[Cheyne-Stokes respiration and cardiovascular risk]. / Cheyne-Stokes-Atmung und kardiovaskuläres Risiko.

Due to its high prevalence in patients with heart failure and its negative predictive value concerning morbidity and mortality, Cheyne-Stokes respiration (CSR) is a sleep disorders of major interest. CSR correlates with the degree of heart failure and is characterised by a typical crescendo/decrescendo breathing pattern combined with phases of central sleep apnoea, caused by pulmonary oedema and oscillation of ventilatory control. Thus, CSR is a marker of the severity of heart failure. Treatment of CSR first involves optimisation of heart failure therapy by cardiologists and then application of non-invasive means of ventilatory support. Treatment of patients with severe heart failure with non-invasive positive pressure ventilatory support leads to a significant reduction of CSR, sympathetic activity, and daytime sleepiness and improves cardiac output and 6-minute walking distance. At present, a prospective randomised, controlled intervention-study (Serve-HF study) is being conducted in order to show if therapy of CSR can improve patient survival. This review describes the pathophysiology, epidemiology, and therapeutic options of CSR with a special focus on the elevated cardiovascular risk of patients with CSR.

[Acute effects of cardiac resynchronization therapy on breathing during sleep in patients with severe chronic heart failure--a pilot study]. / Akuteffekte einer kardialen Resynchronisationstherapie auf die Atmung im Schlaf bei Patienten mit fortgeschrittener Herzinsuffizienz--Eine Pilotstudie.

BACKGROUND: Sleep-related breathing disorders (SDB), especially Cheyne-Stokes respiration (CSR), have prognostic relevance in patients with chronic heart failure (CHF). Thus, we investigated acute effects of cardiac resynchronization therapy on breathing during sleep. METHODS: Beside a cardiopulmonary investigation, breathing during sleep was analysed polygraphically/polysomnographically on the night before and during the second night after implantation of a biventricular pacemaker for cardiac resynchronization. PATIENTS: We investigated 16 consecutive patients with severe CHF (NYHA class III-IV) and widened QRS complexes (QRS > 150 ms) with the indication for cardiac resynchronization therapy independent of this study. RESULTS: Cardiac resynchronization therapy shortened the QRS time in each and every patient (QRS: 167.3 +/- 21.7 ms to 113.0 +/- 19.0 ms; p < 0.001) as a marker for successful resynchronization. Initially, SDB were diagnosed in 11 of the 16 patients studied (69 %), with 7 patients having CSR (44 %) and 4 patients (25 %) having CSR and obstructive sleep apnoea. With cardiac resynchronization therapy, no significant acute changes were seen regarding nocturnal breathing/breathing disorder, heart frequency, or oxygen saturation. CONCLUSIONS: The established positive effects of cardiac resynchronization therapy are rather due to a chronic improvement of cardiopulmonary interactions (remodelling, circulatory time, or chemosensitivity) than to acute effects, as investigated in this study.

[Pathophysiology of the obesity hypoventilation syndrome]. / Obesitas-Hypoventilationssyndrom--Pathophysiologische Aspekte.

The obesity hypoventilation syndrome (OHS) is defined by extreme overweight (BMI 30 kg/m2), daytime hypoventilation (PaCO2 > 45 mm Hg, the absence of other known causes of hypoventilation) and sleep-related breathing disorders. Obesity impairs breathing due to a restrictive ventilatory disorder, reduction of the capacity of respiratory muscles and diminishment of the ventilatory response. The restriction cannot serve as the only explanation of OHS because body weight or compliance on the one hand and hypoventilation on the other hand only correlate weakly. Obesity increases the work of breathing by greater body mass with its increased oxygen demand, impaired diaphragmatic mobility, upper airway obstruction, and oxygen desaturation which result in an inadequacy of oxygen demand and supply. The adjustment of the chemoreceptors can avoid the overload on the capacity of the respiratory muscles, at least in a number of patients or in the course of the disease. This disproportion results in hypercapnia. Furthermore, the level of leptin is an important factor in the pathophysiology of OHS. The blood level of leptin correlates with the body fat mass in humans. However, there seems to be a relative leptin deficiency in the brain in overweight humans. Therefore, in contrast to animals, leptin cannot sufficiently increase ventilation in man to avoid hypercapnia.

[Influence of nocturnal oxygen therapy on quality of life in patients with COPD and isolated sleep-related hypoxemia: a prospective, placebo-controlled cross-over trial]. / Einfluss der nächtlichen Sauerstofftherapie auf die Lebensqualität bei Patienten mit COPD und isolierter schlafbezogener Hypoxämie: Eine prospektive, plazebokontrollierte cross-over Studie.

BACKGROUND: In patients with COPD and isolated night time hypoxemia, oxygen administration has not shown any effects on life expectancy and the development of pulmonal arterial hypertension. The aim of the present pilot study was to investigate the influence of nocturnal oxygen therapy on the quality of life in daytime normoxemic COPD patients with nocturnal oxygen desaturations. PATIENTS AND METHODS: 19 patients with COPD, in a stable phase of the disease without need for oxygen supplementation under rest (PaO2 62.7 +/- 4.9 mmHg) and nocturnal hypoxemia (t90 = 55.5 +/- 33.4 % of registration time, mean SaO2 89.8 +/- 1.9 %, minimal SaO2 81.1 +/- 4.8 %) were randomly assigned to either oxygen or placebo treatment, both generated by identical concentrator devices. Each treatment period lasted 6 weeks, after six weeks a cross-over was performed by a technician. Quality of life was assessed before and at the end of each treatment period by the SF-36, Nottingham Health Profile and Saint George's Respiratory Questionnaire. RESULTS: Significant differences for the comparison of placebo and verum were only seen for the dimension sleep (NHP), all other dimensions showed no differences between placebo and oxygen. However, both placebo and oxygen improved the majority of the quality of life items significantly. CONCLUSIONS: The prescription of supplemental oxygen in COPD patients with isolated nocturnal hypoxemia in the present pilot study is not able to improve the quality of life within 6 weeks after initiation of therapy. It cannot, therefore, be generally recommended, but may be indicated in patients with a documented improvement of sleep quality.

[Daytime ventilatory efficiency in obstructive sleep apnea syndrome--influence of CPAP-therapy]. / Einfluss der CPAP-Therapie auf die ventilatorische Effizienz am Tage bei Patienten mit obstruktivem Schlafapnoe-Syndrom.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is a nocturnal breathing disorder with possibly negative consequences on daytime control of ventilatory drive. We therefore investigated ventilatory efficiency, defined as the ventilatory equivalent for CO2 (VaE/VaCO2), in patients with OSAS during exercise before and under treatment with continuous positive airway pressure (CPAP). PATIENTS AND METHODS: In 21 patients with untreated OSAS, ventilatory efficiency, described as the slope (DeltaVaE vs. VaCO2) and the lowest ratio (VaE/VaCO2 min) of the ventilatory equivalent for CO2, was determined below the anaerobic threshold using spiroergometry. A follow-up after at least 6 months of CPAP therapy was performed in 16 of these patients and in 5 CPAP-neglecting patients with OSAS, who served as controls. RESULTS: In 21 patients with untreated OSAS, DeltaVaE vs. VaCO2 was significantly and VaE/VaCO2 min non-significantly lower, revealing better ventilatory efficiency, compared to normal values. In 16 patients, ventilatory efficiency did not change after on average 305.7 +/- 104.8 nights of CPAP-therapy, compared to 5 controls. CONCLUSIONS: OSAS is not associated with a disturbed ventilatory efficiency during exercise. Long-term CPAP-therapy does not change ventilatory efficiency during exercise in patients with OSAS. The improved ventilatory efficiency during exercise compared to normal controls may be due to differences concerning anthropometric data (e. g., obesity, hypertension) and cardiopulmonary exercise-test (45 degrees lying position).

[Sleep apnoea in women?--The forgotten gender]. / Schlafapnoe bei Frauen?--Das vergessene Geschlecht.

The prevalence of clinically relevant, obstructive sleep apnoea syndrome (OSAS) in the general population is 2% in women and 4% in men. With increasing age and onset of postmenopausal status, the prevalence of OSAS in women becomes comparable to that of males. However, compared to prevalence data, women are under-represented in clinical sleep laboratories. The present overview deals with the potential reasons for clinical under-recognition of OSAS in women. The fact that OSAS frequency is underestimated in women probably derives from the atypical clinical symptoms, dominated by difficulties of initiating and maintaining sleep and by a depressive mood. There are several protecting mechanisms in women that prevent or postpone OSAS development to higher age groups or until the onset of menopause. These factors include craniofacial morphology and function, gender-specific body-fat distribution and hormonal influences on ventilation and dilating muscles in the oropharynx. Physicians should be aware of the presence of sleep-disordered breathing in women and of their special features.

[Locus of control belief is a predictor of CPAP-compliance in patients with obstructive sleep apnea syndrome]. / Die Kontrollüberzeugung ist ein Prädiktor für CPAP-Compliance bei obstruktivem Schlafapnoesyndrom1.

Approximately 25 % of all patients suffering from obstructive sleep apnea syndrome (OSAS) discontinue CPAP-therapy in long-term follow-up. This study was conducted to investigate if there are any predictors signaling low compliance prior to initiation of CPAP-therapy. We used an open label longitudinal cohort study at an University hospital in-patient Sleep laboratory setting. In 85 consecutive patients with a diagnosis of OSAS confirmed by polysomnography a CPAP-therapy was initiated. Prior to CPAP-titration the subjects were interviewed using standardized, validated questionnaires (Nottingham Health Profile, von Zerssen's Depression Scale, State Trait Anxiety Inventory, IPC-Scale). On follow up (mean 16 +/- 8 month) 66 patients were still using CPAP regularly, 19 individuals had discontinued the therapy. Data of both groups were compared. There were no significant differences in polysomnographic parameters before CPAP except apnea-hypopnea-index (users: 30.72 +/- 20.68, rejecters: 18.43 +/- 10.43) and mean oxygen saturation (users: 91.65 +/- 3.32, rejecters 93.63 +/- 1.86). Depression and anxiety levels were normal in both groups. The subjects who discontinued CPAP had a significantly less external control belief. Internal control belief was normal in all patients. It is suggested that individuals who discontinued CPAP could not be convinced of the necessity of CPAP by physicians or nurses due to their reduced external control belief. Identifying patients with diminished external control belief prior to prescription of a device might be useful. In selected subgroups, different methods of motivation to maintain long-term acceptance for CPAP-therapy seems to be necessary.

Tuberculous involvement of the oesophagus with oesophagobroncheal fistula.

Tuberculous involvement of the oesophagus is a rare disease. Even if it is suspected, diagnosis is often difficult though dysphagia and chest pain are the most common symptoms without any other specific signs of tuberculosis. The diagnosis is based on oesophagography, oesophagoscopy, bronchoscopy, and computed tomographic scan. Suspected tuberculosis can be confirmed with histology, smear, and culture. The two most common differential diagnoses are Crohn's disease and carcinoma. The case is reported of a female patient with tuberculous involvement of the oesophagus, who developed an oesophagobroncheal fistula during steroid treatment started for suspicion of Crohn's disease. The patient was immunocompromised due to treatment with azathioprine that she was receiving for multiple sclerosis. The fistula was successfully treated by antituberculous chemotherapy alone.

Driving performance in patients with chronic obstructive pulmonary disease.

Patients with chronic obstructive pulmonary disease (COPD) present with impairments of their cognitive performance. It is still unknown whether cognitive deficits influence driving abilities in patients with COPD. The present study investigates driving performance in patients with COPD and healthy controls. Driving simulation was performed in 17 patients with COPD and 10 healthy controls. Patients with COPD demonstrated significantly worse results in terms of accident frequency in the simulated driving situation. No correlations existed between the severity of disease, assessed from the polysomnographical findings (e.g., lung function, blood gas analysis, sleep disturbance, nocturnal ventilation, and oxygen saturation), and driving performance. We conclude that impairments of driving performance in patients with COPD cannot be predicted on the basis of the severity of the disease. The impairment of driving performance in the simulated driving situation in COPD patients may have crucial consequences for driving licensing in these patients.

[Pulmonary diseases and heart function]. / Lungenerkrankungen und Herzfunktion.

The most severe cardiac sequel to lung disease is the load on the right ventricle due to pulmonary hypertension with the development of a cor pulmonale. This is characterized by hypertrophy and/or dilatation of the right ventricle because of a primary impairment of lung function and/or lung structure. The most important pathomechanisms for the development of pulmonary hypertension are vessel obliteration, mechanical lesions, primary vascular or extra-vascular inflammation and hypoxic vasoconstriction. Chronic obstructive pulmonary disease (COPD) is one of the most important reasons for chronic cor pulmonale. A further very common reason is obstructive sleep apnea syndrome, especially if combined with a COPD. In this case, the prevalence of cor pulmonale can reach 80%. The development of a chronic cor pulmonale is the most striking negative prognostic factor for these patients. Only 30% of COPD patients with cor pulmonale survive longer than 5 years, and only early detection of the disturbances to respiration which might potentially lead to cor pulmonale and their subsequent therapy are able to improve the patient's prognosis. Furthermore, pulmonary diseases may also have an impact on the left heart side in terms of an impairment of left heart function or by inducing severe arrhythmias . Thus, lung diseases may have both a significant impact on right and left heart performance.

Sleep apnoea in heart failure.

Studies from the USA have reported that sleep apnoea is common in congestive heart failure (CHF), with Cheyne-Stokes respiration (CSR) being the most frequent type of sleep-disordered breathing (SDB) in these patients. Within the present study, the authors sought to assess the prevalence and type of SDB among CHF patients in Germany. A total of 203 CHF patients participated in this prospective multicentre study. All patients were stable in New York Heart Association classes II and III and had a left ventricular ejection fraction (LVEF)<40%. The patients were investigated by polygraphy and all data were centrally analysed. Patient enrolment was irrespective of sleep-related symptoms. The majority of patients were male with a mean age of 65 yrs and hospitalised. Of the 203 patients, 145 (71%) had an apnoea/hypopnoea index>10.h(-1), obstructive sleep apnoea (OSA) occurred in 43% (n=88) and CSR in 28% (n=57) of patients. The prevalence of sleep-disordered breathing is high in patients with stable severe congestive heart failure from a European population. As sleep-disordered breathing may have a negative impact on the prognosis of congestive heart failure, a sleep study should be performed in every patient with congestive heart failure and a left ventricular ejection fraction of <40%. This diagnostic approach should probably be adopted for all of these patients irrespective of the presence of sleep-related symptoms.

[Sleep-related breathing disorders--a second edition of the International Classification of Sleep Disorders (ICSD-2) of the American Academy of Sleep Medicine (AASM)]. / Schlafbezogene Atmungsstörungen--Neuauflage der Internationalen Klassifikation von Schlafstörungen (ICSD-2) der American Academy of Sleep Medicine (AASM).

In 2005 the American Academy of Sleep Medicine (AASM) published a revised form of the International Classification of Sleep Disorders (ICSD-2). Goals of the ICSD-2 are: A) To describe all currently recognized sleep and arousal disorders, and to base the descriptions on scientific and clinical evidence. B) To present the sleep and arousal disorders in an overall structure that is rational and scientifically valid. C) To render the sleep and arousal disorders as compatible with ICD-9 and ICD-10 as possible. In this article, sleep-disordered breathing disorders, as classified in the ICSD-2 are presented.

[Long-term compliance of cpap-therapy--update, predictors and interventions]. / Langzeit-Compliance der CPAP-Therapie--aktueller Stand, Prädiktoren und Interventionsmöglichkeiten.

CPAP (continuous positive airway pressure) is the therapy of choice for obstructive sleep apnea syndrome (OSAS). About 70 % of patients on CPAP use their device for at least 70 % of nights with an application-time of at least 4 hours per night. Severity of breathing disorder respectively disturbance of sleep architecture, degree of daytime sleepiness and patients' satisfaction with diagnostic and therapeutic procedures are good predictors of long-term CPAP-compliance. CPAP-compliance can be increased by intensive patient education. Alternative devices like for example Bilevel or auto-CPAP respectively cannot augment CPAP compliance.