Arrhythmogenic properties of disordered breathing during sleep in patients with cardiovascular disorders

The purpose of this study was twofold: to establish an ECG respiration monitoring system, and to evaluate the clinical usefulness of this system. Our purpose was to determine how many patients with cardiovascular disorders may have unrecognized sleep apnea and whether such apneic episodes are an important cause of cardiac arrhythmias. The study group included 81 patients, age range 40-95 years, and 13 healthy males, age range 52-72 years. The 24-h ECG respiration recordings were obtained with the two-channel holter recorder. Airflow at the nose using a nasal thermister or chest wall movement by impedance pneumography was recorded as respiration record on the second channel. Sleep apnea was observed 69% and 77-100% in the control subjects and patients with cardiovascular disorders, respectively. Episodes of sleep apnea were most frequent in the patients with old myocardial infarction. Grading of apneas was defined according to the length of apnea. Short duration apneas were observed only in the control subjects, but longer apneic episodes were observed in patients with cardiovascular disorders. Bradyarrhythmias observed were to be relative to apneic episodes longer than 20 s, while ventricular arrhythmias were observed only in the patients with old myocardial infarction, coincident with apneas lasting longer than 40 s. Atrioventricular conduction disturbances were also observed to be related to the occurrence of sleep apnea. These results suggest that 24-h ECG respiration monitoring is useful not only for the observation of sleep apneic episodes, but also in clarifying the relationship between cardiac arrhythmias and apneic episodes.     

Sleep apnea does not predict atrial flutter recurrence after atrial flutter ablation

Purpose  

Sleep apnea (SA) has been associated with atrial fibrillation (AF) and has been found to be a predictor of AF recurrence after successful pulmonary vein isolation. No investigations have been carried out to determine the prevalence of SA in patients with typical atrial flutter (AFL) and the impact of SA on AFL recurrence after AFL ablation. Our aim is to determine if SA is a predictor of recurrence of AFL and/or atrial arrhythmias in patients who have undergone AFL ablation.     

Schlafbezogene Atmungsst?rungen

Sleep related breathing disorders are common conditions and the management of patients with sleep apnea is an essential component of routine patient care. Daytime sleepiness is the leading symptom of sleep apnea but not mandatory. Especially patients with cardiac, pulmonary or metabolic comorbidities can benefit from treatment of sleep apnea and those patients should be considered for cardio-respiratory screening even with mild clinical symptoms. Continuous positive airway pressure therapy is still the most efficient treatment for sleep apnea and standard treatment for severe forms. With patient education, training and close follow-up a reasonably good compliance can be achieved in adequately selected patients. In mild forms of sleep apnea oral appliances may be efficient and in highly selected lean patients with anatomic risk factors upper airway surgery may be considered. Central sleep apnea, especially Cheyne-Stokes respiration, is highly prevalent in patients with severe cardiac insufficiency. If this disorder persists after cardiac treatment special ventilation modes like adaptive servo ventilation can be used.     

Sleep related breathing disorders

Sleep related breathing disorders are common conditions and the management of patients with sleep apnea is an essential component of routine patient care. Daytime sleepiness is the leading symptom of sleep apnea but not mandatory. Especially patients with cardiac, pulmonary or metabolic comorbidities can benefit from treatment of sleep apnea and those patients should be considered for cardio-respiratory screening even with mild clinical symptoms. Continuous positive airway pressure therapy is still the most efficient treatment for sleep apnea and standard treatment for severe forms. With patient education, training and close follow-up a reasonably good compliance can be achieved in adequately selected patients. In mild forms of sleep apnea oral appliances may be efficient and in highly selected lean patients with anatomic risk factors upper airway surgery may be considered. Central sleep apnea, especially Cheyne-Stokes respiration, is highly prevalent in patients with severe cardiac insufficiency. If this disorder persists after cardiac treatment special ventilation modes like adaptive servo ventilation can be used.     

Implantable pacing devices and sleep apnea: implications for diagnosis and therapy

Sleep apnea has been increasingly recognized for its prevalence and its impact on cardiovascular health. The disorder has considerable impact on cardiovascular disease states, particularly congestive heart failure. Implantable cardiac pacing devices may have a role in both the diagnosis and therapy of sleep apnea, which may be of particular importance given the seemingly wide coprevalence of cardiac disorders and sleep apnea.     

Systemic complications of acromegaly: epidemiology, pathogenesis, and management

This review focuses on the systemic complications of acromegaly. Mortality in this disease is increased mostly because of cardiovascular and respiratory diseases, although currently neoplastic complications have been questioned as a relevant cause of increased risk of death. Biventricular hypertrophy, occurring independently of hypertension and metabolic complications, is the most frequent cardiac complication. Diastolic and systolic dysfunction develops along with disease duration; and other cardiac disorders, such as arrhythmias, valve disease, hypertension, atherosclerosis, and endothelial dysfunction, are also common in acromegaly. Control of acromegaly by surgery or pharmacotherapy, especially somatostatin analogs, improves cardiovascular morbidity. Respiratory disorders, sleep apnea, and ventilatory dysfunction are also important contributors in increasing mortality and are advantageously benefitted by controlling GH and IGF-I hypersecretion. An increased risk of colonic polyps, which more frequently recur in patients not controlled after treatment, has been reported by several independent investigations, although malignancies in other organs have also been described, but less convincingly than at the gastrointestinal level. Finally, the most important cause of morbidity and functional disability of the disease is arthropathy, which can be reversed at an initial stage, but not if the disease is left untreated for several years.     

Sleep, the hypothalamic-pituitary-adrenal axis, and cytokines: multiple interactions and disturbances in sleep disorders.

Sleep is an important component of mammalian homeostasis, vital for survival. Sleep disorders are common in the general population and are associated with significant medical, psychologic, and social disturbances. Sleep, in particular deep sleep, has an inhibitory influence on the HPA axis, whereas activation of the HPA axis or administration of glucocorticoids can lead to arousal and sleeplessness. Insomnia, the most common sleep disorder, is associated with a 24-hour increase of ACTH and cortisol secretion, consistent with a disorder of central nervous system hyperarousal. Sleepiness and fatigue are very prevalent in the general population, and recent studies have demonstrated that the proinflammatory cytokines IL-6 and/or TNF-alpha are elevated in disorders associated with excessive daytime sleepiness, such as sleep apnea, narcolepsy, and idiopathic hypersomnia. Sleep deprivation leads to sleepiness and daytime hypersecretion of IL-6. Combined, these findings suggest that the HPA axis stimulates arousal, while IL-6 and TNF-alpha are possible mediators of excessive daytime sleepiness in humans.     

Obesity, Sleep Apnea Syndrome, and Rhythmogenic Risk

Obstructive sleep apnea is a common disorder and affects approximately 4% of middle-aged men and 2% of middle-aged women. Obstructive sleep apnea is clearly associated with obesity, with more than 50% of patients having a body mass index>30 kg/m2. Substantial evidence identified obstructive sleep apnea as risk factor not only for excessive daytime sleepiness and road traffic accidents, but also for increased cardiovascular morbidity and mortality. In addition, all kinds of arrhythmias have been observed in patients with sleep apnea ranging from asymptomatic sinus bradycardia to sudden cardiac death. Approximately 5-10% of patients with obstructive sleep apnea show marked apnea-related bradyarrhythmias due to enhanced vagal tone and pronounced hypoxia. Therapeutic options in obese patients with obstructive sleep apnea include consequent weight loss and nasal continuous positive airway pressure (CPAP) ventilation as the therapy of first choice. Weight reduction and effective nasal CPAP therapy significantly decrease cardiovascular morbidity and mortality and eliminate sleep-related bradyarrhythmias in 80-90% of patients obviating the need for pacemaker implantation in these patients.     

Cardiovascular consequences of obstructive sleep apnea

Sleep apnea is associated with several cardiovascular disease conditions. A causal relationship between sleep apnea and each of these diseases is likely, but remains to be proven. The clearest evidence implicating OSA in the development of new cardiovascular disease involves data that show an increased prevalence of new hypertension in patients with OSA followed over 4 years [3]. Circumstantial evidence and data from small study samples suggest that OSA, in the setting of existing cardiovascular disease, may exacerbate symptoms and accelerate disease progression. The diagnosis of OSA always should be considered in patients with refractory heart failure, resistant hypertension, nocturnal cardiac ischemia, and nocturnal arrhythmias, especially in individuals with risk factors for sleep apnea (e.g., central obesity, age, and male gender). Treating sleep apnea may help to achieve better clinical control in these diseases and may improve long-term cardiovascular prognosis.     

Sleep disorders in end-stage renal failure

Sleep disorders are common in patients with end-stage renal disease. Daytime sleepiness, restless legs syndrome, periodic limb movement disorder, insomnia, sleep apnea syndrome are the most disturbances. Usually, sleep-related complaints are attributed to uremia because of similar symptoms, and this may cause to delayed diagnosis. Sleep disorders are negative effect on quality of life and compliance to treatment of patients as well as cause increased mortality and morbidity. Therefore, sleep disorders should be evaluated as a different clinical entity in patients with chronic kidney failure or receiving renal replacement therapy. In this article, we aimed to review of etiology, pathogenesis and treatment of common sleep disorders in end-stage renal failure in sight of related literature information.     

Obstructive sleep apnea, cardiovascular disease, and pulmonary hypertension

With the growing epidemic of obesity in an aging population, obstructive sleep apnea (OSA) is increasingly encountered in clinical practice. Given the acute cardiopulmonary stressors consequent to repetitive upper airway collapse, as well as evidence for cardiovascular homeostatic dysregulation in subjects with sleep apnea, there is ample biologic plausibility that OSA imparts increased cardiovascular risk, independent of comorbid disease. Indeed, observational studies have suggested strong associations with multiple disorders, such as systemic hypertension, heart failure, cardiac arrhythmias, and pulmonary hypertension. Further data in the form of longitudinal cohort studies and randomized controlled trials are accruing to add to the body of evidence. This review examines pathophysiologic mechanisms and explores current concepts regarding the impact of OSA and its treatment on selected clinical disease states.     

A review of pediatric nonrespiratory sleep disorders

Sleep problems are extremely common during childhood, from infancy to adolescence. Despite the prevalence of sleep problems, childhood sleep disorders are often underrecognized and undiagnosed, despite being either preventable or treatable. Sleep impacts almost all aspects of a child's functioning, and thus the increased recognition and treatment of sleep disorders will positively affect a child's well-being. Children experience the same broad range of sleep disturbances encountered in adults, including sleep apnea, insomnia, parasomnia, delayed sleep phase, narcolepsy, and restless legs, but their clinical presentation, evaluation, and management may differ. Although snoring and sleep apnea may be the most common indication for an overnight sleep study in a child, one quarter of children presenting to a sleep clinic for evaluation will have a second sleep diagnosis, which is often nonrespiratory in nature. Especially in children, ruling out sleep apnea is rarely the end point of the sleep evaluation. Clinicians involved in sleep medicine must be prepared to recognize, evaluate, and manage plans for sleep disorders across the lifespan of the patient. This article will provide an updated review of nonrespiratory pediatric sleep disorders within a developmental framework.     

Sleep disorders. Obstructive sleep apnea syndrome,restless legs syndrome,and insomnia in geriatric patients

Sleep disorders may affect one out of two older Americans and may present as insomnia, excessive daytime sleepiness, or both. Age-related changes seem to cause a decreased need for sleep. The average 70-year-old sleeps only 6 hours a night, but may obtain an additional hour or even 2 during daytime naps. Older adults also experience an increase in the number of sleep disruptions and an increased incidence of chronic diseases, which can contribute to poorer sleep in this group. The two most common geriatric sleep disorders are obstructive sleep apnea syndrome and restless legs syndrome. Detailed diagnostic workup and treatment are usually referred to a center for sleep medicine where polysomnographic studies are performed. Left untreated, sleep disorders may present a serious threat to the patient's health and lead to increased morbidity and mortality.     

Sleep apnea and hypothyroidism: mechanisms and management

PURPOSE: There is a high incidence of sleep apnea in patients with untreated hypothyroidism. Thyroxine treatment is said to significantly reduce the apnea index and length and sleep apnea symptoms. We undertook a review of 10 consecutive hypothyroid patients with sleep apnea to investigate mechanisms and management of these two disorders. PATIENTS AND METHODS: Polysomnograms were obtained in 10 consecutive hypothyroid patients referred to our sleep disorders unit. All patients were studied while hypothyroid. Eight patients were restudied later when euthyroid. Lung function, blood gas values, and awake supraglottic resistance were also assessed in each patient. RESULTS: All 10 patients had sleep apnea and were treated with thyroxine. In one patient, hypothyroid myopathy involving the upper airway was demonstrated to be a potential mechanism of sleep apnea in hypothyroidism. Nocturnal angina and ventricular arrhythmias developed in two patients, despite the use of low thyroxine doses. Nasal continuous positive airways pressure (CPAP) was begun in eight patients. Initiation of CPAP prevented further angina or arrythmia in the patients with these cardiac complications. Six of the eight patients who were available for follow-up studies had persistent sleep apnea despite an euthyroid status (apnea index before thyroxine, 51 +/- 6; apnea index after thyroxine, 45 +/- 8), and CPAP therapy was continued in these patients. CONCLUSION: Our experience suggests that the apnea index does not decrease significantly in all patients with hypothyroidism and sleep apnea when euthyroidism is achieved. Treatment of hypothyroidism in the presence of sleep apnea is potentially hazardous and may lead to cardiovascular complications. Management by a combination of CPAP and low-dose thyroxine is helpful in this situation.     

Sleep disorders in the elderly: rationale for clinical awareness

Complaints about sleep are extremely common in the elderly, leading to an impression that aging-related sleep problems are virtually normal and benign. However, studies have shown that such complaints as habitual snoring, frequent awakening, nocturnal sweating, and awakening with anxiety, may be signs of genuine sleep disorders. The most prevalent and most serious aging-related sleep disorder is sleep apnea. There is recent evidence of an association between sleep apnea and circulatory disorders, including hypertension, stroke, and angina pectoris, and with reduced life expectancy. The older sleep apnea victim may not complain of daytime sleepiness, the usual symptom in younger patients. Sleep apnea, and several other sleep disorders of the elderly are treatable, once an accurate diagnosis is made. Physicians are urged to make questions about sleep as routine as the taking of blood pressure.     

Sleep disorders over the full range of chronic kidney disease

Sleep disorders are common and underrecognized in patients at all stages of chronic kidney disease. They include sleep apnea, insomnia, excessive sleepiness, restless legs syndrome and periodic limb movement disorder. They can be related to underlying uremia or comorbidities. Sleep disorders can affect the quality of life, and some are associated with increased morbidity and mortality. Clinical assessment, polysomnography and other standardized assessments are required for diagnosis. Therapeutic approaches include improvement in uremia management, treatment of comorbidities or specific interventions directed at individual sleep disorders. Diagnosis and treatment of sleep disorders in this population may improve quality of life and patient survival.     

Sleep apnea, delirium, depressed mood, cognition, and ADL ability after stroke

OBJECTIVES: The incidence of sleep apnea and stroke increases with age. The aim of this study was to investigate the presence of sleep apnea after stroke and its relationship to delirium, depressed mood, cognitive functioning, ability to perform activities of daily living (ADLs), and psychiatric and behavior symptoms. DESIGN: Cross-sectional study. SETTING: Geriatric stroke rehabilitation unit. PARTICIPANTS: 133 patients (78 women and 55 men, mean age 77.1 +/- 7.7 years) consecutively admitted to a geriatric stroke rehabilitation unit. MEASUREMENTS: All patients underwent overnight respiratory sleep recordings at 23 +/- 7 days (range 11 to 41 days) after suffering a stroke. The patients were assessed using the Organic Brain Syndrome Scale, Montgomery-Asberg-Depression-Rating Scale, Mini-Mental State Examination (MMSE), and Barthel-ADL Index. Sleep apnea was defined as an apnea-hypopnea index (AHI) of 10 or more. RESULTS: The median of the AHI for the studied sample (N = 133) was 13 (range 0-79; interquartile range 6-28). Fifty-nine percent fulfilled the criteria for sleep apnea; 52% with first-ever stroke had sleep apnea. More patients with sleep apnea than without were delirious, depressed, or more ADL-dependent. Sleep apnea patients also had a higher frequency of ischemic heart disease and had more often suffered from an earlier cerebral infarction. Multivariate analysis showed that obesity, low ADL scores, ischemic heart disease, and depressed mood were independently associated with sleep apnea. Low ADL scores, apnea-related hypoxemia, body mass index < or = 27, and impaired vision were independently associated with delirium. The presence of sleep apnea was not associated with any specific type of stroke or location of the brain lesion. CONCLUSIONS: Sleep apnea is common in stroke patients and is associated with delirium, depressed mood, latency in reaction and in response to verbal stimuli, and impaired ADL ability. We suggest a trial investigating whether delirium, depressed mood, and ADL ability improve with nasal continuous positive airway pressure treatment of sleep apnea in stroke patients.     

Trauma and syncope-evidence for further sleep study? A case report

We report on an 83-year-old male with traumatic brain injury after syncope with a fall in the morning. He had a history of seizures, coronary artery disease and paroxysmal atrial fibrillation (AF). No medical cause for seizures and syncope was determined. During rehabilitation, the patient still complained of seizures, and also reported sleepiness and snoring. Sleep apnea diagnostics revealed obstructive sleep apnea (SA) with an apnea-hypopnoea index of 35/h, and sudden onset of tachycardia with variations of heart rate based on paroxysmal atrial fibrillation. Additional tests showed nocturnal AF which spontaneously converted to sinus rhythm mid-morning with an arrest of 5 s (sick sinus syndrome) and seizures. A DDD-pacer was implanted and no further seizures occurred. SA therapy with nasal continuous positive airway pressure was refused by the patient. Our findings suggests that screening for SA may offer the possibility to reveal causes of syncope and may introduce additional therapeutic options as arrhythmia and SA often occur together which in turn might be responsible for trauma due to syncope episodes.     

阻塞性睡眠呼吸暂停低通气综合征与心律失常

阻塞性睡眠呼吸暂停低通气综合征（OSAHS）是一种睡眠过程中反复出现的以呼吸暂停、睡眠结构紊乱及低氧血症等为特征的疾病.大量的临床研究证明0SAHS与高血压、代谢综合征、冠心病、心力衰竭、脑卒中以及心律失常等疾病密切相关,现通过系统综述,探讨分析了OSAHS与多种心律失常发生的关系,归纳总结其发生机制及心电学特点,并对OSAHS及其合并症的治疗进展进行相关讨论.     

Experimental study on the relationship between cardiac arrhythmias and sleep states by ambulatory ECG-EEC monitoring

The relationship between cardiac arrhythmias and sleep states was investigated in rats using the ambulatory ECG-EEG monitoring system under the 14/10 light-dark illumination schedule. Records of 14 rats obtained over 94 days were analyzed. Bradyarrhythmias (SA block and AV block) and ventricular arrhythmias [ventricular premature contraction (VPC) and short run of VPCs (ventricular tachycardia, VT)] were observed. Average number of episodes of bradyarrhythmia per day was 7.5, and the ratio of SA block to AV block was 34.9% to 65.1%. Average VPC or VT occurrence per day was 0.9 or 0.1 times, respectively. Sleep states were divided into alertness, slow-wave sleep, and paradoxical sleep, and the relationship between sleep states and arrhythmias was investigated. Bradyarrhythmias appeared predominantly during paradoxical sleep, while ventricular arrhythmias appeared during alertness as well as paradoxical sleep. Bradyarrhythmic episodes decreased by right or left vagotomy 78% or 70%, respectively. Sinus bradyarrhythmias disappeared almost completely by the right vagotomy, while the occurrence of AV block decreased by the right or left vagotomy. Circadian rhythms in arrhythmias were also analyzed by the cosine-fitting technique, and significant circadian rhythms were demonstrated in both bradyarrhythmias and ventricular arrhythmias. Acrophases were 9:56 A.M. and 1:47 A.M., respectively. Occurrence of VT was rare, but the most frequent incidental time zone was immediately following transition from light effects (rest) to dark (activity). This knowledge of circadian rhythm effects in arrhythmias must be incorporated into improved treatment of arrhythmias.