medical history, laboratory tests, 24-h ECG Holter monitoring, and single-night video-polysomnography (vPSG) using the American Academy of Sleep Medicine recommendations. A group of patients with diagnosed OSA was characterized by more frequent occurrence of supraventricular tachycardia (SVT) and ventricular arrhythmias (VPC). A statistically significant positive correlation was shown between the apnea-hypopnea index (AHI) and average heart rate, supraventricular arrhythmias (SVPC) pairs, SVT, and pauses >2.5 s. In regression analysis, higher AHI constituted an independent predicator for the increased number of pauses >2.5 s, SVT, and SVPC pairs in 24-h ECG Holter monitoring. In summary, patients with OSA are characterized by the increased number of abnormalities in 24-h ECG Holter monitoring.

Relationship Between Obstructive Sleep Apnea and Late Gadolinium Enhancement and Their Effect on Cardiac Arrhythmias in Patients with Hypertrophic Obstructive Cardiomyopathy

PURPOSE

Obstructive sleep apnea (OSA) and myocardial fibrosis are associated with cardiac arrhythmia. The purpose of this study was to explore the relationship between OSA and myocardial fibrosis, as well as their impact on cardiac arrhythmia in hypertrophic obstructive cardiomyopathy (HOCM) patients.

METHODS

We prospectively studied 151 consecutive patients with a confirmed diagnosis of HOCM at the Fuwai Hospital between September 2017 and 2018. Polysomnography, Holter electrocardiography, and cardiac magnetic resonance imaging were performed on all patients. Myocardial fibrosis was reflected by late gadolinium enhancement (LGE), detected using cardiac magnetic resonance imaging.

RESULTS

Myocardial fibrosis, measured using LGE%, was found to increase with increasing OSA severity [6.8% (3.6-12.9%), 6.1% (3.4-10.0%), 9.6% (5.5-14.5%), and 15.5% (9.3-20.0%) for no-OSA, mild OSA, moderate OSA, and severe OSA, respectively; p=0.003]. LGE% correlated with the New York Heart Association functional classifications (p=0.018), septal thickness (p=0.026), and apnea-hypopnea index (AHI) (p<0.001). The prevalence of isolated premature ventricular contraction (PVC) (p=0.028), paired PVC (p=0.036), ventricular bigeminy (p=0.005)/trigeminy (p<0.001), non-sustained ventricular tachycardia (NSVT) (p=0.001), isolated premature atrial contraction (PAC) (p=0.032), and supraventricular tachycardia (p=0.029) was significantly higher in patients with OSA. Additionally, LGE% and AHI were independent risk factors for isolated PVC (OR: 1.04, p=0.001 and OR: 1.07, p=0.039, respectively), ventricular bigeminy (OR: 1.04, p=0.003 and OR: 1.26, p=0.002, respectively)/trigeminy (OR: 1.07, p=0.040 and OR: 1.06, p=0.001, respectively), and NSVT (OR: 1.17, p<0.001 and OR: 1.08, p<0.001, respectively) after adjustment for age, sex, and other parameters.

CONCLUSION

Both OSA and LGE% were associated with a greater likelihood and increased frequency of ventricular arrhythmias (including NSVT) in patients with HOCM. Thus, the severity of OSA was independently associated with more severe myocardial fibrosis in patients with HOCM.

Nocturnal Arrhythmias and Heart-Rate Swings in Patients With Obstructive Sleep Apnea Syndrome Treated With Beta Blockers

Background

The higher cardiovascular variability and the increased prevalence of arrhythmias in patients with obstructive sleep apneas may contribute to their higher rate of fatal events during sleep. In this regard, the use of beta blockers (BB) is debated because they may induce bradyarrhythmias and alter the pattern of heart rate changes induced by apneas. Thus, the aim of our study is to quantify peri‐apneic heart‐rate swings and prevalence of nocturnal bradyarrhythmias in BB‐treated and BB‐naïve patients with obstructive sleep apnea.

Methods and Results

Our real‐life, retrospective, cohort study analyzed data from patients with obstructive sleep apnea after a basal cardiorespiratory polysomnography. Among 228 eligible participants, we enrolled 78 BB‐treated and 88 BB‐naïve patients excluding those treated with antiarrhythmic drugs or pacemakers, or with uninterpretable ECG traces during polysomnography. In each patient, type and frequency of arrhythmias were identified and peri‐apneic changes of RR intervals were evaluated for each apnea. BB‐treated patients were older and with more comorbidities than BB‐naïve patients, but had similar obstructive sleep apnea severity, similar frequency of arrhythmic episodes, and similar prevalence of bradyarrhythmias. Apnea‐induced heart‐rate swings, unadjusted for age, showed lower RR interval changes in BB‐treated (133.5±63.8 ms) than BB‐naïve patients (171.3±87.7 ms, P=0.01), lower RR interval increases during apneas (58.5±28.5 versus 74.6±40.2 ms, P=0.01), and lower RR interval decreases after apneas (75.0±42.4 versus 96.7±55.5 ms, P<0.05).

Conclusions

BB appear to be safe in patients with obstructive sleep apnea because they are not associated with worse episodes of nocturnal bradyarrhythmias and even seem protective in terms of apnea‐induced changes of heart rate.

Correlation between apnea-hypopnea index and Tp-Te interval, Tp-Te/QT, and Tp-Te/QTc ratios in obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder associated with important cardiovascular complications including ventricular arrhythmias. Tp‐Te interval, Tp‐Te/QT, and Tp‐Te/QTc ratios are repolarization indices representing ventricular arrhythmogenic potential. These parameters are associated with ventricular arrhythmias and sudden cardiac death. The aim of this study was to investigate the correlation between apnea–hypopnea index and Tp‐Te, Tp‐Te/QT, and Tp‐Te/QTc in OSA.

Methods

We screened a total of 280 patients who underwent overnight polysomnography (PSG) between the years 2012–2017 at our institution. Patients were assigned into four groups based on severity of apnea–hypopnea index: 70 with apnea–hypopnea index (AHI) <5 (control group), 71 with 5 ≤ AHI < 15, 63 with 15 ≤ AHI < 30, and 76 with AHI ≥ 30. Tp‐Te, Tp‐Te/QT, and Tp‐Te/QTc were measured.

Results

Compared to control group, repolarization parameters were significantly prolonged in other groups (Tp‐Te interval: 68.3 ± 6.8, 71.8 ± 6.3, 79.1 ± 5.5, and 85.1 ± 6.4 ms, p < .001; Tp‐Te/QT ratio: 167.5 ± 12.7, 181.7 ± 13.0, 202.2 ± 10.0 and 219.4 ± 13.5, p < .001; Tp‐Te/QTc ratio: 151.1 ± 16.6, 167.6 ± 16.6, 193.7 ± 14.4, and 225.5 ± 17.0, p < .001). There was a significant trend toward higher Tp‐Te, Tp‐Te/QT, and Tp‐Te/QTc across higher AHI categories. In a univariate regression analysis, body mass index, smoking status, Tp‐Te, and Tp‐Te/QTc were significantly associated with the severity of AHI in OSA. Tp‐Te (OR 1.629, 95% CI 1.393–1.906, p < .001), Tp‐Te/QTc (OR 1,333 95% CI 1.247–1.424, p < .001), and smoking status (OR 5.771, 95% CI 1.025–32.479, p = .047) were found to be significant independent predictors of severity of AHI in a multivariate analysis, after adjusting for other risk parameters.

Conclusions

Our study showed that Tp‐Te, Tp‐Te/QT, and Tp‐Te/QTc were prolonged in patients with OSA. There was significant correlation between apnea–hypopnea index and these parameters.

Environmental Factors as Modulators of the Relationship between Obstructive Sleep Apnea and Lesions in the Circulatory System

Obstructive sleep apnea (OSA) is a growing social problem, particularly in well-developed countries. It has been demonstrated that obstructive sleep apnea is a significant risk factor for cardiovascular diseases, including arterial hypertension, ischemic heart disease, heart failure, rhythm/conduction disturbances, as well as cerebral stroke. The pathophysiology of these diseases is complex and multifactorial. We present the current state of research on behavioral and environmental factors that influence the relationship between OSA and cardiovascular changes. We discuss the relationship between obesity, alcohol, sedatives, environmental tobacco smoke, allergic diseases and environmental pollution on the one hand and OSA on the other. In this context, the environment should be considered as an important modulator of the relationship between OSA and cardiovascular diseases.

Comparing treatment effects of a convenient vibratory positional device to CPAP in positional OSA: a crossover randomised controlled trial

OBJECTIVES

Up to 77% of patients with obstructive sleep apnoea (OSA) have positional OSA (POSA) but traditional positional therapy (PT) methods have failed as they were poorly tolerated. New convenient vibratory PT devices have been invented but while recent studies suggest high treatment efficacy and adherence, there are no published data comparing these devices directly with continuous positive airway pressure (CPAP). Our objective is to evaluate if a convenient vibratory PT device is non-inferior to CPAP in POSA treatment.

METHODS

In this crossover randomised controlled trial, we enrolled patients with POSA with significant daytime sleepiness (Epworth Sleepiness Scale (ESS)≥10). POSA diagnosis was based on: (1) total Apnoea/Hypopnoea Index (AHI)>10/hour and non-supine AHI<10/hour (2) supine AHI≥2 × non-supine AHI. Patients used their initial allocated devices (PT or CPAP) for 8 weeks before crossing to the alternative intervention after a 1 week washout. The primary aim is to measure changes in ESS between the two treatments. Secondary outcomes include sleep study parameters and patient treatment preference (ClinicalTrials.gov: NCT03125512).

RESULTS

40 patients completed the trial between April 2017 and December 2018. Difference in ESS after 8 weeks of device use (PT minus CPAP) was 2.0 (95% CI 0.68 to 3.32), exceeding our predetermined non-inferiority margin of 1.5. AHI on CPAP was lower than with PT (4.0±3.2 vs 13.0±13.8 events/hour, respectively, p=0.001), although both were lower than at baseline. Time spent supine was significantly lower with PT than CPAP (p<0.001). 60% of patients preferred CPAP, 20% preferred PT, while 20% preferred neither device.

CONCLUSIONS

The non-inferiority ESS endpoint for PT compared with CPAP was not met and the results were inconclusive. Future trials with larger sample sizes or in less symptomatic patients are warranted to provide further insight into the role of these new vibratory PT devices.

Obstructive Sleep Apnea as a Predictor of Abnormal Heart Rate Turbulence

Obstructive sleep apnea (OSA) causes dysfunction of the autonomic nervous system, but the exact mechanism has not been fully understood. The aim of this study was to analyse the relationship between the incidence and severity of OSA and heart rate turbulence (HRT). Seventy one patients with clinical suspicion of OSA were qualified to participate in the study. All participants took part in a survey and were subjected to laboratory tests, 24-hour electrocardiogram (ECG) Holter monitoring with HRT analysis and polysomnography. The group with OSA manifested significantly higher turbulence onset (TO) and lower turbulence slope (TS) as compared to the group without OSA. Older age, diabetes, hypertension and higher apnea/hypopnea index (AHI) were found to be independent risk factors for increased TO, whereas older age, higher body mass index (BMI), higher blood glucose levels, hypertension and higher AHI were independent risk factors for TS reduction. The AHI ≥65 criterion indicates abnormal HRT in patients with OSA with 94.9% sensitivity and 50.0% specificity, which gives a prediction accuracy of 85.7%. In summary, OSA should be considered as a predictor of abnormal HRT.

Arrhythmogenic mechanisms of obstructive sleep apnea in heart failure patients

Heart failure (HF) affects 23 million people worldwide and results in 300000 annual deaths. It is associated with many comorbidities, such as obstructive sleep apnea (OSA), and risk factors for both conditions overlap. Eleven percent of HF patients have OSA and 7.7% of OSA patients have left ventricular ejection fraction <50% with arrhythmias being a significant comorbidity in HF and OSA patients. Forty percent of HF patients develop atrial fibrillation (AF) and 30%-50% of deaths from cardiac causes in HF patients are from sudden cardiac death. OSA is prevalent in 32%-49% of patients with AF and there is a dose-dependent relationship between OSA severity and resistance to anti-arrhythmic therapies. HF and OSA lead to various downstream arrhythmogenic mechanisms, including metabolic derangement, remodeling, inflammation, and autonomic imbalance. (1) Metabolic derangement and production of reactive oxidative species increase late Na+ currents, decrease outward K+ currents and downregulate connexin-43 and cell-cell coupling. (2) remodeling also features downregulated K+ currents in addition to decreased Na+/K+ ATPase currents, altered Ca2+ homeostasis, and increased density of If current. (3) Chronic inflammation leads to downregulation of both Nav1.5 channels and K+ channels, altered Ca2+ homeostasis and reduced cellular coupling from alterations of connexin expression. (4) Autonomic imbalance causes arrhythmias by evoking triggered activity through increased Ca2+ transients and reduction of excitation wavefront wavelength. Thus, consideration of these multiple pathophysiological pathways (1-4) will enable the development of novel therapeutic strategies that can be targeted against arrhythmias in the context of complex disease, such as the comorbidities of HF and OSA.

Coexistence of obstructive sleep apnea and telomerase activity, concentration of selected adipose tissue hormones and vascular endothelial function in patients with arterial hypertension

AIM

The aim of the present study was to determine the effect of obstructive sleep apnea (OSA) with hypertension on telomerase activity, visfatin and adipsine concentration in the blood and vascular endothelial function assessed by ultrasound measured flow-mediated dilatation of the brachial artery (FMD).

MATERIAL AND METHODS

The study involved a group of 106 people (average age: 54.79 years). The determination of telomerase activity and blood visfatin and adipsine concentrations, brachial artery ultrasound examination with endothelium-dependent dilatation evaluation (FMD) and polysomnography were carried out.

RESULTS

Patients with hypertension without OSA were characterized by significantly greater FMD in comparison to patients with arterial hypertension and OSA (8.13 ± 5.12 %vs. 6.82 ± 5.36%; p < 0.05). Negative linear relationship between apnea-hypopnea index (AHI) and FMD (r = -0.22, p < 0.05) has been demonstrated. Negative linear relationship between adipsine concentration in the blood and length of REM (Rapid Eye Movement) sleep (r = -0.21, p < 0.05) was found. Positive linear relationship between the concentration of visfatin in the blood and the length of REM sleep (r = 0.22, p < 0.05) was also observed. Higher body mass index, higher total cholesterol, triglyceride and glucose levels have been shown to be independent predictors of higher AHI values, while greater telomerase activity, greater FMD and use of angiotensin converting enzyme inhibitors are independent predicators for lower AHI values.

CONCLUSION

Higher values of AHI index in polysomnography in hypertensive patients can be related to lower telomerase activity in the blood and impaired function of vascular endothelial function assessed using ultrasound.

Ventricular Arrhythmias in Patients with Obstructive Sleep Apnea

Obstructive Sleep Apnea (OSA) is a prevalent condition thought to increase in the future. Being mostly undiagnosed, the most serious complications are cardiovascular diseases, among which are arrhythmias. Controversy remains as to whether OSA is a primary etiologic factor for ventricular arrhythmias, because of the high incidence of cardiovascular comorbidities in OSA patients. Howev-er, there is mostly a strong evidence of a relation between OSA and ventricular arrhythmias. A few mechanisms have been proposed to be responsible for this association and some electrocardiographic changes have also been demonstrated to be more frequent in OSA patients. Treatment of OSA with Continuous Positive Airway Pressure (CPAP) has the potential to reduce arrhythmias and confer a mortality benefit.

Varying Hypopnea Definitions Affect Obstructive Sleep Apnea Severity Classification and Association With Cardiovascular Disease

STUDY OBJECTIVES

To compare clinical features and cardiovascular risks in patients with obstructive sleep apnea (OSA) based on ≥ 3% desaturation or arousal, and ≥ 4% desaturation hypopnea criteria.

METHODS

This is a cross-sectional analysis of 1,400 veterans who underwent polysomnography for suspected sleep-disordered breathing. Hypopneas were scored using ≥ 4% desaturation criteria per the American Academy of Sleep Medicine (AASM) 2007 guidelines, then re-scored using ≥ 3% desaturation or arousal criteria per AASM 2012 guidelines. The effect on OSA disease categorization by these two different definitions were compared and correlated with symptoms and cardiovascular associations using unadjusted and adjusted logistic regression.

RESULTS

The application of the ≥ 3% desaturation or arousal definition of hypopnea captured an additional 175 OSA diagnoses (12.5%). This newly diagnosed OSA group (OSA_new) was symptomatic with daytime sleepiness similarly to those in whom OSA had been diagnosed based on ≥ 4% desaturation criteria (OSA_4%). The OSA_new group was more obese and more likely to be male than those without OSA based on either criterion (No-OSA). However, the OSA_new group was younger, less obese, more likely female, and had a lesser smoking history compared to the OSA_4% group. Those with any severity of OSA_4% had an increased adjusted odds ratio for arrhythmias (odds ratio = 1.95 [95% confidence interval 1.37-2.78], P = .0155). The more inclusive hypopnea definition (ie, ≥ 3% desaturation or arousal) resulted in recategorization of OSA diagnosis and severity, and attenuated the increased odds ratio for arrhythmias observed in mild and moderate OSA_4%. However, severe OSA based on ≥ 3% desaturation or arousals (OSA3%/Ar) remained a significant risk factor for arrhythmias. OSA based on any definition was not associated with ischemic heart disease or heart failure.

CONCLUSIONS

The most current AASM criteria for hypopnea identify a unique group of patients who are sleepy, but who are not at increased risk for cardiovascular disease. Though the different hypopnea definitions result in recategorization of OSA severity, severe disease whether defined by ≥ 3% desaturation/arousals or ≥ 4% desaturation remains predictive of cardiac arrhythmias.

COMMENTARY

A commentary on this article appears in this issue on page 1971.

Sleep Disorders and Atrial Fibrillation: Current Situation and Future Directions

Atrial fibrillation (AF) is a growing health problem worldwide. In recent years, there has been a rising interest in the relationship between sleep disorders and AF. Several studies have reported higher prevalence and incidence rates of AF in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). However, some believe that OSAHS is not a risk factor for AF; but AF, by itself, is regarded as one of the possible triggers for OSAHS. In this study, the related literature investigating the association between OSAHS and AF was reviewed, and then the possible mechanisms of this interplay were discussed. To conclude, recommendations for further research in this field were presented to researchers and some points were highlighted for physicians.

Obstructive sleep apnea as a predictor of reduced heart rate variability

PURPOSE

This study aimed to analyze the relationship between the occurrence of obstructive sleep apnea (OSA) and heart rate variability (HRV) in a group of patients with clinical suggestion of OSA.

METHODS

104 patients with clinical suspicion of OSA were qualified to participate in the study (age: 53.15 ± 13.43 years). All participants took part in a survey and were subjected to laboratory tests, 24-hour ECG Holter monitoring, and polysomnography. The participants were divided into groups depending on the criterion of the presence of OSA.

RESULTS

The analysis of time HRV demonstrated lower parameters of SDNN for the entire recording and a 15-minute fragment of daily activity, as well as a lower pNN50 for the entire recording in those patients with diagnosed OSA. A statistically significant difference was observed for the spectral analysis of the LF/HF which was higher in the participants with OSA during the 15-minute fragment of N3 sleep. A negative correlation was observed between AHI and the following parameters: SDSD from the entire Holter recording (r = -0.21, p < 0.05) and from the 15-minute fragment of daily activity (r = -0.19, p < 0.05), mRR from the fragment of N3 sleep (r = -0.19, p < 0.05) and VLF from the entire Holter recording (r = -0.26, p < 0.05). A statistically significant positive correlation between AHI and LF/HF in 15-minute fragments of N3 sleep was found (r = 0.26, p < 0.05).

CONCLUSIONS

The study group of patients with OSA is characterized by reduced HRV. The higher AHI constitutes an independent predictor of reduced HRV, both in the sympathetic and parasympathetic components, and the sympathetic-parasympathetic balance.

Sudden Unexplained Nocturnal Death Syndrome: Epidemiological and Morphological Characteristics in Thai Autopsy Cases

With limited knowledge on epidemiological and morphological characteristics of sudden unexplained nocturnal death syndrome (SUNDS), this study was aimed to identify such data in Thai SUNDS autopsy cases. All the cases were men and nondrug abusers aged 20-49 years old. Most cases were originated in the Northeastern region of Thailand. Half of them were found dead from midnight to 6 a.m., with a peak time at 2 a.m. The death rate was relatively higher in May and June. Most SUNDS cases were blue-collar workers (93.2%) and nonsmokers (60%), with a normal BMI (72.1%). Approximately one-fifth of the cases had detectable blood alcohol concentrations. Symptoms before death were respiratory difficulty, seizures, and urinary incontinence. Their mean heart weight was 329.8 ± 35.1 g. Their lungs (88.6%) had some degree of congestion. Acute pancreatitis was not found in these SUNDS cases, and approximately half (40.9%) of the cases had their gastric content <100 mL.

Obstructive Sleep Apnea as a Risk Factor for Atrial Fibrillation: A Meta-Analysis

Objectives

To conducted a meta-analysis assessing the relationship between Obstructive Sleep Apnea (OSA) and the risk of Atrial Fibrillation (AF)

Methods

We searched PUBMED, Medline, and Cochrane Library using the keywords “atrial fibrillation”, “obstructive sleep apnea” and “sleep disordered breathing (SDB)”. All subjects included had established diagnosis of OSA/SDB. We then compared the occurrence of AF versus no AF. Analysis done with Comprehensive Meta-Analysis package V3 (Biostat, USA).

Results

A total of 579 results were generated. Duplicates were removed and 372 records were excluded based on irrelevant abstracts, titles, study design not consistent with the stated outcome, or full-text unavailable. Twelve studies meeting the inclusion criteria were reviewed in full-text; 2 of these articles were eventually removed due to unconfirmed OSA diagnostic modality, and one was also removed based on a control group inconsistent with the other studies. Therefore, a total of 9 studies were included (n=19,837). Sample sizes ranged from n=160 patients to n=6841 patients. The risk of AF was found to be higher among OSA/SDB versus control group (OR; 2.120, C.I: 1.845–2.436, Z; 10.598 p: <0.001). The heterogeneity observed for the pooled analysis was Q-value; 22.487 df (Q); 8 P-value; 0.004, I-squared; 64.424 Tau2; 0.098, suggesting appropriate study selection and moderate heterogeneity.

Conclusion

OSA/SDB is strongly associated with AFib confirming the notion that OSA/SDB populations are high risk for development of AF. Prospective studies are needed to ascertain the effect of the treatment of OSA/SDB for the prevention of AF, a growing health burden with serious consequences.

Prevalence and Predictors of Arrhythmia in Patients with Obstructive Sleep Apnea

Objectives

To assess the prevalence and types of arrhythmias in Saudi OSA patients and to identify predictors of arrhythmia in this group of patients.

Methods

This case-control study included all patients who underwent level I attended overnight polysomnography between 2009 and 2012. Electrocardiographic data collected during sleep studies of patients with and without OSA were manually reviewed.

Results

The study comprised 498 patients (394 OSA patients and 104 non-OSA patients (controls). The prevalence of arrhythmia in OSA patients was higher than that in the controls (26.9% vs. 11.5%; p=0.001). Comparing OSA patients and controls showed: premature atrial contraction (10.2%vs.2.9%;p=0.019), premature ventricular contraction (PVC) (19.3%vs.9.6%;p=0.02), non-isolated PVC (bi/tri/qua) 10.8%vs.2.3%;p=0.04) and atrial fibrillation (1.6%vs.0%;p=0.001). Multiple logistic regression analysis revealed that, patients with OSA had twice the odds of having any cardiac arrhythmia (OR 1.91; CI 95% 1.27-3.11; p <0.05).

Conclusions

Patients with OSA had a higher prevalence of arrhythmia compared to controls, and OSA is a predictor of arrhythmia during sleep.

Ambulatory clinical parameters and sleep respiratory events in a group of obese children unselected for respiratory problems

BACKGROUND

Obstructive sleep apnea in children is frequently due to tonsil and adenoid hypertrophy. This study aimed to investigate the relationship between ambulatory clinical parameters and sleep respiratory events in obese children.

METHODS

We carried out a prospective respiratory sleep study between 2013 and 2015. Nails obstruction, tonsils enlargement and palate position were subjectively measured. Italian attention deficit hyperactivity disorder (ADHD) rating scale for parents was also performed. The polygraph study was performed using a portable ambulatory device.

RESULTS

Forty-four obese children were consecutively recruited into this study. Mild sleep respiratory disturbance was showed in 31.8 % of patients; 18.2% previously had an adeno (tonsillectomy). In 50% of these obese children, both apnea-hypopnea index and oxygen desaturation index showed polygraph abnormal results. ADHD rating scale for parents scores were positive in 9.1% of patients.

CONCLUSIONS

We found a high rate of mild sleep respiratory disturbance and ADHD-like symptoms referred by parents. The respiratory disturbance was not totally cured by surgery. Finally, otorhinolaryngology variables were not able to explain mild sleep respiratory disturbance.

Potentially high-risk cardiac arrhythmias with focal to bilateral tonic-clonic seizures and generalized tonic-clonic seizures are associated with the duration of periictal hypoxemia

OBJECTIVE

To investigate potentially high-risk cardiac arrhythmias (PHAs) following focal to bilateral tonic-clonic seizures (FBTCSs) and generalized tonic-clonic seizures (GTCSs) and to study the association of PHAs with seizure characteristics and the severity of associated ictal respiratory dysfunction.

METHODS

Electrocardiographic (EKG) and pulse oximetry (SpO₂ ) data were recorded concurrently with video-electroencephalographic telemetry in the epilepsy monitoring unit (EMU). One minute of preictal EKG, the ictal EKG, and 2 min of ictal/postictal data were reviewed for each seizure. Nonsustained ventricular tachycardia, bradyarrhythmia, and/or sinus pauses were considered as PHAs. FBTCSs/GTCSs with PHAs were compared to those that had only ictal sinus tachycardia.

RESULTS

Data from 69 patients with 182 FBTCSs/GTCSs with usable SpO₂ and EKG recordings were available. There were 10 FBTCSs/GTCSs in 10 patients with a PHA. The presence of PHAs was not associated with seizure duration or SpO₂ nadir. FBTCSs/GTCSs with a PHA were significantly associated with the duration of oxygen desaturation < 90% when compared with FBTCSs/GTCSs with only sinus tachycardia (Mann-Whitney, p = 0.042). Desaturation duration of <100 s was not significantly associated with occurrence of PHAs (p = 0.110) when compared with seizures that had only sinus tachycardia. The odds ratio for occurrence of PHA was 7.86 for desaturation durations ≥ 125 s versus desaturations < 125 s (p = 0.005). The odds ratio increased to 13.09 for desaturation durations ≥ 150 s (p < 0.001). Preictal and ictal/postictal arrhythmias occurred with focal seizures that did not progress to FBTCSs. Four patients with focal seizures had ictal/postictal PHAs without preictal PHAs. Two of these patients had evidence for prior cardiac disturbance.

SIGNIFICANCE

PHAs following a single FBTCS/GTCS in the EMU are significantly associated with the duration of ictal/postictal hypoxemia. It is possible that FBTCS/GTCS-associated hypoxemia may trigger fatal cardiac arrhythmias in a subset of susceptible patients dying of sudden unexpected death in epilepsy.

Correlation Analysis between Obstructive Sleep Apnea Syndrome (OSAS) and Heart Rate Variability

BACKGROUND

Heart rate variability (HRV) represents the sympathetic nervous system activity induced by apnea or hypopnea events among OSAS patients. However, few studies have been conducted to clarify the association between HRV parameters and polysomnography (PSG) diagnostic indices. In our study, we postulate that the prevalence of cardiac arrhythmias is associated with OSAS, and HRV parameters may be an effective method for OSAS screening.

METHODS

Overall, 168 participants had been collected from 2011 to 2016 in the Second Affiliated Hospital of Soochow University. By apnea-hypopnea index (AHI), patients were separated into three subsets: AHI < 5 as control group, 5≤AHI<30 as mild-moderate OSAS group and AHI≥30as severe OSAS group. HRV and PSG parameters were collected based on electrocardiography and polysomnography system. Correlation analyses between standard deviation of R-R intervals (SDNN), SDNN index, RMSSD, PNN50, low frequency (LF), high frequency (HF) and LF/HF ratio and the AHI, ODI and MI were performed by Spearman's correlation analysis.

RESULTS

Compared with control group (64.5%) or mild-moderate OSAS group (67.3%), the prevalence of arrhythmias was considerably greater in severe OSAS group (P<0.05). Moreover, we demonstrated that LF/HF was greater in two OSAS groups than the normal group.

CONCLUSION

Correlation analyses revealed a significant and positive relation between the LF/HF and AHI, ODI and MI in OSAS patients. Severe OSAS could be attributed to enhanced danger of incident arrhythmia. LF/HF ratio as a relevant feature may be an effective parameter for detecting OSAS.

Pathway for the Management of Sleep Apnea in the Cardiac Patient

Sleep-disordered breathing is a highly prevalent medical condition, which if undiagnosed leads to increased morbidity and mortality, particularly related to increased incidence of cardiovascular events. It is therefore imperative that we identify patient population at high risk for sleep apnea and refer them to the appropriate therapy as early as possible. Up-to-date there is no management guideline specifically geared towards cardiac patients. Thus, we propose a (SAP) Sleep Apnea Pathway to correctly identify and triage these patients to the appropriate therapy.

Sleep-Disordered Breathing and Arrhythmia in Heart Failure Patients

Heart failure (HF) treatment remains complex and challenging, with current recommendations aiming at consideration and treatment of comorbidities in patients with HF. Sleep-disordered breathing (SDB) and arrhythmia come into play, as both are associated with quality of life deterioration, and morbidity and mortality increase in patients with HF. Interactions of these diseases are versatile and may appear intransparent in daily practice. Nevertheless, because of their importance for patients' condition and prognosis, SDB and arrhythmia individually, but also through interaction on one another, necessitate attention, following the fact that treatment is requested and desired considering latest research findings and outcomes.