Decreased right and left ventricular myocardial performance in obstructive sleep apnea

BACKGROUND: Obstructive sleep apnea (OSA) may predispose patients to congestive heart failure (CHF), suggesting a deleterious effect of OSA on myocardial contractility. METHODS: A cross-sectional study of 85 subjects with suspected OSA who had undergone their first overnight polysomnogram, accompanied by an echocardiographic study. Patients were divided according to the apnea-hypopnea index as follows: < 5 (control subjects); 5 to 14 (mild OSA); and >or= 15 (moderate-to-severe OSA). Right and left ventricular function was evaluated using the myocardial performance index (MPI) and other echocardiographic parameters. For the right ventricle analyses, we excluded patients with a Doppler pulmonary systolic pressure of >or= 45 mm Hg, while for the left ventricle we excluded patients with an ejection fraction of 相似文献   

Effects of obstructive sleep apnea severity on serum lipid levels in Greek children with snoring

Background

Although obstructive sleep apnea (OSA) is related to dyslipidemia in adults, limited data are available regarding its effects on serum lipids during childhood. Aim of this study was to assess the potential relationships between severity of OSA and cholesterol or triglyceride levels in a cohort of Greek children.

Methods

Data from children with snoring who underwent polysomnography and complete serum lipids measurements during a specified study period were analyzed retrospectively.

Results

Overall, obese children (n?=?261) had lower HDL cholesterol levels than non-obese subjects (n?=?113) (49.6?±?10.5 vs. 53.9?±?11.4 mg/dL; p?=?0.001) and higher triglyceride concentrations (69.8?±?32.2 vs. 63.2?±?27 mg/dL; p?=?0.041). Non-obese subjects with moderate-to-severe OSA did not differ in triglycerides, total, and LDL cholesterol concentrations but had lower HDL cholesterol, when compared to non-obese children with primary snoring/mild OSA (50.4?±?13.1 vs. 54.9?±?10.7 mg/dL; p?=?0.008). The risk for having low HDL cholesterol (??40 mg/dL) was threefold higher in non-obese subjects with moderate-to-severe OSA than in those with primary snoring/mild OSA, even after adjustment for age and gender [OR?=?3.44 (95% CI 1.44 to 8.24; p?=?0.006)]. Concentrations of serum lipids in obese children were not associated with severity of OSA. HDL cholesterol was 48.5?±?8.7 mg/dL in subjects with moderate-to-severe OSA and 50.0?±?11.1 mg/dL in children with primary snoring/mild OSA (p?=?0.519).

Conclusions

HDL cholesterol levels are inversely related to severity of OSA in non-obese children with snoring.     

P wave duration and dispersion in Holter electrocardiography of patients with obstructive sleep apnea

Purpose

The underlying mechanisms of the association between obstructive sleep apnea (OSA) and atrial fibrillation (AF) remained unclear. We investigated P wave parameters as indicators of atrial conduction status among OSA patients.

Methods

We studied 42 untreated OSA patients, categorized into mild (6), moderate (18), and severe (18) OSA based on the apnea/hypopnea index (AHI) and 18 healthy controls. Twenty-four-hour Holter electrocardiography was applied to measure P wave parameters including P wave duration and P wave dispersion; difference between the maximum (P-max) and minimum (P-min) measured P wave duration.

Results

Mean P wave duration ranged from 110.2?±?9.3 ms in mild OSA patients to 121.1?±?15.4 ms in severe OSA patients and was 113.4?±?10.0 ms in controls with no significant difference among the groups, P?=?0.281. P wave dispersion and P-max were significantly longer in those with moderate OSA (68.0?±?9.3 and 154.2?±?9.3 ms) and those with severe OSA (71.6?±?13.7 and 157.2?±?13.3 ms) than controls (52.6?±?15.3 and 142.1?±?15.4 ms), P?r?=?0.407, P?=?0.012) and P wave dispersion (r?=?0.431, P?=?0.008). With linear regression analysis controlling for age, gender, and BMI, the AHI was independently associated with P wave dispersion (β?=?0.482, P?=?0.002).

Conclusions

Using Holter monitoring for measurement of P wave parameters, this study showed an association of OSA with prolonged P-max and P wave dispersion. These results indicate that patients with OSA have disturbances in atrial conduction associated with OSA severity. Repeating this study in a larger sample of patients is warranted.     

Atrial Fibrillation Promotion With Long-Term Repetitive Obstructive Sleep Apnea in a Rat Model

Background

Obstructive sleep apnea (OSA) importantly contributes to the occurrence of atrial fibrillation (AF) in humans, but the mechanisms are poorly understood. Experimental research has provided insights into AF promotion by acute OSA episodes. However, patients with OSA usually have frequent nocturnal episodes for some time before manifesting AF.

Objectives

The goal of this study was to test the hypothesis that repetitive OSA causes cardiac remodeling that predisposes to AF.

Methods

We mimicked OSA by using a mechanical ventilator and closing the airway at end-expiration with a 3-way stopcock (OSA rats). Matched control groups included rats with the ventilator stopped but airway left open (open airway rats) and continuously ventilated rats (sham rats). OSA rats were exposed to 20 consecutive 2-min cycles of 40 s of apnea/80 s of ventilation per day, 5 days per week for 4 weeks.

Results

OSA significantly increased the duration of AF from (median [interquartile range]) 2.6 s [1.9 s to 8.9 s] (shams) and 16 s [1.8 s to 93 s] (open airway) to 49s [34 s to 444 s]. AF inducibility increased to 56% (9 of 16) of OSA rats; this is up from 15% (2 of 13) and 13% (2 of 15) in open airway and sham rats, respectively (p < 0.05). OSA rats exhibited substantial atrial conduction slowing on optical mapping, along with connexin-43 down-regulation on both quantitative immunofluorescence (expression reduced by 58% vs sham rats) and Western blot (reduced by 38%), as well as increased atrial fibrous tissue content (by 71%). OSA also caused left ventricular hypertrophy, dilation, and diastolic dysfunction and enhanced AF inducibility during superimposed acute OSA episodes to 82.4% of rats.

Conclusions

Chronically repeated OSA episodes cause AF-promoting cardiac remodeling, with conduction abnormalities related to connexin dysregulation and fibrosis playing a prominent role. This novel animal model provides mechanistic insights into an important clinical problem and may be useful for further exploration of underlying mechanisms and therapeutic approaches.     

Relation of atrial electromechanical delay to P-wave dispersion on surface ECG using vector velocity imaging in patients with hypertrophic cardiomyopathy

Objectives

Heterogeneity of structural and electrophysiologic properties of atrial myocardium is common characteristic in hypertrophic cardiomyopathy (HCM). We assessed the dispersion of atrial refractoriness on surface ECG using P-wave dispersion (PWD) and its relation to atrial electromechanical functions using vector velocity imaging (VVI) in HCM population.

Methods

Seventy-nine HCM patients (mean age: 43.7 ± 13 years, 67% male) were compared with 25 healthy individuals as control. P-wave durations, P_max and P_min, P-wave dispersion (PWD), and P terminal force (PTF) were measured from 12-lead ECG. LA segmental delay (TTP-d) and dispersion (TTP-SD) of electromechanical activation were derived from atrial strain rate curves.

Results

HCM patients had longer PR interval, PW duration, higher PWD, PTF, QT_c compared to control (p < .001). HCM patients were classified according to presence of PWD into two groups, group I with PWD > 46 ms (n = 25) and group II PWD ≤ 46 ms (n = 54). Group I showed higher prevalence of female gender, higher PTF, QTc interval, left ventricular outflow tract (LVOT) obstruction, p < .01, LVOT gradient (p < .001), LV mass index (p < .01), E/E' (p < .01), and severe mitral regurgitation (p < .001). Moreover, PWD was associated with increased atrial electromechanical delay (TTP-d) and LA mechanical dyssynchrony (TTP-SD), p < .001. LA segmental delay and dispersion of electromechanical activation were distinctly higher among HCM patient.

Conclusion

PWD is simple ECG criterion, and it is associated with more severe HCM phenotype and LA electromechanical delay while PTF is linked only to atrial remodeling.

     

Tissue Doppler atrial conduction times and electrocardiogram interlead P-wave durations with varying severity of obstructive sleep apnea

Objectives

Obstructive sleep apnea (OSA) has been reported to be associated with an increased risk of atrial fibrillation. The aim of this study was to investigate atrial electromechanical couplings in patients with OSA and the relationship between these parameters and P-wave dispersion (Pd).

Methods

One hundred twenty-six patients were enrolled in this study. All patients underwent polysomnographic examination. The apnea-hypopnea index (AHI) was defined as the number of apneas and hypopneas per hour of sleep. An AHI score of 5 or more was diagnosed as OSA, and an AHI score of less than 5 was diagnosed as OSA (−). Thirty-nine of the patients had an AHI score of less than 5 (group 1), 42 of the patients had AHI score between 5 and 30 (mild and moderate, group 2), 45 of the patients had an AHI score more than 30 (severe, group 3). Atrial electromechanical coupling (PA), intra-atrial, and interatrial electromechanical delay were measured with tissue Doppler imaging. P-wave dispersion was calculated from 12-lead electrocardiogram.

Results

Maximum P-wave duration was higher in group 3 compared with groups 2 and 1 (126.0 ± 16.7 vs 111.0 ± 12.5 [P < .001] and 126.0 ± 16.7 vs 99.9 ± 10.0 [P < .001], respectively). Maximum P-wave duration was higher in group 2 than in group 1 (111.0 ± 12.5 vs 99.9 ± 10.0, P < .001). P-wave dispersion was higher in group 3 compared with groups 2 and 1 (50.9 ± 11.5 vs 37.0 ± 8.6 [P < .001] and 50.9 ± 11.5 vs 27.9 ± 6.8 [P < .001], respectively). P-wave dispersion was higher in group 2 than in group 1 (37.0 ± 8.6 vs 27.9 ± 6.8, P < .001). Minimum P-wave duration did not differ between the groups. Atrial PA at the left lateral mitral annulus (lateral PA), septal mitral annulus (septal PA), and right ventricular tricuspid annulus (RV PA) were significantly higher in group 3 than in group 2 (P < .001, P = .001, and P = .009, respectively). Lateral PA, septal PA, and RV PA were higher in group 2 compared with group 1 (P < .001, P = .003, and P = .009, respectively). Interatrial electromechanical delay (lateral PA − RV PA) was significantly longer in group 3 compared with groups 2 and 1 (33.6 ± 12.1 vs 22.4 ± 9.4 [P < .001] and 33.6 ± 12.1 vs 14.9 ± 9.2 [P < .001], respectively). Interatrial electromechanical delay was longer in group 2 than in group 1 (22.4 ± 9.4 vs 14.9 ± 9.2, P = .001). There was a positive correlation between AHI and Pd, lateral PA, septal PA, RV PA, interatrial electromechanical delay, and left-sided intra-atrial electromechanical delay.

Conclusion

Prolongation of electromechanical delay and increased Pd are associated with apnea-hypopnea index (AHI) and hence the severity of disease.     

Reverse atrial electrical remodelling induced by continuous positive airway pressure in patients with severe obstructive sleep apnoea

Background

Obstructive sleep apnoea (OSA) is associated with cardiovascular morbidity and mortality, including atrial arrhythmias. Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA; its impact on atrial electrical remodelling has not been fully investigated. Signal-averaged p-wave (SAPW) duration is an accepted marker for atrial electrical remodelling.

Objective

The objective of this study is to determine whether CPAP induces reverse atrial electrical remodelling in patients with severe OSA.

Methods

Consecutive patients attending the Sleep Disorder Clinic at Kingston General Hospital underwent full polysomnography. OSA-negative controls and severe OSA were defined as apnoea–hypopnea index (AHI)?<?5 events/hour and AHI?≥?30 events/hour, respectively. SAPW duration was determined at baseline and after 4–6 weeks of CPAP in severe OSA patients or without intervention controls.

Results

Nineteen severe OSA patients and 10 controls were included in the analysis. Mean AHI and minimum oxygen saturation were 41.4?±?10.1 events/hour and 80.5?±?6.5 % in severe OSA patients and 2.8?±?1.2 events/hour and 91.4?±?2.1 % in controls. At baseline, severe OSA patients had a greater SAPW duration than controls (131.9?±?10.4 vs 122.8?±?10.5 ms; p?=?0.02). After CPAP, there was a significant reduction of SAPW duration in severe OSA patients (131.9?±?10.4 to 126.2?±?8.8 ms; p?<?0.001), while SAPW duration did not change after 4–6 weeks in controls.

Conclusion

CPAP induced reverse atrial electrical remodelling in patients with severe OSA as represented by a significant reduction in SAPW duration.     

Assessment of atrial conduction time in patients with polycystic ovary syndrome

Background

Polycystic ovary syndrome (PCOS) is closely related to increased cardiovascular risk in women of reproductive age. Atrial conduction abnormalities in these patients have not been investigated in terms of atrial electromechanical delay measured by tissue Doppler imaging (TDI) as an early predictor of atrial fibrillation development. The aim of this study was to evaluate whether TDI-derived atrial conduction time is prolonged in PCOS.

Methods

The study included 51 patients with PCOS and 48 age-matched healthy controls. P-wave dispersion (PWD) was calculated on the 12-lead surface electrocardiogram. Systolic and diastolic left ventricular (LV) functions, atrial electromechanical coupling, intraatrial and interatrial electromechanical delays were measured with conventional echocardiography and TDI.

Results

PWD was higher in PCOS women (50.45?±?3.7 vs 34.73?±?6.7 ms, p?=?0.008). Interatrial and intraatrial electromechanical delay were found longer in patients with PCOS compared to controls (41.9?±?9.0 vs 22.2?±?6.6 ms, p?p?r?=?0.54, p?C-reactive protein levels (r?=?0.68, p?r?=?0.53, p?r?=?0.31, p?=?0.04; r?=?0.37, p?=?0.021, respectively) and negatively correlated with flow propagation velocity (r?=??0.38, p?=?0.014).

Conclusion

This study shows that atrial electromechanical delay is prolonged in PCOS patients. Atrial electromechanical delay prolongation is related to low-grade inflammation, insulin resistance, and LV diastolic dysfunction in PCOS.     

Oxidative stress and inflammatory markers in the exhaled breath condensate of children with OSA

Introduction

Obstructive sleep apnea (OSA) in children has been associated with systemic inflammation and oxidative stress. Limited evidence indicates that pediatric OSA is associated with oxidative stress and inflammation in the airway.

Objective

The objective of this study is to assess the hypothesis that levels of oxidative stress and inflammatory markers in the exhaled breath condensate (EBC) of children with OSA are higher than those of control subjects.

Methods

Participants were children with OSA and control subjects who underwent overnight polysomnography. Morning levels of hydrogen peroxide (H₂O₂) and sum of nitrite and nitrate (NO _x ) in EBC of participants were measured.

Results

Twelve subjects with moderate-to-severe OSA (mean age?±?standard deviation: 6.3?±?1.7?years; apnea?Chypopnea index??AHI, 13.6?±?10.1 episodes/h), 22 subjects with mild OSA (6.7?±?2.1?years; AHI, 2.8?±?1 episodes/h) and 16 control participants (7.7?±?2.4?years; AHI, 0.6?±?0.3 episodes/h) were recruited. Children with moderate-to severe OSA had higher log-transformed H₂O₂ concentrations in EBC compared to subjects with mild OSA, or to control participants: 0.4?±?1.1 versus ?0.9?±?1.3 (p?=?0.015), or versus ?1.2?±?1.2 (p?=?0.003), respectively. AHI and % sleep time with oxygen saturation of hemoglobin <95% were significant predictors of log-transformed H₂O₂ after adjustment by age and body mass index z score (p? x levels.

Conclusions

Children with moderate-to-severe OSA have increased H₂O₂ levels in morning EBC, an indirect index of altered redox status in the respiratory tract.     

Obstructive sleep apnea causes oxidative damage to plasma lipids and proteins and decreases adiponectin levels

Pupose  

Obstructive sleep apnea (OSA) is associated with various metabolic disorders, and oxidative stress was suggested to play an important role. In the present study, we aimed to investigate serum adiponectin and oxidative stress markers, especially protein carbonyls, and to evaluate the correlation between these parameters and lipid, insulin and fasting glucose concentrations in OSA patients and controls.     

Quality of life in obstructive sleep apnea is related to female gender and comorbid insomnia

Purpose

Obstructive sleep apnea (OSA) is a common sleep disorder affecting health-related quality of life (QoL), and OSA severity is not a reliable indicator for QoL. The aim of this study was (1) to evaluate the impact of gender on QoL and (2) to identify the predictors of QoL in OSA patients.

Methods

World Health Organization Quality of Life Scale short form (WHOQOL-Bref) was used for evaluating QoL in OSA patients undergoing polysomnography in sleep laboratory of a university hospital.

Results

Out of 197 patients (age 50.4?±?12.1 years, AHI 38.5?±?28.4/h), 139 (70.6%) were men and 79.2% had moderate-to-severe OSA. Female gender, increased BMI, higher Epworth sleepiness score (ESS), and lower oxygen saturations were associated significantly with poor QoL in terms of all domains (physical, psychological, social relationship, and environmental) of WHOQOL-Bref questionnaire. The indicators of OSA severity (AHI and ODI) correlated negatively only with the physical domain. The subjects with comorbid insomnia and OSA had lower physical and social scores than subjects with no insomnia, and women with insomnia had significantly worse QoL scores in all domains than the others. In the multivariate linear regression analysis, female gender, comorbid insomnia, increased sleepiness, and higher BMI were significantly associated with poor QoL.

Conclusions

Female gender, comorbid insomnia, and daytime sleepiness were the outstanding factors affecting health-related QoL negatively in OSA. Besides, the impact of OSA on QoL may be explained by the presence of daytime sleepiness rather than OSA severity.

     

The efficacy of oral appliances in the treatment of severe obstructive sleep apnea

Objectives  

The purpose of this study is to evaluate the efficacy of oral appliance (OA) treatment for subjects with severe obstructive sleep apnea (OSA) and to determine the dental parameters associated with treatment outcomes.     

Fixed-pressure nCPAP in patients with obstructive sleep apnea (OSA) syndrome and chronic obstructive pulmonary disease (COPD): a 24-month follow-up study

Purpose  

The aim of this study was to investigate the time course of body weight, daytime sleepiness, and functional cardiorespiratory parameters in patients with both chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea syndrome (OSA), after institution of domiciliary nasal continuous positive airway pressure (nCPAP).     

Analysis of anatomical and functional determinants of obstructive sleep apnea

Purpose

Craniofacial abnormalities have an important role in the occurrence of obstructive sleep apnea (OSA) and may be particularly significant in Asian patients, although obesity and functional abnormalities such as reduced lung volume and increased airway resistance also may be important. We conducted simultaneous analyses of their interrelationships to evaluate the relative contributions of obesity, craniofacial structure, pulmonary function, and airway resistance to the severity of Japanese OSA because there are little data in this area.

Methods

A cross-sectional observational study was performed on 134 consecutive Japanese male patients. A sleep study, lateral cephalometry, pulmonary function tests, and impulse oscillometry (IOS) were performed on all patients.

Results

Age, body mass index (BMI), position of the hyoid bone, and proximal airway resistance on IOS (R20) were significantly related to the apnea/hypopnea index (AHI) (p?<?0.05) in multiple regression analysis. Subgroup analysis showed that, for moderate-to-severe OSA (AHI????15 events/h), neck circumference and R20 were predominantly related to AHI, whereas for non-to-mild OSA (AHI?<?15 events/h), age and expiratory reserve volume were the predominant determinants. In obese subjects (BMI????25?kg/m²), alveolar?Carterial oxygen tension difference, position of the hyoid bone, and R20 were significantly associated with AHI, whereas age alone was a significant factor in nonobese subjects (BMI?<?25?kg/m²).

Conclusions

Aside from age and obesity, anatomical and functional abnormalities are significantly related to the severity of Japanese OSA. Predominant determinants of AHI differed depending on the severity of OSA or the magnitude of obesity.     

The Relationship Among Atrium Electromechanical Interval,Insulin Resistance,and Metabolic Syndrome

Background

Metabolic syndrome (MS) is an important risk factor of atrial fibrillation. However, an understanding of the adverse effects of MS on left atrial (LA) functional assessment in terms of electromechanical interval, a convenient parameter that can reflect the process of LA remodelling, has been lacking. The goal of this study was to investigate the association between electromechanical interval and MS.

Methods

In all, 337 patients (91 with MS) with mean age of 51.9 ± 9.0 years were enrolled. Metabolic syndrome was defined by National Cholesterol Education Program–Adult Treatment Panel III score. Insulin resistance was assessed by the homeostasis model assessment–insulin resistance method. The electromechanical interval, defined as the time from initiation of P wave deflection to peak of mitral inflow Doppler A wave (PA-PDI), was measured.

Results

Patients with MS had significantly longer PA-PDI intervals compared with those of patients without MS (131.0 ± 12.4 milliseconds vs 123.2 ± 14.0 milliseconds, P < 0.001). Longer PA-PDI intervals were observed in subjects with higher metabolic scores (P < 0.05). In patients with small LA size, PA-PDI intervals, but not LA dimensions, were significantly different between groups with and without MS (P < 0.05). Additionally, PA-PDI interval was positively correlated with insulin resistance (r = 0.267, P < 0.001).

Conclusions

PA-PDI intervals were longer in patients with MS compared with those of patients without MS and tracked with insulin resistance. PA-PDI may be a useful clinical parameter to represent the degree of atrial remodelling in subjects with metabolic derangements.     

Treatment of obstructive sleep apnea reduces arterial stiffness

Purpose  

A close relationship between obstructive sleep apnea (OSA) and atherosclerosis has been reported, but it is still discussed controversially whether OSA affects vascular function and structure independently. Therefore, we prospectively investigated the independent impact of OSA and its treatment on arterial stiffness.     

Effects of obstructive sleep apnea on serum brain-derived neurotrophic factor protein,cortisol, and lipid levels

Objectives  

Obstructive sleep apnea (OSA) is a sleep-disordered breathing leading to vascular endothelial cells dysfunction, cognitive impairment, and abnormal lipid metabolism. serum brain-derived neurotrophic factor (BDNF) protein, cortisol, and lipid levels in OSA were investigated.     

Anemia of aging and obstructive sleep apnea

Introduction  

World Health Organization defined anemia of aging (AOA) when men and women greater than 65 years, respectively, have unexplained hemoglobin (Hgb) less than 13 and 12 g/dl. Recent evidence suggests that this is likely a chronic inflammatory process involving interleukins (IL) 6, 12, and C-reactive protein. Among elderly with obstructive sleep apnea (OSA), hypoxic stimulation of erythropoiesis may obscure AOA. Treatment of OSA may paradoxically restore AOA. We sought to identify OSA and AOA coexistence and OSA treatment AOA interaction.     

The relationship between high-sensitivity C-reactive protein levels and the severity of obstructive sleep apnea

Background and objective  

There is an increased risk of cardiovascular and cerebrovascular events in patients with obstructive sleep apnea (OSA). High-sensitivity C-reactive protein (hs-CRP) is a marker that predicts atherosclerotic complications. However, there are contradictory results about the correlation between serum hs-CRP levels and OSA severity. The purpose of this work was to evaluate the relationship between hs-CRP levels and the severity of OSA in newly diagnosed OSA patients.