Characteristics of a Diverse Cohort of Stroke Patients with SARS-CoV-2 and Outcome by Sex.

BACKGROUND AND PURPOSE: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection is associated with stroke. The role of sex on stroke outcome has not been investigated. To objective of this paper is to describe the characteristics of a diverse cohort of acute stroke patients with COVID-19 disease and determine the role of sex on outcome. METHODS: This is a retrospective study of patients with acute stroke and SARS-CoV-2 infection admitted between March 15 to May 15, 2020 to one of the six participating comprehensive stroke centers. Baseline characteristics, stroke subtype, workup, treatment and outcome are presented as total number and percentage or median and interquartile range. Outcome at discharge was determined by the modified Rankin Scale Score (mRS). Variables and outcomes were compared for males and females using univariate and multivariate analysis. RESULTS: The study included 83 patients, 47% of which were Black, 28% Hispanics/Latinos, and 16% whites. Median age was 64 years. Approximately 89% had at least one preexisting vascular risk factor (VRF). The most common complications were respiratory failure (59%) and septic shock (34%). Compared with females, a higher proportion of males experienced severe SARS-CoV-2 symptoms requiring ICU hospitalization (73% vs. 49%; p = 0.04). When divided by stroke subtype, there were 77% ischemic, 19% intracerebral hemorrhage and 3% subarachnoid hemorrhage. The most common ischemic stroke etiologies were cryptogenic (39%) and cardioembolic (27%). Compared with females, males had higher mortality (38% vs. 13%; p = 0.02) and were less likely to be discharged home (12% vs. 33%; p = 0.04). After adjustment for age, race/ethnicity, and number of VRFs, mRS was higher in males than in females (OR = 1.47, 95% CI = 1.03-2.09). CONCLUSION: In this cohort of SARS-CoV-2 stroke patients, most had clinical evidence of coronavirus infection on admission and preexisting VRFs. Severe in-hospital complications and worse outcomes after ischemic strokes were higher in males, than females.

Evaluation of optical density of the midpalatal suture 3 months after surgically assisted rapid maxillary expansion.

OBJECTIVES: This study evaluated new bone formation at the midpalatal suture after surgically assisted rapid maxillary expansion (SARME) by optical density analysis. METHODS: The study population consisted of 18 patients, 10 males and 8 females. All patients presented maxillary atresia with posterior crossbite and were submitted to SARME. Maxillary occlusal radiographs were taken at three stages (before SARME, immediately after SARME and after 3 months). Three patients did not attend the session at the 3-month period for achievement of the occlusal radiography and thus were excluded, leading to a final sample of 15 patients. Two regions were selected and analysed at each stage. Region A measured 8 x 1 mm(2) and was located 1.2 cm from the tangent to the maxillary central incisors at the region of the midpalatal suture. Region B measured 5 x 9 mm(2) and was located 4.3 cm from the tangent to the maxillary central incisors at the region of the midpalatal suture. An aluminium scale (step wedge) with eight steps varying from 1 mm to 8 mm was adapted at the end of the films. Radiographs were taken on a Spectro 70X machine (Dabi Atlante, Ribeirão Preto, Brazil) set at 70 kVp and 10 mA with an exposure time of 1.0 s. Radiographs were scanned using a Power Look 1000 scanner (Umax, Taiwan, China) and a computer Dimension E510 (Dell Computer, Taiwan, China). Optical density analysis was performed after digitization of radiographs using the software Image Tool (UTHSCSA, San Antonio, TX). RESULTS: Statistical analysis of region A revealed statistically significant differences between Stages I and II (P=0.0001), Stages II and III (P=0.0001) and Stages I and III (P=0.0003). In region B, statistically significant differences were observed between Stages I and II, I and III and II and III (P=0.0018, P=0.0003 and P=0.0003, respectively). CONCLUSIONS: Optical density analysis improves post-treatment control of SARME procedures by surgeons and orthodontists. After 3 months, new bone formation at the midpalatal suture is not complete.

Low levels of ventricular CSF orexin/hypocretin in advanced PD.

The origins of excessive daytime sleepiness in Parkinson disease (PD) are unclear. The authors hypothesize that orexin neurons, a recently identified wake promoting system, could contribute to its pathophysiology. They measured orexin-A/hypocretin-1 concentration in ventricular CSF in 19 parkinsonian patients and compared it with neurologic controls. Orexin levels were lower in patients and decreased with the severity of the disease. The authors suggest that orexin neurons contribute to daytime sleepiness in late stage PD.

Graded microstructure and mechanical properties of human crown dentin.

The mineralized tissue of intertubular dentin is a collagen-mineral composite with considerable local variations of mechanical properties. Area scans of human coronal dentin were made by complementary methods to investigate correlations between local mechanical properties and the density, size, and crystallinity of the mineral particles. Scanning images from the same specimen were collected with Fourier-transform infrared microspectroscopy in reflectance mode (FTIR-RM), small angle X-ray scattering (SAXS), quantitative backscattered electron imaging (qBEI), and Nanoindentation in an atomic force microscope. The mineral content of dentin was found to decrease and the thickness of mineral crystals to increase towards the dentin-enamel junction (DEJ). Hardness and elastic modulus both decreased towards the DEJ. In a correlation analysis, the mineral content and, even more, the thickness of mineral crystals were found as the best predictors of hardness. The dentin layer close to the DEJ corresponds to a local minimum in hardness and elastic modulus, a configuration known to be an effective obstacle for crack propagation. Hence, the observed variations of mechanical and structural properties in an area between 0 and 1.5 mm below the DEJ define crown dentin as a gradient material optimized for its mechanical function.

Nasal obstruction as a risk factor for sleep apnoea syndrome.

Nasal obstruction has frequently been mentioned as a possible risk factor in obstructive sleep apnoea syndrome (OSAS). Over a 2-yr period, 541 unselected consecutive snorers referred for suspected breathing disorders during sleep were included to undergo posterior rhinomanometry. In addition cephalometric landmarks and body mass index (BMI) were obtained. Polysomnography was used to determine the number of abnormal respiratory events that occurred during sleep. OSAS was defined as 15 episodes, or more, of apnoea or hypopnoea per hour of sleep (AHI). Of the 541 consecutive snorers 528 underwent nasal resistance measurement by posterior rhinomanometry (failure rate: 2.4%). Patients with OSAS (259 patients) had higher nasal resistance than patients without OSAS (2.6+/-1.6 hPa x L x s(-1) versus 2.2+/-1.0 hPa x L x s(-1), respectively, p<0.005). A stepwise multiple regression analysis showed that BMI, male sex, nasal resistance, and cephalometric parameters were contributing factors to the AHI. The r2-value of the multiple regression analysis was 0.183. Nasal resistance contributed 2.3% of the variance (p<0.0001), whereas mandibular plane-hyoid distance, BMI, male sex and age contributed 6.2%, 4.6%, 3% and 1.3% of the variance, respectively. To conclude, daytime nasal obstruction is an independent risk factor for OSAS.

Predictive value of pulmonary function parameters for sleep apnea syndrome.

Nocturnal polysomnography is the standard diagnostic test for sleep apnea syndrome (SAS) but is both expensive and time-consuming. We developed a predictive index for SAS based on pulmonary function data, including respiratory resistance determined by the forced oscillation technique, from 168 obese snorers with suspected SAS. Our model used logistic regression to obtain case-by-case predictions of the probability of SAS, defined as an apnea-hypopnea index (AHI) > or = 15 during overnight polysomnography. We then tested our model in a prospective group of 101 similar patients. Specific respiratory conductance and daytime oxygen saturation contributed significantly to the model. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the index computed from these parameters were 98%, 86%, 90%, and 97%, respectively. In the prospective group, the model proved repeatable, with 100% sensitivity, 84% specificity, 86% PPV, and 100% NPV. The high NPV may help to identify obese snorers with a SAS risk that is so low as to make polysomnography unnecessary. Based on the 50% prevalence of SAS in our study and on the fact that polysomnography is required in all patients with daytime somnolence, we calculated that using our model would have obviated the need for polysomnography in 38% of our patients.

Constant vs. automatic continuous positive airway pressure therapy: home evaluation.

STUDY OBJECTIVES: To compare the efficacy and patient tolerance, compliance, and preference between auto-continuous positive airway pressure (CPAP) and constant CPAP. DESIGN: Single-blinded, crossover, cohort study of consecutive patients with obstructive sleep apnea syndrome, with two treatment periods of 2 months each. PATIENTS: Twenty-five patients (22 men, 3 women) with sleep apnea syndrome confirmed by ambulatory polysomnography. MEASUREMENTS AND INTERVENTIONS: After baseline polysomnography, patients underwent in-laboratory polysomnography for titration of constant CPAP. The order of treatment was randomly allocated, either auto-CPAP and then constant CPAP, or vice versa. The auto-CPAP pressure range was 6 to 16 cm H(2)O. At the end of each 2-month period, patients underwent a control ambulatory polysomnography and received a questionnaire on subjective well-being and device evaluation. Duration of use was checked through CPAP device monitoring. RESULTS: No differences were found in apnea/hypopnea index (constant CPAP, 9.7+/-1.9 events/h vs auto-CPAP, 10.6+/-9.3 events/h), awakening/arousal index (constant CPAP, 13.7 +/- 8.0 events/h vs auto-CPAP, 15.5 +/- 8.9 events/h), slow-wave sleep duration, nocturnal saturation, or complaint of daytime sleepiness. The mean pressure required was significantly lower during auto-CPAP than during constant CPAP (8.8+/-1.8 cm H(2)O vs. 9.7+/-2.6 cm H(2)O, respectively). Patient tolerance, compliance, and duration of use were similar with both treatments. CONCLUSIONS: Auto-CPAP is as effective as constant CPAP. A wide pressure range for auto-CPAP can be used in all patients, suggesting that, in the future, use of a broad pressure range in the auto-CPAP mode could obviate the need for the titration night.

[Sleep apnea syndrome and stroke in the elderly population]. / Syndrome d'apnées du sommeil et accident vasculaire cérébral dans une population âgée.

The objective was to compare the prevalence of sleep apnea syndrome (SAS) in elderly individuals with a history of stroke to the one in individuals, matched by age and sex with a history of insomnia. To determine if previous subjective sleep complaints in the elderly are associated with stroke. A cross-sectional study with subsequent 3-year follow-up was designed in an acute geriatric inpatient unit. 19 subjects with documented stroke and 21 subjects with insomnia were included. All participants were assessed with a sleep questionnaire, an overnight polysomnographic examination including a recording of respiratory movements, and pulse oximetry. SAS was diagnosed in 68.4 p. 100 in the stroke group compared with 28.6 p. 100 in the insomnia group (p = 0.01). The median apnea/hypopnea index was significantly higher in the stroke group: 25 events per hour versus 2 in the insomnia group (p = 0.01). The median lowest oxygen saturation was not significantly different in the two groups (p = 0.3). Snoring and previous daytime sleepiness were both correlated with stroke (p = 0.05, p = 0.003). Among sleep complaints and cardiovascular risk factors, only a history of diabetes and previous daytime sleepiness were found to be significantly associated with stroke (p = 0.01, p = 0.002). Mortality was higher in SAS subjects (58.8 p. 100) than in non SAS subjects (33 p. 100). The difference was not statistically significant (p = 0.14), but a tendency could be noticed. SAS is a common finding in elderly individuals after a stroke. Physicians must be aware of the risks of prescribing sedatives and anxiolytics to these patients.

Respiratory resistive impedance as an index of airway obstruction during nasal continuous positive airway pressure titration.

Esophageal pressure amplitude (DeltaPes), inspiratory pulmonary resistance (RLI) and inspiratory flow limitation score (FS) are used as indices of upper airway obstruction for the titration of nasal continuous positive airway pressure (nCPAP) in patients with obstructive sleep apnea syndrome (OSAS). This study was designed to determine whether oscillatory respiratory resistive impedance at 16 Hz (RFO) might be proposed as an alternative index. Eleven OSAS patients were studied during a night of polysomnography-controlled nCPAP titration. Nasal flow (V) and airway opening and esophageal pressures (Pao and Pes, respectively) were continuously measured during nasal breathing, and forced-flow oscillations (FO) were applied for 5 min at each nCPAP level. RLI was calculated by linear regression analysis of resistive pressure versus V over inspiration. R FO was obtained by linear regression analysis of respiratory resistive impedance versus frequency. Application of FO affected neither sleep nor pulmonary mechanics. RFO correlated with RLI in all patients. RFO did not correlate with DeltaPes in two patients, and was not significantly related to FS in five patients. This study demonstrates the applicability of the FO technique in sleeping patients receiving nCPAP, and the reliability of RFO for assessing pulmonary resistance. RFO might therefore be proposed as a quantitative index of airway obstruction for nCPAP titration.

Heavy snoring with upper airway resistance syndrome may induce intrinsic positive end-expiratory pressure.

We studied eight heavy snorers with upper airway resistance syndrome to investigate potential effects of sleep on expiratory airway and lung resistance, intrinsic positive end-expiratory pressure, hyperinflation, and elastic inspiratory work of breathing (WOB). Wakefulness and non-rapid-eye-movement sleep with high- and with low-resistance inspiratory effort (H-RIE and L-RIE, respectively) were compared. No differences in breathing pattern were seen across the three conditions. In contrast, we found increases in expiratory airway and lung resistance during H-RIE compared with L-RIE and wakefulness (56 +/- 24, 16 +/- 4, and 11 +/- 4 cmH2O . 1(-1) . s, respectively), with attendant increases in intrinsic positive end-expiratory pressure (5.4 +/- 1.8, 1.4 +/- 0.5, and 1.3 +/- 1.3 cmH2O, respectively) and elastic WOB (6.1 +/- 2.2, 3.7 +/- 1.2, and 3.4 +/- 0.7 J/min, respectively). The increase in WOB during H-RIE is partly caused by the effects of dynamic pulmonary hyperinflation produced by the increased expiratory resistance. Contrary to the Starling model, a multiple-element compliance model that takes into account the heterogeneity of the pharynx may explain flow limitation during expiration.

Arterial blood pressure response to transient arousals from NREM sleep in nonapneic snorers with sleep fragmentation.

STUDY OBJECTIVES: To assess the hemodynamic effects of graded arousals during nonrapid eye movement (NREM) sleep in patients with partial upper airway obstruction during sleep without obstructive sleep apnea/hypopnea, overnight beat-to-beat BP was recorded in six patients. SETTING: At the end of each nonapneic obstructive event, EEG responses were graded as follows: grade 2, grade 1, and grade 0 were defined as increased high-frequency EEG lasting >15 s, 3 to 15 s, and no EEG arousals according to the American Sleep Disorders Association, respectively. MEASUREMENTS AND RESULTS: The following were observed during grade 0, 1, and 2 EEG patterns (mean+/-SD): systolic pressure increased by 7.1+/-1.5, 11.7+/-1.9, and 14.2+/-3.4 (p<0.005), respectively; diastolic pressure increased by 4.6+/-0.6, 6.7+/-1.7, and 9.4+/-3.0 (p<0.005), respectively; heart rate increased by 2.9+/-0.4, 3.9+/-2.2, and 8.6+/-4.6 (p<0.005), respectively. CONCLUSIONS: We conclude that nonapneic-nonhypopneic obstructive events are followed by arterial systemic pressure increases whose magnitude varies with the grade of the arousal.

Pulmonary function in obese snorers with or without sleep apnea syndrome.

We evaluated pulmonary function abnormalities associated with the sleep apnea syndrome (SAS) in 170 habitual snorers without SAS (n = 62, apnea-hypopnea index [AHI] < 10 per hour of sleep), with moderately severe SAS (n = 56, 10 < or = AHI < 30) or with severe SAS (n = 52, AHI > or = 30). The three groups were similar regarding obesity (BMI approximately 30 kg.m-2) and smoking history (approximately 20 pack-years). Pulmonary function was assessed by spirometry, forced oscillation mechanics, and gas exchange studies. Forced expiratory flows decreased as the SAS severity increased (p < 0.001, p < 0.02, and p < 0.05 for FEF50, FEV1, and FEV1/VC, respectively). Multiple regression analysis showed that the correlation between FEV50 and the AHI persisted when smoking history was taken into account (p < 0.05), suggesting that SAS may be an independent risk factor for small airway disease. A highly significant correlation was found between specific respiratory conductance (sGrs) and the AHI (p < 0.0001). In a multiple regression analysis (p < 0.0001), variables that influenced sGrs were distal airway obstruction as assessed by FEV50 (p < 0.05), morphological upper airway abnormalities as assessed by cephalometric parameters (p < 0.02), and the AHI (p < 0.0005). SAS appears to be highly correlated to lower and upper airway obstruction, as demonstrated by a reduction in specific respiratory conductance, which adds to the increase in breathing load due to obesity.

Sleep apnea-like syndrome induced by nitrous oxide inhalation in normal men.

To study the relationship between sedation and respiration under N2O, we performed polysomnographic recordings in 15 healthy men with documented normal breathing patterns during sleep. In a first study in five subjects, we found that 50% N2O in O2 compared to 50% O2 increased sleep latency to stage 2 (59 +/- 12 vs. 17 +/- 3 min), total sleep duration (59 +/- 12 vs. 26 +/- 11 min), depth of sleep and respiratory events during sleep (18 +/- 5 vs. 1 +/- 1/h of sleep). In a second study, ten subjects were exposed to N2O (30 and 50%) in O2 during two consecutive experimental periods. Eight subjects had EEG features of physiological sleep, but nevertheless exhibited a total of 181 respiratory events. Respiratory disturbance index (RDI) during sleep was similar under 30 and 50% N2O (25 +/- 7 and 25 +/- 5/h of sleep, respectively). Obstructive events predominated, except in three subjects during N2O 30% and one during N2O 50% exposure. We conclude that N2O can induce central and obstructive sleep apneas.

Effect of zopiclone on sleep, night-time ventilation, and daytime vigilance in upper airway resistance syndrome.

We have assessed the effects of zopiclone (7.5 mg), a new cyclopyrrolone hypnotic drug, on ventilation, sleep parameters, and daytime vigilance in snorers with upper airway resistance syndrome (UARS). Using a randomized double-blind design, eight male patients with UARS took either oral zopiclone or a placebo each evening for seven consecutive days and then crossed over to the other drug after a 7 day placebo period. Polysomnography followed by a multiple sleep latency test (MSLT) was performed during the last night of each treatment period. Zopiclone produced significant improvements in the sleep efficiency index (total sleep time/time in bed) (placebo 84+/-15% versus zopiclone 91+/-7%) and average MSLT (placebo 10.3+/-3.7 min versus zopiclone 14.9+/-2.8 min), as well as nonsignificant improvements in sleep onset latency and total sleep time. It had no effect on sleep architecture or on the arousal index (placebo 17+/-8 arousals x h(-1) versus zopiclone 17+/-4 arousals x h[-1]). Furthermore, none of the respiratory parameters were significantly affected by zopiclone. In conclusion, zopiclone has no adverse effects on sleep architecture, respiratory parameters during sleep, and daytime sleepiness in patients with UARS.

Evaluation of an auto-nCPAP device based on snoring detection.

We evaluated an auto-nasal continuous positive airway pressure (nCPAP) prototype (MC+; SEFAM, Nancy, France) in which apnoea/hypopnoea detection was disabled and nasal mask pressure vibration detection was the only mode of pressure setting. The device was tested in 15 previously untreated obstructive sleep apnoea patients during a night with polysomnography. We observed that a single night of auto-nCPAP improved the apnoea/hypnoea index (AHI) (12 +/- 21 vs 51 +/- 31 disordered breathing events.h-1 of sleep (mean +/- SD)), the awakening-arousal index (13 +/- 20 vs 40 +/- 26 arousals.h-1 of sleep), and duration of slow wave sleep (102 +/- 49 vs 71 +/- 56 min) but not of rapid eye movement (REM) sleep (55 +/- 31 vs 64 +/- 38 min). Auto-nCPAP was effective (apnoea/hypopnoea and arousal indices < 10 events.h-1) in all but three patients. Auto-nCPAP was ineffective in one patient, whose obstructive respiratory events were not preceded by nasal mask pressure vibration detection, and in two patients who were quasi-permanent mouth breathers. Snoring detection may be effective in sleep apnoea syndrome with heavy snoring and without permanent mouth breathing, during the first night of nasal continuous positive airway pressure treatment.

Effect of zolpidem on sleep and ventilatory patterns at simulated altitude of 4,000 meters.

The purpose of this study was to assess the effect of zolpidem 1 0 mg, a new imidazopyridine hypnotic drug, on sleep and respiratory patterns at a simulated altitude of 4,000 meters. Eight male subjects spent three nights in a decompression chamber. The first study night was spent at the ambient pressure corresponding to sea level. The two other nights were spent at a simulated altitude of 4,000 meters with either zolpidem or a placebo in random order according to a double-blind, crossover design. All subjects showed periodic breathing (PB) during sleep at simulated high altitude. Furthermore, altitude was associated with decreases in total sleep time (TST), slow-wave sleep (SWS), and REM sleep, and with significant increases in Stage 1 duration and in the arousal index. Most arousals were synchronous with the hyperpneic phase of PB. The main finding of our study is that zolpidem improved sleep characteristics at high altitude, inducing a decrease in sleep onset latency (placebo, 22 +/- 12 min versus zolpidem, 10 +/- 6 min), an increase in SWS duration (placebo, 46 +/- 28 min versus zolpidem, 69 +/- 28 min), and a reduction in the arousal index during SWS (placebo, 7.4 +/- 4.1 per h versus zolpidem: 2.4 +/- 1.0 per h). Furthermore, none of the respiratory parameters were significantly affected by zolpidem in any sleep stage. In conclusion, zolpidem improved sleep quality at high altitude without adversely affecting respiration.

Sleep fragmentation as a risk factor for hypertension in middle-aged nonapneic snorers.

Although a high prevalence of hypertension has been observed in snorers, whether there is a direct link between hypertension and snoring remains controversial. It has recently been demonstrated that an abnormal amount of breathing effort during snoring is responsible for sleep fragmentation even in the absence of sleep apnea syndrome criteria. We hypothesized that sleep fragmentation during snoring may be a direct risk factor for the development of hypertension. On the basis of polysomnographic data, 105 nonapneic patients between 40 and 65 years of age referred for snoring with social impairment were selected and categorized as snorers with (n=55) or without sleep fragmentation (n=50) based on whether the arousals index was 10 or greater or less than 10/h of sleep, respectively. Sleep distribution did not differ between the two groups, except for a longer duration of wake after sleep onset (58 +/- 43 min vs 42 +/- 38 min) and a shorter duration of slow-wave sleep in the group with sleep fragmentation (72 +/- 34 min vs 97 +/- 34 min). Although there were no statistically significant differences between the snorers with and without sleep disruption in terms of age (51.3 +/- 7.7 vs 48.6 +/- 6.0 years), body mass index (26.9 +/- 4.0 vs 27.2 +/- 5.5 kg/m2), sex ratio, respiratory indexes during sleep, daytime sleepiness, and daytime tiredness, prevalence of systemic hypertension was significantly higher in the sleep-fragmented group (20/55 vs 7/50). This significant difference persisted (16/51 vs 6/49) when patients using antihypertensive drugs with possible effects on the CNS were excluded. Our data suggest that sleep fragmentation is common in patients who seek medical help for snoring with social impairment and may play a role in the development of hypertension.

Modafinil: a double-blind multicentric study.

Modafinil is a central putative alpha-1 postsynaptic agonist with vigilance-promoting properties. Fifty narcoleptics (33 male and 17 female) participated in a multicentric study aimed at assessing the effects of the compound on night sleep, feeling on awakening, excessive daytime sleepiness and cataplexy. Modafinil was administered in a double-blind cross-over design at a daily dosage of 300 mg versus placebo. The duration of the study was 12 weeks, including a 2-week "run in" period with placebo, a first 4-week treatment period with either modafinil or placebo, a 2-week wash-out period with placebo and a second 4-week treatment period with either placebo or modafinil. Daily evaluation was based on a sleep log, visual analog scales, a sleep questionnaire and a clinical global index. Sleep laboratory evaluation took place on nights 1, 28, 42 and 70. It included 1 night of polysomnography preceded by a questionnaire on therapeutic and side effects, and a maintenance of wakefulness test (MWT). Sleep logs did not show any modification of night sleep, but a reduction of daytime sleepiness and sleep. Feeling on awakening was not modified. An overall benefit was noted by physicians as well as by patients. MWT disclosed a positive effect of modafinil on excessive daytime sleepiness. Cataplexy was not modified.

Prevalence of sleep-disordered breathing in patients on a heart transplant waiting list.

We investigated the prevalence of sleep-disordered breathing in 20 outpatients on a heart transplant waiting list. All were younger than 60 years and had severe stable cardiac failure with a cardiac index below 2.5 L/min/m2 and a left ventricular ejection fraction below 25%. Nine patients (45%) exhibited ten or more apneas and hypopneas per hour of sleep (apneic group). In all patients but one, apneas and hypopneas were predominantly of the central type and occurred during Cheyne-Stokes respiration. There were no statistically significant differences between the apneic and nonapneic groups of patients in terms of age (51 +/- 5 years vs 49 +/- 11), body mass index (24 +/- 4 kg/m2 vs 22 +/- 3), cardiac index (1.87 +/- 0.35 L/min/m2 vs 1.84 +/- 0.40), isotopic left ventricular ejection fraction (13 +/- 5 vs 12 +/- 3%), arterial blood gas, or pulmonary function tests. Hypnogram characteristics showed poorer sleep quality in the apneic group than in the nonapneic group, with a larger number of arousals; this difference was found both for arousals lasting more than 30 s (8 +/- 5/h vs 4 +/- 2) and for arousals lasting less than 30 s (18 +/- 16/h vs 5 +/- 6) and was associated with increased wakefulness after sleep onset in the apneic group (138 +/- 82 min vs 84 +/- 45). Arousals were strongly associated with hyperpneic phases of Cheyne-Stokes respiration. We conclude that sleep-disordered breathing is common in patients with end-stage heart disease and adversely affects the quality of sleep.