Sleep-disordered breathing and chronic atrial fibrillation.

BACKGROUND: Little has been known about the prevalence of sleep apnea in patients with atrial fibrillation (AF). Studies have suggested that the prevalence of AF is increasing in patients with sleep-disordered breathing. We hypothesize that the prevalence of OSA is higher in chronic persistent and permanent AF patients than a sub-sample of the general population without this arrhythmic disorder. OBJECTIVE: Evaluate the frequency of Obstructive Sleep Apnea in a sample of chronic AF compared to a sub-sample of the general population. METHODS: Fifty-two chronic AF patients aged (60.5 +/- 9.5, 33 males) and 32 control (aged 57.3 +/- 9.6, 15 males). All subjects were evaluated by a staff cardiologist for the presence of medical conditions and were referred for polysomnography. The differences between groups were analyzed by ANOVA for continuous variables, and by the Chi-square test for dichotomous variables. Statistical significance was established by alpha=0.05. RESULTS: There were no differences in age, gender, BMI, sedentarism, presence of hypertension, type 2 diabetes mellitus, abdominal circumference, systolic and diastolic blood pressure, and sleepiness scoring between groups. Despite similar BMI, AF patients had a higher neck circumference compared to control group (39.9cm versus 37.7cm, p=0.01) and the AF group showed higher percentage time of stage 1 NREM sleep (6.4% versus 3.9%, p=0.03). Considering a cut-off value for AHI >= 10 per hour of sleep, the AF group had a higher frequency of OSA compared to the control group (81.6% versus 60%, p=0.03). All the oxygen saturation parameters were significantly worse in the AF group, which had lower SaO(2) nadir (81.9% versus 85.3%, p=0.01) and mean SaO(2) (93.4% versus 94.3%, p=0.02), and a longer period of time below 90% (26.4min versus 6.7min, p=0.05). CONCLUSION: Sleep-disordered breathing is more frequent in chronic persistent and permanent AF patients than in age-matched community dwelling subjects.

Variability of respiratory effort in relation to sleep stages in normal controls and upper airway resistance syndrome patients.

OBJECTIVE: Investigation of the role of sleep states on the respiratory effort of controls and subjects with upper airway resistance syndrome (UARS) using nasal cannula/pressure transducer system and esophageal manometry. PATIENTS AND METHODS: One night's monitoring of sleep and breathing, including the determination of peak end inspiratory esophageal pressure (respiratory effort) with esophageal manometry and flow limitation with nasal cannula. Analysis of the data, breath-by-breath, using visual inspection and a computerized program. Setting - a university sleep laboratory. Patients were nine men with UARS and nine control men matched for age, ethnicity, and body mass index. RESULTS: A modulation of respiratory effort by sleep state and stages is seen in all subjects, the lowest noted during REM sleep and the highest associated with Slow Wave Sleep. When total nocturnal breaths are investigated, a significant difference between peak end inspiratory esophageal pressure [(Pes)-considered as an index of respiratory effort] is noted between normal subjects and UARS. Two specific breathing patterns, seen primarily in UARS patients, are NREM sleep stage dependent. Crescendos (defined as more negative peak end inspiratory Pes with each successive abnormal breath) occur mostly during stages 1-2 NREM sleep, while segments consisting of regular and continuous, breath-after-breath, high respiratory efforts are associated with Slow Wave Sleep. Depending on sleep stage, visually scored arousal response displays differences in Pes negativity. The termination of the abnormal breathing pattern, always well defined with Pes, is not necessarily associated with a pattern of 'flow limitation' at the nasal cannula tracing, even when a visually scored EEG arousal is present. CONCLUSIONS: UARS patients have significantly more breaths, with more negative peak end inspiratory Pes, than do control subjects. The modulation of peak end inspiratory Pes (an index of respiratory effort) by sleep stage and state differs in UARS patients and control subjects. The nasal cannula/pressure transducer system may not detect all abnormal breathing pattern during sleep. As indicated by the visual sleep scoring, repetitive arousals may lead to more or less severe sleep fragmentation.

Arousal, EEG spectral power and pulse transit time in UARS and mild OSAS subjects.

OBJECTIVES: Upper airway resistance syndrome (UARS) and obstructive sleep apnea syndrome (OSAS) are associated with arousals and autonomic activation. Pulse transit time (PTT) has been used to recognize transient arousals. We examined the accuracy of PTT to recognize arousals, and the relationship between PTT deflection and visual and non-visual arousals. METHODS: Ten UARS and 10 mild OSAS subjects were studied via polysomnography including measurement of esophageal pressure. Electroencephalogram (EEG) spectral power was obtained from central leads. Seven types of events were identified, depending upon the presence or absence of: a sleep-related respiratory event (SRRE), i.e. apnea, hypopnea, and abnormal breathing effort; a PTT signal; or a visually scored arousal (>1.5s). RESULTS: One thousand four hundred forty-six events were identified in 20 subjects. Fifty-nine percent of all SRREs were associated with a PTT signal and a visual EEG arousal. Nineteen percent of SRREs had no EEG arousals at their termination, and 7.4% had no associated PTT signal. Delta power was significantly increased when non-visual EEG arousals were scored. The time delay for PTT was determined by the presence or absence of EEG arousal. The sensitivity of PTT to recognize EEG arousal was 90.4% and the specificity was 16.8%. The sensitivity and specificity of PTT to recognize SRRE was 90.7 and 21.9%, respectively. CONCLUSIONS: These results preclude the use of PTT by itself. SRREs induce an activation with positive PTT response but without arousal in 14% of cases. This PTT response, however, is much slower than that occurring with arousal. UARS and mild OSAS do not respond in the same way to SRREs, particularly during rapid eye movement sleep.

Sleep and wakefulness in somnambulism: a spectral analysis study.

OBJECTIVE: The sleep structure and the dynamics of EEG slow-wave activity (SWA) were investigated in 12 young adults and age- and gender-matched controls. METHODS: Polysomnography was performed in subjects with well-documented chronic sleepwalking and in matched controls. Blinded visual scoring was performed using the international criteria from the Rechtschaffen and Kales atlas [A manual of standardized technology, techniques and scoring systems for sleep stages of human subjects. Los Angeles: UCLA Brain Information Service, Brain Research Institute, 1968.] and by determining the presence of microarousals as defined in the American Sleep Disorders Association (ASDA) atlas [Sleep 15 (1992) 173.]. An evaluation of SWA overnight was performed on total nocturnal sleep to determine if a difference existed between groups of subjects, since sleepwalking usually originates with slow-wave sleep. Investigation of the delta power in successive nonoverlapping 4-second windows in the 32 seconds just prior to EMG activity associated with a confusional arousal was also conducted. One central EEG lead was used for all analyses. RESULTS: Somnambulistic individuals experienced more disturbed sleep than controls during the first NREM-REM sleep cycle. They had a higher number of ASDA arousals and presented lower peak of SWA during the first cycle that led to a lower SWA decline overnight. When the investigation focused on the short segment immediately preceding a confusional arousal, they presented an important increase in the relative power of low delta (0.75-2 Hz) just prior to the confusional arousal. CONCLUSION: Sleepwalkers undergo disturbed nocturnal sleep at the beginning of the night. The increased power of low delta just prior to the confusional arousal experienced may not be related to Stages 3-4 NREM sleep. We hypothesize that it may be translated as a cortical reaction to brain activation.

[Generalized anxiety disorder in a population aged 80 years and older]. / Transtorno de ansiedade generalizada em idosos com oitenta anos ou mais.

OBJECTIVE: To describe the prevalence of generalized anxiety disorder (GAD) in a community-dwelling population aged 80 years and older. Also to compare sleep patterns, cognitive function and prevalence of other psychiatric conditions between healthy controls and GAD subjects. METHODS: DSM-IV criteria were used to diagnose GAD. A representative random sample of 77 community-dwelling subjects (35%), aged 80 years or more from the rural southern county of Veranopolis, Brazil, was selected. Sleep patterns were assessed using the Pittsburgh Sleep Quality Index and a 2-week sleep/wake diary. Five neuropsychological tests (Buschke-Fuld Selective Reminding Test, CERAD word list, verbal fluency test and two sub-tests of the Wechsler memory scale) were used for cognitive evaluation. RESULTS: The estimated GAD prevalence was 10.6 percent. GAD was associated with major depression, with a significant greater number of depressive symptoms as measured by the Geriatric Depression Scale and with a significant more frequent occurrence of minor depression. Sleeping patterns and cognition function among GAD subjects were not compromised. The severity of physical diseases was similar in both GAD subjects and healthy controls. GAD was associated with a significantly lower health-related quality of life. CONCLUSIONS: In comparison with previous studies, the prevalence of GAD is higher in the studied population. This disorder is frequently associated with both depressive symptoms and a lower health-related quality of life.

Association between body mass index and sleep duration assessed by objective methods in a representative sample of the adult population.

INTRODUCTION: Sleep duration has been associated with overweight individuals in many epidemiological studies; however, few studies have assessed sleep using objective methods. Our study was designed to evaluate the association between body mass index (BMI) and sleep duration measured by actigraphy (Acti), polysomnography (PSG) and the Pittsburgh sleep quality index questionnaire (PSQIO). Furthermore, we evaluated other biochemical and polysomnographic parameters. METHODS: A representative sample of 1042 individuals from Sao Paulo, Brazil, including both genders (20-80 yrs), participated in our protocol. Weight and other anthropometric parameters were measured at the onset of the study. Sleep duration was calculated by Acti, PSG, and the PSQIQ. The population was sorted by sleep duration, body, slow wave sleep (SWS) and REM sleep (REMS) duration subsets. In addition, other biochemical and polysomnographic parameters were analyzed. Differences between population subsets were analyzed by one-way analysis of variance (ANOVA). Linear regression analysis was performed between sleep and anthropometric parameters. RESULTS: Shorter sleep duration was associated with higher BMI and waist and neck circumference when measured by Acti and PSG (p<0.05). Lower leptin levels were associated with short sleep in normal-weight (BMI>18 and ⩽25) individuals (p<0.01). The association between short sleep duration Acti and higher BMI was present when apnea-hypopnea index (AHI) was less than 15 (p=0.049). Shorter REMS and SWS also were associated with higher BMI (p<0.01). Normal-weight individuals tended to sleep longer, have higher sleep efficiency and longer SWS and REMS than obese individuals (Acti, PSG; p=0.05). Sleep duration was negatively correlated with BMI (Acti, PSG; p<0.05). Short SWS and REMS were associated with higher cardiovascular risk factors (p<0.05). CONCLUSION: Shorter sleep, SWS, and REMS duration were associated with higher BMI, central adiposity measurements, and cardiovascular risk factors when measured by objective methods.

Impact of continuous positive airway pressure treatment on left atrial volume and function in patients with obstructive sleep apnoea assessed by real-time three-dimensional echocardiography.

BACKGROUND: Obstructive sleep apnoea (OSA) has been reported as a predictor of left ventricle (LV) diastolic dysfunction and left atrium (LA) remodelling. The aim of this study is to evaluate the impact of OSA treatment with a continuous positive airway pressure device (CPAP) on the LA volume and function, as well as on the LV diastolic function. METHODS: In total, 56 OSA patients were studied. All patients underwent real-time three-dimensional (RT3DE) and two-dimensional echocardiogram with tissue Doppler evaluation in order to estimate LA volumes, function and LV diastolic performance. A total of 30 patients with an apnoea-hypopnoea index greater than 20 were randomly selected to receive sham CPAP (n = 15) or effective CPAP (n = 15) for 24 weeks. They underwent echo examination on three different occasions: at baseline, after 12 weeks and 24 weeks of CPAP or sham CPAP. RESULTS: In the effective CPAP group we observed the following changes from the baseline to the 24-week echo evaluation: (a) a reduction in the E/E' ratio (10.3 (1.9) to 7.9 (1.3), p = 0.03); (b) an increase in the LA passive emptying fraction (28.8% (11.9%) to 46.8% (9.3%), p = 0.01); and (c) a reduction in the LA active emptying fraction (42.7% (11.5%) to 25.7 (15.7), p<0.01). In the sham group, there were no changes from the baseline to the 24-week echo. We found a positive correlation between 24 week/baseline LA active emptying volume and 24 week/baseline E/E' ratios (r = 0.40, p<0.05) and a negative correlation between 24 week/baseline LA passive emptying volume and 24 week/baseline E/E' ratios (r = -0.53, p<0.05). No significant changes were found on LA total emptying fraction. CONCLUSION: CPAP improved LV diastolic function and LA passive emptying, but not LA structural variables in OSA patients. TRIAL REGISTRATION NUMBER: NCT00768807.

Methodology in clinical sleep research.

This review presents traditional and cutting-edge interventions in sleep research, including descriptions of the relationship of rapid eye movement-non-rapid eye movement sleep with the autonomous nervous system, and dream research methodology. Although sleep and dreaming are overlapping and non- separable phenomena, they are not typically addressed simultaneously in the scientific sleep research literature. Therefore, a more extensive overview of dream research has been included with a focus on objective dream content analysis and the theory of neurocognitive analysis. A bridge is made between dream content analysis and current sleep research methodologies.

Treatment of periodic leg movements with a dopaminergic agonist in subjects with total spinal cord lesions.

OBJECTIVE: To investigate the effect of L-dopa on the PLM/h index of spinal cord injured subjects. SETTING: São Paulo, Brazil. METHODS: Thirteen male volunteers with spinal cord section between T7 - T12, and mean age of 31.6+/-8.3 years participated in the study. L-dopa or placebo were administered for 30 days, 1 h before the volunteers went to sleep, in a double blind, crossover design. Polysomnographic recordings were performed on ten occasions: Phase 1: Basal night, following an adaptation night at the sleep laboratory; phase 2: after 1, 7, 21 and 30 days of L-dopa administration; phase 3: first night of L-dopa or placebo withdrawal; phase IV: 1, 7, 21 and 30 days after placebo ingestion. RESULTS: The index of PLM/h on the first night of L-dopa or placebo withdrawal (phase III) was lower than on both the basal night and the first night of L-dopa treatment. At the time of polysomnographic analysis, volunteers were divided into two groups: index of PLM/h below five and those whose index was above five. Comparison between L-dopa and placebo treatments revealed that only those volunteers with an index above five revealed a reduction in PLM in L-dopa. CONCLUSION: These results indicate that despite the spinal cord lesions, L-dopa treatment is capable of minimizing PLM during sleep.

Correlation between K complex, periodic leg movements (PLM), and myoclonus during sleep in paraplegic adults before and after an acute physical activity.

K complex is the characteristic wave of stage II of sleep. The relationship between periodic limb movements (PLM) and the restless legs syndrome (RLS), and the incidence of K complexes and alpha activity has been previously described. The aim of the present study was to evaluate the effect of an acute physical activity upon K complex, PLM, and myoclonus during sleep in individuals who were paraplegic. We evaluated 84 polysomnograms from 28 volunteers with a spinal cord injury at the level of T7-T12, obtained during three consecutive nights. On day 3, the volunteers were submitted to a test of maximum effort (manual cycloergometer, with the equipment Cybex Met 300, with a progressive load increase of 12.5 w, every 2 min). The analysis of the polysomnographic recordings showed a positive correlation between the incidence of K complex and limb movements on nights 1, 2 and 3. Similarly, a correlation between the incidence of K complex and myoclonus was observed on nights 1, 2 and 3. An increased incidence of the total K complex was seen on night 3, 36 h after the test maximum effort. Both total K complex and K complex/h were reduced on night 2, compared to basal recording (night 1). There was a reduction of sleep latency on night 2, whereas total sleeping time increased progressively on night 3, as well as REM phase on nights 2 and 3. These findings indicate that physical activity can effect or modulate the incidence of K complex and suggest that a positive correlation between PLM and K complex may occur in those who are paraplegic from a spinal cord injury. In conclusion, sleep can be consolidated after physical activity.

Normal pregnancy, daytime sleeping, snoring and blood pressure.

Objective: Investigation of daytime sleepiness, blood pressure changes and presence of sleep disordered breathing, in healthy young women during pregnancy.Methods: Young, healthy pregnant women between 18 and 32 years of age, seen in three different prenatal care clinics, were enlisted in a prospective study divided in two parts: part 1 of the study consisted of completing a standardized questionnaire on past and present sleep disorders. It also included filling out visual analog scales (VAS) for daytime sleepiness and snoring by the subject and bed partner. Blood pressure measurement was performed at 9 AM as per the WHO protocol. Similar data were collected again at the 6-month prenatal visit and at the 3-month post-delivery visit. At the 6-month visit, ambulatory monitoring of nocturnal sleep using a portable six-channel recorder (Edentrace((R))) was performed at home. Part 2 involved a subgroup of subjects that were randomly selected after stratification based on results of VAS and ambulatory monitoring. It included 1 night of nocturnal polysomnography with esophageal manometry and 24 h of ambulatory BP monitoring with portable equipment with cuff inflation every 30 min.Results: Of the 267 women who participated in part 1 of the study, only 128 consented to enroll in part 2, from which 26 were selected to undergo polysomnography. At the 6-week prenatal visit 37.45% of the subjects reported daytime sleepiness of variable severity. At the 6-month visit, this was noted in 52% of the subjects. Bed-partners reported chronic, loud snoring prior to pregnancy in 3.7% of the study population, but this increased to 11.8% at the 6-month visit. Blood pressure (BP) remained below the pathological range, i.e. less than 150/95 mm Hg, during the entire pregnancy. However, ambulatory monitoring indicated that 37 women, including the loud chronic snorers, had some minor SaO(2) drops during sleep and this same group presented the largest increase in BP between the 6th week and the 6th month prenatal visits. Part 2 included 26 women, 13 from the above identified 37 women and 13 from the rest of the group, chosen randomly, age and body mass index (BMI) matched. Polysomnography did identify two abnormal breathing patterns during sleep: (1) esophageal pressure 'crescendos' associated predominantly with stage 1 and 2 NREM sleep, and (2) 'abnormal sustained efforts' seen predominantly with delta sleep. These abnormal breathing patterns were noted during a significantly longer time during sleep. This group of women with the abnormal breathing patterns were not only chronic snorers but also had significantly higher systolic and diastolic BP increases when compared to the 13 other non-snorers. Six out of the 13 snorers were 'non-dippers' at the 24-h BP recording.Conclusion: Abnormal breathing during sleep (that is frequently, but not always, associated with loud, chronic snoring, and may be a consequence of edema induced by hormonal changes associated with pregnancy), can be seen in otherwise healthy young pregnant women. It may contribute to the symptom of daytime sleepiness. The changes in blood pressure noted were of no pathological significance in our population but could be an added risk factor in high-risk pregnancies.

Uso de Benzodiazepínicos entre Idosos residentes na comunidade: prevalencia, impacto sobre a funçäo cognitiva e sobre o sono / Benzodiazepine tratment among elderly patients in the comunity: prevalence and impact in the cognitive function and sleep

OBJETIVOS: 1) Determinar a prevalencia do uso diario e continuo de benzoadiazepínicos entre idosos residentes na comunidade.2) Identificar o impacto deste uso sobre os padröes do sono e sobre a funçäo cognitiva.MATERIAL E METODOS: de