Central sleep apnoea syndrome in patients with chronic heart disease: a critical review of the current literature

The Role of Sleep in Cardiovascular Disease

PURPOSE OF REVIEW

Sleep is an important component of cardiovascular (CV) health. This review summarizes the complex relationship between sleep and CV disease (CVD). Additionally, we describe the data supporting the treatment of sleep disturbances in preventing and treating CVD.

RECENT FINDINGS

Recent guidelines recommend screening for obstructive sleep apnea in patients with atrial fibrillation. New data continues to demonstrate the importance of sleep quality and duration for CV health. There is a complex bidirectional relationship between sleep health and CVD. Sleep disturbances have systemic effects that contribute to the development of CVD, including hypertension, coronary artery disease, heart failure, and arrhythmias. Additionally, CVD contributes to the development of sleep disturbances. However, more data are needed to support the role of screening for and treatment of sleep disorders for the prevention of CVD.

A State-of-the-Art Review on Sleep Apnea Syndrome and Heart Failure

Heart failure (HF) affects many patients worldwide every year. It represents a leading cause of hospitalization and still, today, mortality remains high, albeit the progress in treatment strategies. Several factors contribute to the development and progression of HF. Among these, sleep apnea syndrome represents a common but still underestimated factor because its prevalence is substantially higher in patients with HF than in the general population and is related to a worse prognosis. This review summarizes the current knowledge about sleep apnea syndrome coexisting with HF in terms of morbidity and mortality to provide actual and future perspectives about the diagnosis, evaluation, and treatment of this association.

Effect of home non-invasive ventilation on left ventricular function and quality of life in patients with heart failure and central sleep apnea syndrome

Central Sleep Apnea Syndrome (CSAS) and Cheyne-Stokes breathing are prevalent in patients with heart failure with reduced ejection fraction (HFrEF). Positive respiratory pressure therapy (PAP) associated with drug therapy for heart failure can improve quality of life, although tolerance to PAP therapy can be difficult to achieve. Materials and method: Patients for this prospective, mono-center, cohort study were selected from patients with chronic heart failure who present at the Sleep Laboratory of the Medical Clinic of Pneumology, Oradea who underwent polysomnography. 38 HFrEF and CSAS patients were included between January 2019 to December 2021 in the study, with an apnea-hypopnea index (AHI) >=15/hour of sleep. Echocardiographic hemodynamic parameters (left ventricular ejection fraction-LVEF, mitral regurgitation score), PAP compliance, and quality of life using the severe respiratory failure questionnaire (SRI) at the initiation of PAP and after 3 months were included. Results: After 3 months of PAP therapy LVEF increased significantly (from 31.4% ±12.2to 38.0%±10.9, p=0.0181), AHI decreased (from 40.1±18.7 to 6.8±6.1 events/h, p<0.0001) and all the categories of SRI showed improvement with significant general score increase (from 57.0±15.1 to 66.6±16.9, p<0.0001). Conclusion: The association of PAP therapy with drug therapy in patients with HFrEF and CSAS improves hemodynamic parameters and quality of life. Keywords: Chronic heart failure, positive airway pressure therapy, central sleep apnea syndrome

Cheyne-stokes respiration in children with heart failure

Cheyne-Stokes respiration (CSA-CSR) is a form of central sleep apnea characterized by alternating periods of hyperventilation and central apneas or hypopneas. CSA-CSR develops following a cardiac insult resulting in a compensatory increase in sympathetic activity, which in susceptible patients causes hyperventilation and destabilizes respiratory control. The physiological changes that occur in CSA-CSR include hyperventilation, a reduced blood gas buffering capacity, and circulatory delay. In adults, 25% to 50% of patients with heart failure are reported to have CSA-CSR. The development of CSA-CSR in this group of patients is considered a poor prognostic sign. The prevalence, progression, and treatment outcomes of CSA-CSR in children remain unclear with only 11 children being described in the literature. The lack of data is possibly not due to the paucity of children with severe heart failure and CSA-CSR but because they may be under-recognized, compounded by the absence of routine polysomnographic assessment of children with moderate to severe heart failure. Building on much broader experience in the diagnosis and management of CSA-CSR in adult sleep medicine and our limited experience in a pediatric quaternary center, this paper will discuss the prevalence of CSA-CSR, its' treatment options, outcomes in children, and the potential future direction for research in this understudied area of pediatric sleep medicine.

Use of the Functional Evaluation of Cardiac Health questionnaire to assess health-related quality of life before and after mitral valve repair in dogs with myxomatous mitral valve disease

OBJECTIVE

To determine changes in health-related quality of life up to 12 months after surgery in dogs with myxomatous mitral valve disease that undergo mitral valve repair.

ANIMALS

54 dogs that underwent mitral valve repair at a United Kingdom referral hospital.

PROCEDURES

Health-related quality of life was assessed with a previously validated, owner-completed questionnaire before and 1, 3, 6, and 12 months after surgery.

Results

There was a significant decrease in total score (corresponding to reduced negative impact of cardiac disease on quality of life) between the preoperative timepoint and all postoperative timepoints. A significant decrease in total score was also demonstrated between the 1- and 3-month timepoints, but no additional significant changes in total score between adjacent timepoints were identified beyond 3 months after surgery. Significant improvements in individual question scores were found up to 12 months after surgery.

CLINICAL RELEVANCE

Health-related quality of life was significantly improved following mitral valve repair in dogs with myxomatous mitral valve disease and this improvement persisted for up to a year after surgery. These results may be useful when counseling owners of dogs considered candidates for this procedure.

Serious Adverse Events after a Single Shot of Intrathecal Morphine: A Case Series and Systematic Review

Background

The dose of intrathecal morphine is important because of its narrow therapeutic range. Due to a compounding error, pharmacy-compounded, ready-to-use syringes contained 1 mg ml⁻¹ morphine instead of the intended 50 mcg ml⁻¹. Six patients consequently received this twenty-fold dose. This study aims to describe the serious adverse events in these six patients and a systematic review is added to describe the characteristics of serious adverse events after intrathecal morphine.

Methods

A retrospective case series described all six patients that received the erroneous morphine intrathecally for analgesia after laparoscopic segmental colonic resections. The patients' charts were reviewed for the occurrence, timing, duration and management of adverse events, the vital signs at the night after surgery, and length of hospital stay. A systematic review investigated characteristics of serious adverse events after intrathecal morphine in a perioperative setting.

Results

Four patients had a serious adverse event, which was respiratory depression combined with somnolence (n = 3) and hypotension (n = 1). The review yielded 63 cases with serious adverse events, predominantly somnolence and/or respiratory depression. The onset occurred between 2 and 24 hours after injection. The severity of symptoms varied and life-threatening respiratory depression only occurred after a dose >900 mcg or when potentiating medication was used. Naloxone did not affect analgesia. No prolonged sequalae occurred.

Conclusion

This study reveals that respiratory depression and somnolence are the predominant serious adverse events after intrathecal morphine in a perioperative setting and demonstrated a large variation in the presentation of symptoms.

Effect of mild obstructive sleep apnea in mountaineers during the climb to Mount Aconcagua

OBJECTIVE

to compare mountaineers with and without asymptomatic sleep apnea (OSA) before the ascent and to study high altitude-related sleep disorders, its interaction with metabolic, neuroendocrine and immunological components.

MATERIAL AND METHODS

During an expedition to Mount Aconcagua, researchers assessed the respiratory polygraphy (RP), clinical condition and inflammatory parameters, and rhythm of cortisol secretion in mountaineers sleeping at different altitude camps.

RESULTS

8 athletes (4 women), 36 years old (25-51) participated. Baseline and final BMI were; 23.6 (20.9-28.7) and 22.77 (20.9-27.7), respectively: p<0.01. 40 valid RP recordings were analyzed. At 746 m.a.s.l. (baseline), only 2 mountaineers presented mild asymptomatic OSA. The OSA group presented baseline apnea-hypopnea index (AHI) values between 5-15 events per hour, which evidence a mild respiratory sleep disorder with AHI increased by altitude depending of central apneas and hypopneas (p<0.05) as high altitude periodic breathing pattern but no increase in obstructive apneas (p<0.01). The circadian rhythm of cortisol was maintained in all cases in which they had not received treatment with dexamethasone and their values increased with the altitude reached. Increased systolic blood pressure was observed in the OSA group.

CONCLUSION

In a context of hypobaric hypoxia, individuals with pre-existing asymptomatic OSA are prone to experiencing lower oxygen saturations and clinical deterioration.

Hospice Use Among Patients with Heart Failure

Despite its many benefits, hospice care is underused for patients with heart failure. This paper discusses the factors contributing to this underuse and offers recommendations to optimise use for patients with heart failure and proposes metrics to optimise quality of hospice care for this patient group.

Symptom burden in heart failure: assessment, impact on outcomes, and management

Evidence-based management has improved long-term survival in patients with heart failure (HF). However, an unintended consequence of increased longevity is that patients with HF are exposed to a greater symptom burden over time. In addition to classic symptoms such as dyspnea and edema, patients with HF frequently suffer additional symptoms such as pain, depression, gastrointestinal distress, and fatigue. In addition to obvious effects on quality of life, untreated symptoms increase clinical events including emergency department visits, hospitalizations, and long-term mortality in a dose-dependent fashion. Symptom management in patients with HF consists of two key components: comprehensive symptom assessment and sufficient knowledge of available approaches to alleviate the symptoms. Successful treatment addresses not just the physical but also the emotional, social, and spiritual aspects of suffering. Despite a lack of formal experience during cardiovascular training, symptom management in HF can be learned and implemented effectively by cardiology providers. Co-management with palliative medicine specialists can add significant value across the spectrum and throughout the course of HF.

Sleep Disturbances in Patients with Chronic Heart Failure and Their Holistic Consequences—What Different Care Actions can be Implemented?

Background: Sleep disturbances are prevalent among elderly, especially among those with chronic heart failure (CHF) and can affect all dimensions of quality of life (QOL) negatively.

Aim: To describe the most common causes leading to sleep disturbances in patients with CHF, their consequences from a holistic perspective and different care actions that can be implemented.

Methods: MEDLINE and CINAHL databases were searched from 1989 to July 2004.

Findings: Sleep disordered breathing (SDB), and insomnia were the most common causes for sleep disturbances and occurs in 45–82% (SDB) and one-third (insomnia) of all patients with CHF. SDB cause a disturbed sleep structure with frequent awakenings, as well as several adverse effects on the cardiovascular system causing increased morbidity and mortality. Insomnia, caused by anxiety, an unknown life situation in relation to the debut of CHF, or symptoms/deteriorations of CHF can lead to negative effects on all aspects of QOL, as well as daytime sleepiness.

Conclusion: The high prevalence of sleep disturbances and their holistic consequences should be taken into account when nurses asses and plan the care for patients with CHF. Randomized studies with large sample sizes evaluating non-pharmacological nursing interventions that improve sleep are needed.

Heart failure and sleep disorders

Awareness of the importance of sleep-related disorders in patients with cardiovascular diseases is growing. In particular, sleep-disordered breathing, short sleep time, and low sleep quality are frequently reported by patients with heart failure (HF). Sleep-disordered breathing, which includes obstructive sleep apnoea (OSA) and central sleep apnoea (CSA), is common in patients with HF and has been suggested to increase the morbidity and mortality in these patients. Both OSA and CSA are associated with increased sympathetic activation, vagal withdrawal, altered haemodynamic loading conditions, and hypoxaemia. Moreover, OSA is strongly associated with arterial hypertension, the most common risk factor for cardiac hypertrophy and failure. Intrathoracic pressure changes are also associated with OSA, contributing to haemodynamic alterations and potentially affecting overexpression of genes involved in ventricular remodelling. HF treatment can decrease the severity of both OSA and CSA. Indeed, furosemide and spironolactone administration, exercise training, cardiac resynchronization therapy, and eventually heart transplantation have shown a positive effect on OSA and CSA in patients with HF. At present, whether CSA should be treated and, if so, which is the optimal therapy is still debated. By contrast, more evidence is available on the beneficial effects of OSA treatment in patients with HF.

Prevalence and associations of respiratory-related leg movements: the MrOS sleep study

OBJECTIVES

Obstructive respiratory events often terminate with an associated respiratory-related leg movement (RRLM). Such leg movements are not scored as periodic leg movements (periodic limb movements during sleep, PLMS), although the criteria for distinguishing RRLM from PLMS differ between the American Academy of Sleep Medicine (AASM) and the World Association of Sleep Medicine (WASM)/ International Restless Legs Syndrome Study Group (IRLSSG) scoring manuals. Such LMs may be clinically significant in patients with obstructive sleep apnea (OSA). The prevalence and correlation of RRLM in men with OSA were examined.

METHODS

A case-control sample of 575 men was selected from all men with an apnea-hypopnea index (AHI, ≥3% desaturation criteria) ≥ 10 and good data from piezoelectric leg movement sensors at the first in-home sleep study in the MrOS cohort (mean age = 76.8 years). Sleep studies were rescored for RRLMs using five different RRLM definitions varying in both latency of leg movement onset from respiratory event termination and duration of the leg movement. The quartile of RRLM% (the number of RRLM/the number of hypopneas + apneas) was derived.

RESULTS

The nonparametric densities of RRLM% were most influenced by alterations in the latency rather than the duration of the LM. The most liberal RRLM definition (latency 0-5 s, duration 0.5-10 s) led to a median RRLM% of 23.4 (interquartile range 12.41, 37.12) in this sample. The average AHI and arousal index increased as the quartile of RRLM% increased, as well as the prevalence of chronic obstructive pulmonary disease (COPD). The prevalence of those with a history of hypertension decreased as RRLM% increased. The non-Caucasian race was associated with lower RRLM%.

CONCLUSION

Within an elderly sample with moderate to severe OSA, piezoelectric-defined RRLM% is associated with a number of sleep-related and demographic factors. Further study of the optimal definition, predictors, and consequences of RRLM is warranted.

Autonomic dysfunction in acute ischemic stroke: an underexplored therapeutic area?

Impaired autonomic function, characterized by a predominance of sympathetic activity, is common in patients with acute ischemic stroke. This review describes methods to measure autonomic dysfunction in stroke patients. It summarizes a potential relationship between ischemic stroke-associated autonomic dysfunction and factors that have been associated with worse outcome, including cardiac complications, blood pressure variability changes, hyperglycemia, immune depression, sleep disordered breathing, thrombotic effects, and malignant edema. Involvement of the insular cortex has been suspected to play an important role in causing sympathovagal imbalance, but its exact role and that of other brain regions remain unclear. Although sympathetic overactivity in patients with ischemic stroke appears to be a negative prognostic factor, it remains to be seen whether therapeutic strategies that reduce sympathetic activity or increase parasympathetic activity might improve outcome.

Differential timing of arousals in obstructive and central sleep apnea in patients with heart failure

STUDY OBJECTIVES

In obstructive sleep apnea (OSA), arousals generally occur at apnea termination and help restore airflow. However, timing of arousals in central sleep apnea (CSA) has not been objectively quantified, and since arousals can persist even when CSA is alleviated, may not play the same defensive role as they do in OSA. We hypothesized that arousals following central events would occur longer after event termination than following obstructive events and would be related to circulation time.

METHODS

We examined polysomnograms from 20 patients with heart failure (HF) (left ventricular ejection fraction ≤ 45%): 10 with OSA and 10 with CSA (apneahypopnea index ≥ 15). Twenty central or obstructive apneas or hypopneas were analyzed in each patient.

RESULTS

Compared to the OSA group in whom arousals generally occurred at obstructive event termination, in the CSA group they occurred longer after central event termination (0.9 ± 1.1 versus 8.0 ± 4.1 s, p < 0.0001), but before peak hyperpnea. Time from arousal to peak hyperpnea did not differ between groups (4.3 ± 1.1 vs 4.8 ± 1.6 s, p = 0.416). Unlike the OSA group, latency from apnea termination to arousal correlated with circulation time in the CSA group (r = 0.793, p = 0.006).

CONCLUSIONS

In HF patients with CSA, apnea-to-arousal latency is longer than in those with OSA, and arousals usually follow resumption of airflow. These observations provide evidence that arousals are less likely to act as a protective mechanism to facilitate resumption of airflow following apneas in CSA than in OSA.

Snoring and risk for obstructive sleep apnea among nigerians with heart failure: Prevalence and clinical correlates

Background:

Heart failure is an important cause of morbidity and mortality in developing nations like Nigeria. Sleep apnea and snoring has recently been recognized to be a cardiovascular risk factor. Sleep apnea is yet to be well studied among Africans with heart failure. We aimed to determine the prevalence of snoring and high risk for obstructive sleep apnea among Nigerians with stable heart failure.

Materials and Methods:

We studied 103 subjects that included 62 patients with heart failure and 41 control subjects. Demographic parameters and clinical examination were performed on the participants. The Berlin score and the Epworth Sleepiness Scale were administered for each participant. Echocardiography was done on all participants. Statistical analysis was done using Statistical Package for Social Sciences (SPSS) 17.0.

Results:

Snoring was reported in 48.4% of subjects with heart failure compared to 22.0% of control subjects ( P < 0.005). High risk for obstructive sleep apnea using the Berlin score was documented in 51.6% of heart failure subjects compared to 7.31% of controls. Excessive daytime somnolence occurred more in heart failure patients (51.6% vs. 9.8%, P < 0.05). Snorers tended to be older and were more likely to be obese than nonsnorers. Systolic blood pressure and fasting blood sugar were significantly higher among heart failure subjects with snoring than those without snoring (131.9 ± 19.2 vs. 119.2 ± 15.7 and 6.0 ± 0.8 vs. 5.4 ± 2.7, P < 0.005).

Conclusion:

Heart failure seems to be associated with snoring and a high risk for obstructive sleep apnea among Africans with heart failure. Assessment for sleep disordered breathing should be incorporated into their routine clinical workup.

Nocturnal peak in atrial tachyarrhythmia occurrence as a function of arrhythmia burden

INTRODUCTION

We examined circadian periodicity of atrial tachyarrhythmias (AT/AF) in a large group of patients with implantable devices, which allow continuous collection of the event data over prolonged periods of time.

METHODS AND RESULTS

A total of 16,130 AT/AF events were recorded in 236 patients (age: 63 ± 12 years, 27% female, 90% had a history of cardiovascular disease, 33% ischemic, LVEF: 49 ± 18%) over a period of 12 months. To exclude interactions with therapy, the patterns of arrhythmia occurrence were examined for all events and for those episodes that were preceded by at least 1, 6, and 24 hours of sinus rhythm. To prevent biasing toward patients with more frequent episodes, the patterns of AT/AF onset were analyzed both in absolute and patient-normalized (i.e., divided by the total number of events in each patient) units per hour per patient and then summarized for the entire group. In patients with <4 AT/AF events, the onset times were randomly distributed over 24-hour period. However, as the number of AT/AF events increased, a nocturnal pattern of occurrence (determined by the occurrence of a trough around noon) gradually emerged and became highly statistically significant (P < 10(-4) ). The magnitude of nocturnal peak of AT/AF events was well explained by a single-exponential function (R(2) = 0.97, P < 10(-2) ).

CONCLUSION

Patients with more frequent atrial tachyarrhythmias are more likely to develop AT/AF at night. Knowledge of patient-specific circadian patterns of arrhythmia occurrence can be useful for personalized management of individuals with significant arrhythmia burden.

Correlations of physiological activities in nocturnal Cheyne-Stokes respiration

We have conducted a power-spectrum-density (PSD) analysis of the distinct sleep stages of a previously diagnosed nocturnal Cheyne-Stokes respiration patient (NCSR) and studied the correlations of different physiological activities. This is the first study where the correlations were analyzed separately for different sleep stages and the influence of arousals was completely eliminated. Mathematical analysis of the polysomnographical records revealed clear indicators of the disorder in the form of large peaks in a very-low frequency range of f ≈ 0.02 Hz. We have shown existence of the significant entrainment of the cerebral and cardiac activities with respiration during different stages of sleep in the patient. The entrainment is highly pronounced in light (stage 2) and deep (stage 3) sleep, but is significantly less pronounced in rapid eye movement sleep. A correlation functions analysis revealed that the correlations between the central activities and respiration attain maximum at negative lag times. Lagging of respiration behind the central activities favors the central hypothesis of generation of NCSR. On the basis of comparison of PSD plots of a NCSR patient and a healthy patient we speculate that the vasomotor center of a NCSR patient assumes the control function in the respiratory control system. Clinical applications of the findings of the study may lead to the development of novel low-cost methods of diagnostic of NCSR based on easy-to-obtain electrocardiogram or electroencephalogram records of patients and emergence of some forms of "substitution therapy".

Cheyne-Stokes respiration is not related to quality of life or sleepiness in heart failure

BACKGROUND AND AIMS

The effects of central sleep apnea in Cheyne-Stokes respiration on sleep-related symptoms and quality of life are not very well established. We aimed to investigate whether Cheyne-Stokes respiration is related to health-related quality of life. We also studied the impact on daytime sleepiness and nocturnal dyspnea.

METHODS

Included were 203 consecutive patients, stabilized following in-hospital treatment for decompensated congestive heart failure. They underwent overnight cardiorespiratory sleep apnea recordings in hospital and answered a set of questions on symptoms and health-related quality of life questionnaires in the form of the Nottingham Health Profile and the Minnesota Living with Heart Failure Questionnaire. After excluding seven patients with predominantly obstructive apneas and 14 with insufficient recordings, 182 patients were included in the final analysis.

RESULTS

One third of the patients had an apnea-hypopnea index (AHI) of >30. Falling asleep in front of the television was the only symptom related to (AHI). Nocturnal dyspnea, daytime sleepiness, generic quality of life or disease-specific quality of life were not related to AHI.

CONCLUSIONS

Cheyne-Stokes respiration was not associated with health-related quality of life, daytime sleepiness or nocturnal dyspnea among patients stabilized following treatment for congestive heart failure.

Prevalence and characteristics of sleep apnoea in patients with stable heart failure: Results from a heart failure clinic

Background

Heart failure (HF) and sleep apnoea (SA) association has been recognized but whether it results from confounding factors (hypertension, ischaemia, obesity) remains unclear.

We aimed to determine the prevalence of SA in HF and to identify potential risk factors for SA in HF population.

Methods

We prospectively evaluated 103 patients with stable HF on optimized therapy. In-laboratory polysomnography was performed. Type and severity of SA were defined according international criteria. Demographic, anthropometric and clinical characteristics were collected. Continuous data are expressed as median and interquartile range.

Results

SA was found in 72.8%, moderate to severe in a significant proportion (apnoea-hypopnoea index ≥ 15- 44.7% of all patients) and predominantly obstructive (60.0% of patients with SA). Most patients were non-sleepy (Epworth < 10- 66%). SA patients were predominantly men (85.3 vs 60.7%, p-0.015), had larger neck (38.0 (35.0-42.0) vs 35.0 (33.2-38.0) cm, p-0.003), severe systolic dysfunction, (63.9 vs 33.3%, p-0.018), left ventricle (LV) hypertrophy (16.2 vs 0.0%, p-0.03), LV and left atria (LA) dilatation (49.0 (44.0-52.0) vs 42.0 (38.0-48.0) mm, p < 0.001; 60.0 (54.0-65.0) vs 56.0 (52.0-59.0) mm, p-0.01). However, only LA diameter was an independent predictor of SA. Higher body-mass index (BMI) was associated with moderate to severe SA. Patients with obstructive SA had larger neck and a trend for higher BMI, snoring and sleepiness. Hypocapnia was not associated with central SA.

Conclusions

In our HF population, SA was prevalent, frequently asymptomatic and without characteristic risk factors. Unlike previously reported, obstructive SA was the predominant type. These results suggest that SA is underdiagnosed in HF and there is a possible correlation between them, independent of confounding factors. Recent advances in HF therapy might influence prevalence and type of SA in this population.

Cor pulmonale due to congenital central hypoventilation syndrome presenting in adolescence

OBJECTIVE

To report the first case of congenital central hypoventilation syndrome (CCHS) presenting with severe cor pulmonale in an adolescent.

METHODS AND DESIGN

Case report and literature review. Our Institutional Review Board waived the need for consent.

SETTING

Pediatric intensive care unit in a tertiary care children's hospital.

PATIENT

A 12-year-old girl who developed profound hypoxia following routine dental extraction under intravenous opiate sedation and became progressively obtunded due to marked hypoventilation without hypoxic arousal, requiring mechanical ventilation. She had evidence of severe right heart failure, but no cardiac, pulmonary, neurologic, or neuromuscular cause was identified. The diagnosis of CCHS was suspected and subsequently confirmed by blood polymerase chain reaction analysis that revealed a heterozygous polyalanine expansion mutation of the PHOX2B gene (five polyalanine repeats).

CONCLUSIONS

This report describes the unusual presentation of severe cor pulmonale in an adolescent with so-called "late-onset" CCHS. CCHS was previously thought to be a disease affecting only neonates, but the late-onset phenotype has now been well described in adults. It should be considered in any child presenting with unexplained right heart failure without an identifiable cause, particularly if central sleep apnea is present, because early initiation of ventilatory support can prevent cardiac and neurologic sequelae and improve outcome.

6-Month CPAP-Treatment in a Young Male Patient with Severe Obstructive Sleep Apnoea Syndrome — A Case Study from the Couple's Perspective

BACKGROUND

Obstructive sleep apnoea syndrome (OSAS) is independently associated with an increased risk for hypertension and cardiovascular disease. Continuous positive airway pressure (CPAP) can reduce mortality and morbidity, but low compliance rates are seen.

AIM

To explore and describe the experiences of CPAP-treatment in a young male patient with severe OSAS during a 6-month period from the couple's perspective. METHODS AND THE CASE: A single case study with a phenomenographic approach was employed. Diagnostic procedures of OSAS and initiation of treatment with Auto-CPAP, humidifier and a nasal mask were performed during 4 visits. Conceptions were collected at 4 different occasions during the 6-month period (before, and 2 weeks, 3 months, and 6 months after treatment initiation) by means of interviews with a 33-year old male patient and his female partner.

FINDINGS

Totally 17 different structural aspects were found to fluctuate during the 6-month period in relation to; influence of stressors, social reactions and adaptation to increase compliance.

CONCLUSION

An increased knowledge about the influence of stressors, the social reactions, and the adaptation can help healthcare personnel to identify and better understand concerns of other patients and spouses during different time phases of the initial 6-month period of CPAP-treatment.

Sleep Disturbances in People Living With Heart Failure

Approximately 10% to 70% of people living with chronic heart failure (HF) experience significant sleep disturbances, which have been shown to impair their health-related quality of life and overall functional performance. Research findings, however, report inconsistent conclusions about sleep disturbances and their adverse effects on HF. The purpose of this article is to review several research studies addressing sleep disturbances in patients with HF and to highlight contradictory and inconsistent findings. Further nursing research about the phenomena related to sleep disturbances in people with HF is warranted so that evidence-based assessments and interventions can be tested in the future.

Nocturnal oxygen therapy prevents progress of congestive heart failure with central sleep apnea

BACKGROUND

Sleep disordered breathing has been reported to be associated with congestive heart failure (CHF). Nocturnal oxygen has been shown to abolish apnea. The aim of this study is to examine whether nocturnal oxygen reduces sympathetic nerve activity, and prevents progress of CHF.

METHODS

93 patients with left ventricular ejection fractions < 60%, were examined with overnight saturation monitoring for an oxygen desaturation index. Subjects with oxygen desaturation of 4% > or = 4/h were examined with polysomnography. Apnea-hypopnea index (AHI) was calculated as the total number of episodes of apnea and hypopnea per hour of sleep. We started nocturnal oxygen for the patients with AHI > or = 20. Urinary and plasma catecholamines concentrations, serum brain natriuretic peptide, human atrial natriuretic peptide, and endothelial nitric oxide synthase levels were measured before and after starting oxygen.

RESULTS

Compared among the three groups, CHF with central sleep apnea (CHF-CSA) group had significantly higher 24-h urinary adrenaline (CHF-CSA: 4.411+/-2.940 micromol/day, CHF with obstructive sleep apnea (CHF-OSA): 2.686+/-1.084 micromol/day, CHF without apnea (CHF-N): 3.178+/-1.778 micromol/day, P<0.05). Oxygen therapy significantly decreased AHI and 4 serum BNP levels (from 91.75+/-80.35 pg/ml to 52.75+/-45.70 pg/ml, mean change=33.85 pg/ml, P=0.0208). Serum eNOS levels were lower in CHF-CSA group and CHF-OSA group than in CHF-N group (CHF-CSA: 15.89+/-10.75 pg/ml, CHF-OSA: 7.46+/-3.91 pg/ml, CHF-N: 27.33+/-14.83 pg/ml, P<0.05).

CONCLUSIONS

Nocturnal oxygen may prevent progress of CHF with central sleep apnea.

Obstructive sleep apnoea syndrome ? patients' perceptions of their sleep and its effects on their life situation

AIM

This paper reports a descriptive study of how untreated patients with obstructive sleep apnoea syndrome perceived their sleep situation and how the syndrome affected their life situation.

BACKGROUND

Obstructive sleep apnoea syndrome is a prevalent problem independently associated with an increased risk for hypertension, cardiovascular disease, chronic heart failure and mortality. Increased consumption of healthcare resources can often be seen among patients over a long period of time since many have been undiagnosed and untreated.

METHODS

A phenomenographic approach was employed. Data were collected by interviews during 2005 with 20 purposively selected participants with untreated obstructive sleep apnoea syndrome. Findings. Participants described loud snoring, frequent awakenings, dyspnoea, frustration over nocturia, fear of dying during sleep and partners' anxiety about the apnoea, as being night-time effects of obstructive sleep apnoea syndrome. They described dry and sore throats, tiredness and daytime sleepiness, shame about falling asleep and snoring, thoughts about complications and depressed mood as daytime effects. Needs, such as increased alertness, improved ability to concentrate, improved relationship, adequate information as well as effective treatment, were described. Participants tried self-care strategies such as information-seeking about sleep disturbances and treatment, adapted sleeping routines, change of bedroom arrangements, adapted daily schedules, hyperactivity and avoidance of difficult situations.

CONCLUSION

The perceived effects and needs, as well as tried self-care actions by the patients with obstructive sleep apnoea syndrome in this study, could be used to identify and evaluate concerns of other patients with obstructive sleep apnoea syndrome waiting for treatment.

Central periodic breathing during sleep in acute ischemic stroke

BACKGROUND AND PURPOSE

It has been suggested that central periodic breathing during sleep (CPBS) may develop in unilateral supratentorial stroke without cardiopulmonary disease and disturbed consciousness. Not many data existed about such patients.

METHODS

Of 31 patients with first-ever stroke, we report 3 patients with CPBS in the absence of cardiopulmonary and vigilance disturbances. Patient assessments included polysomnography, MRI and echocardiography. Nocturnal breathing was reassessed after 1 to 3 months.

RESULTS

The patients had ischemic strokes in the left cingulate cortex, left insula and right paramedian thalamus. They were fully conscious when submitted to sleep recordings and lacked overt cardiovascular dysfunctions (ejection fractions=67%, 48%, 65%). CPBS was present during 18% to 24% of sleep. In all patients, breathing improved during stroke recovery.

CONCLUSIONS

CPBS may be present in strokes involving autonomic (insula) and volitional (cingulate cortex, thalamus) respiratory networks. As such, CPBS partly resolves within weeks.

Effects of long-term nocturnal oxygen treatment in patients with severe heart failure

Sleep-disordered breathing (SDB) is common in patients with heart failure (HF) and leads to disturbed sleep. The objective of this study was to determine the persistent effects of long-term nocturnal oxygen treatment in patients with severe HF regarding (1) objective outcomes, such as sleep, SDB, cardiac function, and functional capacity; (2) subjective outcomes, such as self-assessed sleep difficulties, daytime sleepiness, and health-related quality of life (HRQOL); and (3) the relationship between objective and subjective outcomes. In this open nonrandomized experimental study, 22 patients, median age 71 years, with severe HF were studied before and after 3 months of receiving nocturnal oxygen. The measures used were overnight polysomnography, echocardiography, 6-minute walk test, self-assessed sleep difficulties (Uppsala Sleep Inventory-HF), daytime sleepiness (Epworth Sleepiness Scale), and HRQOL (36-Item Short Form Health Survey and Minnesota Living with Heart Failure Questionnaire). SDB, with a 90% dominance of central sleep apnea, occurred in 41% of the patients with severe HF before intervention. After intervention, functional capacity improved for both the whole group of patients with HF (P < .01) and HF patients with SDB (P < .05). No improvements regarding cardiac function, objective sleep, subjective sleep, or SDB were seen, except for a decrease of > or = 4% desaturations (P < .05). HRQOL did not differ significantly between HF patients with and without SDB before or after intervention with nocturnal oxygen. Long-term nocturnal oxygen treatment improved functional capacity in patients with severe HF, with or without SDB. No improvements were seen regarding sleep, daytime sleepiness, SDB, cardiac function, or HRQOL.

Central periodic breathing observed on hospital admission is associated with an adverse prognosis in conscious acute stroke patients

BACKGROUND

Central periodic breathing (CPB) is common following acute stroke, but its prognostic significance is uncertain. We determined the frequency of CPB on admission with stroke and assessed whether it was related to outcome.

METHODS

We measured arterial oxygen saturation (SaO2), chest wall movements and nasal airflow continually with portable monitoring equipment in a large cohort of acute stroke patients, from arrival at hospital through acute assessment to reaching the ward. Baseline neurological examination and 3-month outcome (modified Rankin scale, MRS) were assessed blind to recordings. CPB was defined as cyclical rises and falls in ventilation, with intermittent reduced respiratory airflow or total apnoea.

RESULTS

CPB was common in acute stroke (33/138, 24%), but was poorly recognised by clinical staff. Patients with CPB were more likely to have a total anterior circulation syndrome and higher National Institutes of Health Stroke Scale scores than those without (both p<0.01). Patients with CPB had significantly higher median SaO2 than those without (p<0.01), unrelated to whether they received oxygen or not. At 3-month follow-up: 91% of patients with CPB were dead or dependent (MRS>or=3) compared with 53% of those without (OR 8.8; 95% CI 2.5-30.5); the association remained statistically significant after adjusting for covariates (OR 5.9; 95% CI 1.4-25.4).

CONCLUSION

CPB is independently associated with poor outcome after stroke, but is not by association with hypoxia. Further work is required to identify causes, effects and interventions that might improve effects of CPB.

Heart failure and sleep apnoea: to sleep perchance to dream

Heart failure and sleep apnoea are major health problems with an increasingly recognized association; evidence suggests that sleep apnoea may play a role in the progression of heart failure. However, confounding factors such as obesity, hypertension and coronary heart disease make this relationship uncertain and an independent correlation remains unproven. Diagnosis of sleep apnoea is suboptimal, as it is often asymptomatic and polysomnography is expensive and time-consuming. A simple and reliable screening protocol is required. All heart failure patients should be considered to be at high risk of sleep apnoea, as this association might be linked to adverse outcome. Continuous positive airway pressure has shown some beneficial effects, but long-term outcome and improvement in survival remains to be demonstrated. Despite recent advances in the understanding of the complex relationship between heart failure and sleep apnoea, there are a number of areas requiring further investigation, which may have important implications for the management and prognosis of a significant number of patients.

Palliative care for end-stage heart failure

Heart failure is growing in prevalence. Despite an array of treatments targeting a complicated pathophysiology, heart failure ultimately leads to death, and thus there is a clear need to provide palliative care to persons with end-stage heart failure. Palliative care, or education and support of the patient and family and management of distressing symptoms, should be provided throughout the course of the illness. Clinicians need additional information about how to palliate symptoms in advanced heart failure. This article summarizes recent reports about prognostication and identification of patients who are likely to die soon, and the management of fatigue, dyspnea, pain, and depression in heart failure. Palliative care or supportive care of the patient and family should be incorporated into comprehensive care throughout the course of heart failure. Data about hospice care for persons with heart failure are summarized.

The role of high-frequency jet ventilation in the treatment of Cheyne-Stokes respiration in patients with chronic heart failure

BACKGROUND

Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) is common in patients with severe cardiac failure. Various modes of positive airway pressure have been suggested as treatments. The authors hypothesized that high frequency jet ventilation (HFJV) can improve central sleep apnea in patients with chronic heart failure.

METHODS

Eleven subjects with stable, optimally treated chronic heart failure and Cheyne-Stokes respiration were tested untreated and on four treatment nights in random order: nasal oxygen (4 L/min), continuous positive airway pressure (CPAP) (mean 9.3 cm H(2)O), bilevel positive airway pressure (BiPAP)(mean 12.0/5.3 cm H(2)O), or HFJV(60 approximately 80 breaths per minute) during polysomnography (EMBLA, Flaga, Reykjavik, Iceland).

RESULTS

The apnea-hypopnea index (AHI) declined from 30.9 +/- 8.3/h in untreated night to 23.6 +/- 6.6/h oxygen night and 18.5 +/- 5.0/h CPAP, 14.3 +/- 3.9/h BiPAP, and 20.1 +/- 4.1/h HFJV (all P < 0.001 versus control). There was no significant difference between the AHI of HFJV and that of CPAP (P = 0.541). Arousal index decreased from 31.4+/-13.2/h untreated to 25.0 +/- 7.1/h oxygen and 13.6 +/- 4.7/h CPAP, to 13.7 +/- 4.9/h BiPAP and 14.4 +/- 4.7/h HFJV. HFJV had the similar effect to the other therapeutic groups in arousal index (P > 0.05). There were large increases in slow-wave and rapid eye movement (REM) sleep with HFJV. All subjects preferred HFJV to CPAP.

CONCLUSIONS

One night of therapy with HFJV improved nocturnal breathing pattern and sleep quality in patients with Cheyne-Stokes respiration in chronic heart failure. HFJV therapy for sleep and breathing were the same as those during a nasal CPAP night. A long-term study of the effect of HFJV on cardiovascular function is needed.

The role of behavioral sleep medicine in the assessment and treatment of sleep disordered breathing

With the dramatic rise in obesity in the United States, comorbid medical issues, such as sleep apnea and other forms of sleep disordered breathing (SDB), are becoming increasingly prevalent. Individuals with SDB have impairments in social, cognitive, and emotional functioning and an overall reduction in quality of life. Continuous positive airway pressure (CPAP) is the first-line treatment for SDB. CPAP use is associated with improvements in psychosocial functioning when individuals use the machine regularly. Unfortunately, CPAP adherence rates are often low. Patients sometimes discontinue CPAP therapy due to undesirable side effects, such as anxiety, insomnia, and nasal discomfort, or inconvenience. The goal of this review is to highlight the growing role of behavioral sleep medicine in the assessment and treatment of SDB and psychosocial impairments comorbid with SDB. More than any other health specialty, psychologists with behavioral sleep medicine experience are in the best position to treat psychiatric symptoms exacerbated by SDB-related sleep disturbances. Behavioral sleep medicine specialists also possess the expertise to address psychological obstacles to CPAP use. The assimilation of behavioral sleep medicine specialists into sleep clinics is likely to improve the overall quality of care for patients with SDB.

Heart failure in the elderly

Heart failure is the most common reason for hospitalization among older adults in the USA, and impacts five million people. Most people with heart failure are elderly, but in older people the management of the disease is complicated by comorbid conditions. Common problems in the elderly, such as dementia, frailty and depression, are more common in the elderly heart failure population. This review discusses an approach to identifying and managing these problems while managing heart failure. A suggested approach to older people with heart failure addresses the screening and integration of common geriatric problems into heart failure care.

Modified thoracic impedance plethysmography to monitor sleep apnea syndromes

BACKGROUND AND PURPOSE

In order to identify sleep disorders by thoracic impedance plethysmography (TIP), we propose several new techniques: the application of an adaptive filter, a scaled Fourier linear combiner (SFLC) to eliminate cardiac-derived fluctuation in the impedance waveform, and the use of heart rate variability (HRV) to ascertain whether the airflow is obstructed.

PATIENTS AND METHODS

Laboratory simulation experiments on four healthy individuals and actual overnight measurements on five patients with sleep disorders were carried out. Amplified thoracic impedance change (DeltaZ), ECG, a phonocardiograph, a pneumotachograph and a standard polysomnograph were recorded. The SFLC was applied to DeltaZ to selectively extract the cardiac-synchronous component (DeltaZ(CSC)), and the remainder of the waveform (DeltaZ(REM)) was low-pass filtered to estimate the waveform driven by respiration. The HRV was divided into respiratory synchronous (HRV(R)) and low frequency (HRV(L)) components.

RESULTS

The SFLC could drastically extract DeltaZ(CSC) from DeltaZ and thereby demonstrate a DeltaZ(REM) pattern quite similar to the flow-volume curve of the pneumotachograph. Central sleep apnea could be identified as the cessation of DeltaZ(REM) and concomitant attenuation of HRV(R). Obstructive sleep apnea could be identified as the maintenance of rhythmic but attenuated variations of DeltaZ(REM) accompanied by asynchronous fluctuation of HRV(R) against DeltaZ(REM). Central hypopnea could be identified as a normal but attenuated waveform in both DeltaZ(REM) and HRV(R). A large fluctuation in HRV(L) was observed during repetitive appearances of apnea/hypopnea in the nocturnal experiments.

CONCLUSION

The modified TIP together with HRV provides a superior tool for accurate and convenient definition of sleep apnea syndromes.

Impact of heart failure on quality of sleep

Chronic heart failure is an important health problem associated with a high mortality and morbidity. Appropriate treatment reduces mortality and leads to improved exercise tolerance but many patients report poor quality of sleep. Sleep studies of patients with heart failure suggest that sleep disordered breathing is experienced in 50% of patients and is a powerful predictor of poor prognosis. Sleep disordered breathing broadly comprises obstructive sleep apnoea, when upper airway instability causes mechanical obstruction to breathing; and central sleep apnoea, characterised by an absence of ventilatory effort. Sleep disordered breathing occurring in patients with heart failure is in most part attributable to central sleep apnoea and reflects uncompensated instability of the ventilatory feedback mechanism.

The human diving response, its function, and its control

The purpose of this review is to outline the physiological responses associated with the diving response, its functional significance, and its cardiorespiratory control. This review is separated into four major sections. Section one outlines the diving response and its physiology. Section two provides support for the hypothesis that the primary role of the diving response is the conservation of oxygen. The third section describes how the diving response is controlled and provides a model that illustrates the cardiorespiratory interaction. Finally, the fourth section illustrates potential adaptations that result after regular exposure to an asphyxic environment. The cardiovascular and endocrine responses associated with the diving response and apnea are bradycardia, vasoconstriction, and an increase in secretion of suprarenal catecholamines. These responses require the integration of both the cardiovascular system and the respiratory system. The primary role of the diving response is likely to conserve oxygen for sensitive brain and heart tissue and to lengthen the time before the onset of serious hypoxic damage. We suggest that future research should be focused towards understanding the role of altered ventilatory responses in human breath-hold athletes as well as in patients suffering from sleep-disordered breathing.

Consensus statement: Palliative and supportive care in advanced heart failure

BACKGROUND

A consensus conference was convened to define the current state and important gaps in knowledge and needed research on "Palliative and Supportive Care in Advanced Heart Failure."

EVIDENCE

Evidence was drawn from expert opinion and from extensive review of the medical literature, evidence-based guidelines, and reviews.

CONCLUSIONS

The conference identified gaps in current knowledge, practice, and research relating to prognostication, symptom management, and supportive care for advanced heart failure (HF). Specific conclusions include: (1) although supportive care should be integrated throughout treatment of patients with advanced HF, data are needed to understand how to best decrease physical and psychosocial burdens of advanced HF and to meet patient and family needs; (2) prognostication in advanced HF is difficult and data are needed to understand which patients will benefit from which interventions and how best to counsel patients with advanced HF; (3) research is needed to identify which interventions improve quality of life and best achieve the outcomes desired by patients and family members; (4) care should be coordinated between sites of care, and barriers to evidence-based practice must be addressed programmatically; and (5) more research is needed to identify the content and technique of communicating prognosis and treatment options with patients with advanced HF; physicians caring for patients with advanced HF must develop skills to better integrate the patient's preferences into the goals of care.

Cheyne-Stokes respiration in patients hospitalised for heart failure

BACKGROUND

Previous studies showing a strong relationship between Cheyne-Stokes respiration and the severity of left ventricular systolic dysfunction have usually been done in selected patient populations with lower age and a higher proportion of males than the "typical" in-hospital patient with heart failure. The purpose of the present study was test the strength of this relationship in unselected patients admitted to hospital due to decompensated chronic heart failure.

METHODS

We evaluated 191 patients (32% women), mean age 73 years, ready for discharge from the heart failure unit in the University Hospital of Malmo, Sweden. The patients underwent echocardiography for determination of left ventricular ejection fraction and left ventricular inner diastolic diameter. A respiratory investigation during sleep was performed the last night before discharge.

RESULTS

We found that 66% of the patients had Cheyne-Stokes respiration more than 10% of the total recording time. Only 7 (3.6%) of the patients had predominantly obstructive apnoeas. There was a significant but very weak relationship between left ventricular ejection fraction and left ventricular inner diastolic diameter on one hand and Cheyne-Stokes respiration on the other. Age was a stronger determinant of Cheyne-Stokes respiration than any of the cardiac or other clinical variables.

CONCLUSION

Although presence of Cheyne-Stokes respiration indicates left ventricular dysfunction, its severity seems only weakly related to the severity of heart failure. Age was found to be a stronger determinant, which may reflect the underlying age-dependency found also in healthy subjects. Due to age restrictions or other selection criteria, the importance of age may have been underestimated in many previous studies on factors associated with Cheyne-Stokes respiration.

Sleep Disturbance Symptoms in Patients With Heart Failure

Sleep disturbances have a major impact on physical functioning, emotional well-being, and quality of life, but are not well described in patients with heart failure (HF). Eighty-four HF patients completed a sleep survey and provided demographic and clinical data. Seventy percent of the patients were male with a mean age of 54 years and a mean left ventricular ejection fraction of 22%. Forty-seven patients (56%) reported trouble sleeping and one-third used sleeping medication. The most frequently reported problems were inability to sleep flat (51%), restless sleep (44%), trouble falling asleep (40%), and awakening early (39%). Using logistic regression, physiological variables were tested as predictors of sleep disturbance. Severity of HF, age, gender, etiology, obesity, smoking, and use of beta-blockers were not predictors of sleep disturbance. HF patients experience significant sleep disturbances, which are not predicted by severity of symptoms or clinical status. Problems with sleep are an important component of a clinical assessment in this vulnerable population.

[Noninvasive ventilation in the intensive care unit -- is it still negligible?]

Non-invasive positive pressure ventilation (NIPPV) has been discussed comprehensively in the last years, but usage of non-invasive ventilation in Intensive Care Units is rare. The reasons may be uncertainty in indications and difficulties in handling the masks and ventilators. In the last years the introduction of full face masks and respiratory helmets has made it possible to ventilate patients with unusual facial forms and to avoid problems of pressure necrosis. Software components designed for NIPPV are available for standard respirators. Indications for NIPPV (neuromuscular diseases, spinal abnormalities, chest wall malformations, COPD, cardiogenic pulmonary edema) have been ensured in clinical trials. No sufficient data are available for the application of NIPPV in weaning and respiratory failure following extubation. Indication for NIPPV becomes apparent when therapy starts in early stage with sufficient ventilation pressure. Compared to standard therapy, no reliable advantage has been seen for NIPPV in hypoxic hypercapnia respiratory failure except for malignant diseases. However, prophylactic use in patients with high risk might be conceivable. For these patients strict criteria of termination are required to avoid missing the time point for intubation. Gas exchange disturbances in advanced lung fibrosis, pneumonia and ARDS are not amenable to NIPPV. Contraindications for NIPPV are non-compliant patients, absence of cough- and pharyngeal reflexes as well as retention of secretions and malignant ventricular arrhythmia. Relative contraindications are catecholamine-dependent circulatory collapse and acute myocardial infarction, since sufficient data for NIPPV are missing.