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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This overview discusses pathogenesis, clinical presentation, prognostic implications and therapy of central sleep apnea with special reference to Cheyne-Stokes-Respiration or periodic breathing. In contrast to obstructive sleep apnea due to upper airway collapse during sleep, central sleep apnea (CSA) is mainly due to an instability of the breathing control system. Causes of central sleep apnea include alveolar hypoventilation disorders, heart failure, neurologic and autonomic disorders and idiopathic forms of CSA. Patients with idiopathic CSA often complain of insomnia and awakening during sleep but may also suffer from daytime sleepiness. Cheyne-Stokes-Respiration or peridic breathing is often associated with heart failure and neurological disorders especially those involving the brainstem. In heart failure periodic breathing has enormous prognostic implications. Treatment options for central sleep apnea are oxygen supplementation, medical therapy (i.e. acetazolamide) and CPAP. For patients with central sleep apnoea associated with alveolar hypoventilation nasal ventilation is treatment of choice. Newer nasal ventilation techniques (BiPAP, AutoSetCS) are under investigation for heart failure patients with Cheyne-Stokes-Respiration.
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PMID:[Central sleep apnea syndrome and Cheyne-Stokes respiration]. 1095 54

Ageing is often associated with a decrease in the quality of sleep. In older subjects, sleep-related breathing disorders (SRBD) are increasingly recognized as being responsible for alterations in the quality of sleep. The prevalence of obstructive sleep apnea (OSA) increases with ageing; despite sometimes major disturbances in sleep structure, clinical symptoms are often subtle in this age group. Central apnea and periodic breathing, also more frequent in older subjects, most often occur in patients suffering either from neurological problems (such as tumors, brain infarcts, sequelae of infection, diffuse encephalopathies) or moderate to severe heart failure. In fact, patients suffering from cerebro-vascular diseases (such as brain infarcts or transient ischemic attacks) have a higher prevalence of SRBD than a control age-matched population. In these patients, SRBD are associated with a poorer prognosis in terms of functional recovery and survival. The clinical impact of SRBD on cognitive function appears to be modest in patients without dementia, albeit for a slight increase in daytime somnolence. However, in patients suffering from Alzheimer's disease, SRBD occur more frequently than in non-demented subjects, and indexes of severity of SRBD have been correlated with the importance of cognitive impairment. The hypothesis of a causal relationship between SRBD and the degree neuropsychological impairment in either Alzheimer's disease or multi-infarct dementia remains a matter of controversy. SRBD should be considered as a possible cause of "reversible dementia" and sought for in the presence of daytime somnolence, delirium, or unexplained right-sided heart failure in older patients.
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PMID:[Respiratory sleep disorders in the elderly]. 1114 Mar 5

Sleep disordered breathing (SDB), i.e., obstructive, central or mixed sleep apneas, has been recognized as a common occurrence in the elderly. Aging is per se associated with a decrease in the quality of sleep; SDB may further disrupt the sleep architecture in older subjects. The prevalence of obstructive sleep apnea (OSA) increases with aging; available studies report prevalence rates of 11-62%. Furthermore, OSA has been associated with increased mortality in older adults. Central apneas and periodic breathing occur with increased frequency either in subjects with neurological disorders such as infarction, tumor, sequelae of infection, diffuse encephalopathies, or in chronic heart failure. Patients with cerebrovascular disease (stroke, or transient ischemic attacks) have a markedly high prevalence of SDB, mainly OSA. In these patients, SDB is associated with a poorer functional prognosis at 3 and 12 months after the acute event, and a higher mortality. The clinical impact of SDB on cognitive function appears to be modest in patients without dementia, although there is a moderate increase in daytime sleepiness. In Alzheimer's disease (AD) however, SDB occurs more frequently than in non-demented older subjects, and its severity is correlated with the degree of cognitive impairment. The hypothesis of a causal relationship between AD and SDB remains a subject of controversy. The possibility of SDB should be considered in the elderly in the differential diagnosis of "reversible dementias", increased daytime sleepiness, or unexplained right-sided heart failure.
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PMID:Sleep disordered breathing in the elderly. 1121 51

Chemoreceptors are known to respond to changes in composition of the gases in the inspired air by changing pulmonary ventilation. Whereas, less known it is the role that they play in many both physiologic and pathologic conditions. In this review we do not only consider the anatomic and physiologic chemoreceptor features but also we analyse the relationship between chemoreflex and baroreflex in the cardiovascular control, their role in the pathogenesis of essential hypertension and in the increase of blood pressure in subjects affected by obstructive sleep apnea, their implication in the genesis of dyspnea in chronic heart failure and their role in pulmonary disease. In this review we also analyse the chemoreflex changes with relation to physiologic situations such as aging, obesity, exercise, training and high altitude. Three methods are described for the study of the chemoreflex function, but more attention is paid to the new rebreathing technic. The aim of this paper is to underline the interactions between chemoreceptors and cardiovascular system and to analyse their functional changes in both physiologic and pathologic conditions.
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PMID:[Functions and changes of chemoreflex in physiological and pathological conditions]. 1147 84

Patients with obstructive sleep apnea (OSA) are at increased risk for cardiovascular disease. Altered cardiovascular variability is a prognostic indicator for cardiovascular events. This review examines the evidence that OSA is accompanied by alterations in cardiovascular variability. This alteration is evident even in the absence of hypertension, heart failure or other disease states, and may be linked to the severity of OSA. The presence of clear-cut abnormalities in time and frequency-domain measures of blood-pressure and heart-rate variability in normotensive OSA patients provides intriguing evidence for the concept of an etiologic interaction between sleep apnea and cardiovascular disease. Mechanisms that could contribute to altered cardiovascular variability in patients with sleep apnea include abnormalities in chemoreflex, baroreflex and endothelial function.
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PMID:Cardiovascular variability characteristics in obstructive sleep apnea. 1148 97

There is emerging evidence linking obstructive sleep apnea (OSA) to vascular disease, including hypertension. This relationship may be independent of co-morbidity, such as obesity. Even apparently healthy OSA patients have evidence of subtle functional vascular abnormalities that are known to occur in patients with hypertension and atherosclerosis. Untreated OSA may possibly contribute to the initiation and/or progression of pathophysiologic mechanisms involved in hypertension, heart failure, cardiac ischemia and stroke. This brief commentary will examine the evidence and mechanisms linking OSA to vascular disease.
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PMID:Obstructive sleep apnea and vascular disease. 1173 28

Snoring is a nuisance at least! The inspiratory vibrations of pharyngeal soft tissue may exceed 85 dB. For thousands of years snoring has led to social and marital disharmony in many cases. The treatment of the symptom snoring has been of interest for the medical profession for the same time. Today, we know that snoring is the most common presenting symptom of obstructive sleep apnea (OSA). The wider recognition of OSA and its impact on the development of systemic and pulmonary hypertension, cardiac arrhythmias, heart failure and daytime sleepiness has occurred in the last decade. The treatment of OSA has become a medical issue apart from its social aspects.
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PMID:UPPP or LAUP: Is This All Surgeons Should Talk About? 1189 7

Heart failure has an increasing prevalence in middle age adults. The prognosis is very poor even with improved medical therapy and heart transplants. The outcome is related to the neurohumoral disease resulting from heart failure which leads to sympathetic activation that in turns worsens the prognosis. About half of the patients have sleep breathing disorders with variable proportions of central and obstructive apneas. Obstructive apneas are acutely deleterious to ventricular function. On the long run, they may be responsible for a worsening of the disease due to the permanent sympathetic activation seen in obstructive sleep apnea. It is therefore important to detect sleep apnea in patients and to apply a treatment. The best therapeutic procedure in obstructive events appears to be CPAP, provided hemodynamic status is closely monitored.
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PMID:[Obstructive sleep apnea syndrome and heart failure]. 1192 36

Recent epidemiologic studies indicate that approximately 40 to 50% of stable patients with congestive heart failure (CHF) suffer from either obstructive sleep apnea (SA) or Cheyne-Stokes respiration with central SA. In either type of sleep apnea, several mechanisms contribute to significant mechanical and adrenergic stresses upon the failing myocardium. These include hypoxemia, reductions in intrathoracic pressure, rises in systemic arterial pressure, increases in left ventricular afterload, and arousals from sleep worsening the sleep architecture. Consequently, sympathetic activation and parasympathetic withdrawal are the hallmark of sleep-related sleeping disorders that contribute to the progression of heart failure and may adversely affect its prognosis. On the other hand, recent studies indicate that successful treatment of either type of SA with continuous positive airway pressure in patients with CHF results in objective and subjective improvement in the severity of heart failure increases in left ventricular ejection fraction, and reductions in sympathetic nervous system activity. Therefore, the early diagnosis and specific treatment of either obstructive or central SA in patients with CHF is highly warranted.
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PMID:Cardiovascular implications of sleep apnea in patients with congestive heart failure. 1244 40

Apparent life-threatening event (ALTE) is a term used to define an event of unknown cause after an infant is found limp, cyanotic, bradycardic, and/or requires resuscitation. Eight to 15% of children with ALTE die of sudden infant death syndrome. Obstructive sleep apnea, bradycardia, gastroesophageal reflux, and laryngotracheal abnormalities are frequently associated with ALTE. Wide QT dispersion is associated with sudden death in heart failure and increased risk of ventricular fibrillation in acute myocardial infarction. Here, we assess QT dispersion in infants with ALTE and its correlation to clinical and electrocardiographic indices. The study included eighty nine infants (age 2.14 +/- 1.8 months, 46 males and 43 females) referred with ALTE to the pediatric emergency room and 18 controls (age 2.77 +/- 2.2 months) who underwent electrocardiogram assessment of QTmin, QTmax, QT dispersion (QT-D), and as well as QTmin, QTmax, and QT-D corrected for heart rate (QTcmin, QTcmax, QTC-D, respectively). All infants were referred at the usual diagnostic tests-the gastroesophageal reflux test, apnea monitoring, Holter ECG monitoring, electroencephalogram, and Doppler echocardiography. QT-D, QTc-D, and QTc-min were significantly greater in the ALTE group (p < 0.01). Greater QTc-D was found in males compared to females (p < 0.001). QT-D and QTc-D showed little or no correlation with age of infant or positivity of diagnostic tests. QTc has been found by multiple regression analysis to be the independent variable with the greatest impact on QTc-D (beta = -0.68, p < 0.001).
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PMID:QT dispersion in infants with apparent life-threatening events syndrome. 1253 Apr 92


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