The effect of successful heart transplant treatment of heart failure on central sleep apnea

STUDY OBJECTIVE: Central sleep apnea (CSA) associated with Cheyne-Stokes respiration in patients with congestive heart failure (CHF) is thought to be an acquired pattern of respiratory control instability related, at least in part, to elevated sympathetic nervous system activity. The effect of restoring heart function to normal with heart transplantation in patients with CHF and CSA has only been reported within weeks of the transplant and with varying results. The purpose of the study was to evaluate the impact of successful heart transplant on sympathetic nervous system activity and CSA severity in patients with CHF. DESIGN: Controlled prospective trial. SETTING: University hospital. PATIENTS: Twenty-two patients with CHF (13 patients with CSA, and 9 patients with no sleep-disordered breathing [SDB]). INTERVENTIONS AND MEASUREMENTS: Polysomnography, left ventricular ejection fraction (LVEF), and overnight urinary norepinephrine excretion (UNE) were measured before and > 6 months after successful heart transplantation. RESULTS: In the CSA group, there was a fall in apnea-hypopnea index (AHI) [mean +/- SD, 28 +/- 15 to 7 +/- 6/h; p < 0.001] and UNE (48.1 +/- 30.9 to 6.1 +/- 4.8 nmol/mmol creatinine, p < 0.001) associated with normalization of LVEF (19.2 +/- 9.3% to 53.7 +/- 6.1%, p < 0.001) at 13.2 +/- 8.3 months following heart transplantation. Of the CSA group following transplantation, seven patients had no SDB (AHI < 5/h), three patients had persistent CSA (AHI, 12.3 +/- 0.9/h) and four patients acquired obstructive sleep apnea (OSA) [AHI, 11.2 +/- 7.4/h]. In comparison, none of the control group acquired CSA or OSA after transplantation. CONCLUSIONS: We conclude that CSA may persist despite normalization of heart function and sympathetic nerve activity.     

Sleep-disordered breathing in patients with symptomatic heart failure: a contemporary study of prevalence in and characteristics of 700 patients

AIM: Evaluation of the prevalence and nature of sleep-disordered breathing (SDB) in patients with symptomatic chronic heart failure (CHF) receiving therapy according to current guidelines. METHODS AND RESULTS: We prospectively screened 700 patients with CHF (NYHA class> or =II, LV-EF< or =40%) for SDB using cardiorespiratory polygraphy (Embletta). Furthermore, echocardiography, cardiopulmonary exercise and 6-min walk testing were performed. Medication included ACE-inhibitors and/or AT1-receptor blockers in at least 94%, diuretics in 87%, beta-blockers in 85%, digitalis in 61% and spironolactone in 62% of patients. SDB was present in 76% of patients (40% central (CSA), 36% obstructive sleep apnoea (OSA)). CSA patients were more symptomatic (NYHA class 2.9+/-0.5 vs. no SDB 2.57+/-0.5 or OSA 2.57+/-0.5; p<0.05) and had a lower LV-EF (27.4+/-6.6% vs. 29.3+/-2.6%, p<0.05) than OSA patients. Oxygen uptake (VO(2)) was lowest in CSA patients: predicted peak VO(2) 57+/-16% vs. 64+/-18% in OSA and 63+/-17% in no SDB, p<0.05. 6-min walking distances were 331+/-111 m in CSA, 373+/-108 m in OSA and 377+/-118 m in no SDB (p<0.05). CONCLUSIONS: This study confirms the high prevalence of SDB, particularly CSA in CHF patients. CSA seems to be a marker of heart failure severity.     

Incidence of sleep-disordered breathing in patients with hypertrophic cardiomyopathy

The authors investigated the prevalence of sleep-disordered breathing (SDB) together with its clinical correlations in patients with hypertrophic cardiomyopathy (HCM). A total of 113 consecutive patients including 63 patients with HCM (40 men; mean age, 59.5±13.0 years; New York Heart Association class, 2.0±0.9) underwent cardiorespiratory polygraphy in addition to their clinical work-up including echocardiography. Patients with an apnea-hypopnea-index (AHI) ≥5/h were considered to have SDB. If thoracic and abdominal inspiration efforts were documented, SDB was considered to be obstructive sleep apnea (OSA), otherwise SDB was considered to be central sleep apnea (CSA). The age- and sex-matched control group of 50 patients had exclusion of coronary artery disease by angiography, and normal left ventricular (ejection fraction ≥55%) and valvular function. SDB was diagnosed in 52 patients (82.5% vs 72% in the control group; P =not significant) with a mean AHI of 23.0±17.8/h. Severity of SDB was higher in patients with HCM than in the control group (AHI 12.2±7.6/h; P =.003). OSA was documented in 39 patients (AHI 21.2±16.5/h) and CSA in 13 (AHI 28.4±20.9/h). The severity of SDB correlated with New York Heart Association functional class (η=0.9, η(2) =0.811) and with left ventricular end-diastolic (r=0.6, P <.01) and left atrial (r=0.4, P <.01) diameter. No correlations were found between SDB and other clinical or echocardiographic parameters. SDB is common in patients with hypertrophic cardiomyopathy, with a predominance of OSA and correlations with markers of left ventricular function.     

Overnight shift from obstructive to central apneas in patients with heart failure: role of PCO2 and circulatory delay

BACKGROUND: Obstructive (OSA) and central sleep apnea (CSA) can coexist in patients with congestive heart failure (CHF). However, the reason why OSA events occur at one time and CSA events at another has not been determined. We hypothesized that a change in PCO(2) would be associated with an alteration in apnea type: a decrease in PCO(2) should lead to CSA. METHODS AND RESULTS: To test this hypothesis, we evaluated minute ventilation (V(I)), transcutaneous PCO(2) (PtcCO(2)), circulation time, and periodic breathing cycle length during overnight polysomnography in 12 patients with CHF and coexisting OSA and CSA. V(I) was significantly greater (mean+/-SEM, 9.4+/-1.3 versus 8.0+/-0.9 L/min; P:<0.05) and PtcCO(2) was lower (39.4+/-1.0 versus 41.9+/-1.1 mm Hg, P:<0.01) during episodes of CSA than of OSA. These changes were associated with significant lengthening of circulation time (23.6+/-3.7 versus 21.1+/-3.6 seconds, P:<0.01) and periodic breathing cycle length (53.7+/-3.5 versus 49.6+/-2.9 seconds, P:<0.01). In addition, the proportion of obstructive events decreased (from 68.5+/-11.4% to 22.5+/-7.2%, P:<0.001) and of CSA events increased (from 31.5+/-11.4% to 77.5+/-7.2%, P:<0.001) from the first to the last quarter of the night in association with a significant decrease in PtcCO(2) (from 42.6+/-0.9 to 40.8+/-0.9 mm Hg, P:<0.01). CONCLUSIONS: In patients with CHF, the shift from OSA to CSA is associated with a reduction in PCO(2). This appears to be related to an overnight deterioration in cardiac function as suggested by the concurrent lengthening of circulation time. Therefore, in CHF patients, alterations in cardiac function may influence apnea type.     

Risk factors for central and obstructive sleep apnea in 450 men and women with congestive heart failure.

In previous analyses of the occurrence of central (CSA) and obstructive sleep apnea (OSA) in patients with congestive heart failure (CHF), only men were studied and risk factors for these disorders were not well characterized. We therefore analyzed risk factors for CSA and OSA in 450 consecutive patients with CHF (382 male, 68 female) referred to our sleep laboratory. Risk factors for CSA were male gender (odds ratio [OR] 3.50; 95% confidence interval [CI], 1.39 to 8.84), atrial fibrillation (OR 4.13; 95% CI 1.53 to 11. 14), age > 60 yr (OR 2.37; 95% CI 1.35 to 4.15), and hypocapnia (PCO(2 )< 38 mm Hg during wakefulness) (OR 4.33; 95% CI 2.50 to 7. 52). Risk factors for OSA differed by gender: in men, only body mass index (BMI) was significantly associated with OSA (OR for a BMI > 35 kg/m(2), 6.10; 95% CI 2.86 to 13.00); whereas, in women, age was the only important risk factor (OR for age > 60 yr, 6.04; 95% CI 1.75 to 20.0). We conclude that historical information, supplemented by a few simple laboratory tests may enable physicians to risk stratify CHF patients for the presence of CSA or OSA, and the need for diagnostic polysomnography for such patients. Sin DD, Fitzgerald F, Parker JD, Newton G, Floras JS, Bradley TD. Risk factors for central and obstructive sleep apnea in 450 men and women with congestive heart failure.     

Effects of nocturnal oxygen therapy on outcome measures in patients with chronic heart failure and cheyne-stokes respiration.

BACKGROUND: The effects of nasal oxygen (O(2)) supply at night using conventional home oxygen therapy (HOT) equipment on quality of life (QOL) and sleep-disordered breathing (SDB) were evaluated in patients with congestive heart failure (CHF). Nasal nocturnal O(2) therapy not only stabilizes SDB but also reduces sympathetic activity, and improves exercise capacity in patients with CHF. However, the effects of oxygen on the cardiac function and QOL of heart failure patients have not been fully elucidated. METHODS AND RESULTS: Fifty-six patients with CHF (New York Heart Association class II - III, left ventricular ejection fraction (LVEF) 相似文献   

A high prevalence of sleep disordered breathing in men with mild symptomatic chronic heart failure due to left ventricular systolic dysfunction

BACKGROUND: Sleep disordered breathing (SDB) is common in severe chronic heart failure (CHF) and is associated with increased morbidity and mortality. The prevalence of SDB in mild symptomatic CHF is unknown. AIM: The aim of this study was to determine the prevalence and characteristics of SDB in male patients with NYHA class II symptoms of CHF. METHODS AND RESULTS: 55 male patients with mild symptomatic CHF underwent assessment of quality of life, echocardiography, cardiopulmonary exercise, chemoreflex testing and polysomnography. 53% of the patients had SDB. 38% had central sleep apnoea (CSA) and 15% had obstructive sleep apnoea. SDB patients had steeper VE/VCO(2) slope [median (inter-quartile range) 31.1 (28-37) vs. 28.1 (27-30) respectively; p=0.04], enhanced chemoreflexes to carbon dioxide during wakefulness [mean+/-sd: 2.4+/-1.6 vs. 1.5+/-0.7 %VE Max/mmHg CO(2) respectively; p=0.03], and significantly higher levels of brain natriuretic peptide and endothelin-1 compared to patients without SDB. No differences in left ventricular ejection fraction, percent predicted peak oxygen uptake, or symptoms of SDB were observed. CONCLUSIONS: A high prevalence of SDB was found in men with mild symptomatic CHF. Patients with SDB could not be differentiated by symptoms or by routine cardiac assessment making clinical diagnosis of SDB in CHF difficult.     

Washout Rate of Cardiac Iodine-123 Metaiodobenzylguanidine is High in Chronic Heart Failure Patients With Central Sleep Apnea

BackgroundThe association between sleep-disordered breathing (SDB) assessed by polysomnography and cardiac sympathetic nerve activity (SNA) assessed by cardiac iodine-123 metaiodobenzylguanidine (123I-MIBG) imaging has not been investigated in patients with chronic heart failure (CHF).Methods and ResultsWe performed cardiac 123I-MIBG scintigraphy and overnight polysomnography in 59 patients with stable CHF. The patients were classified into the 3 groups: 19 with no or mild SDB (NM-SDB, apnea-hypopnea index <15); 21 with central sleep apnea (CSA), and 19 with obstructive sleep apnea (OSA). The cardiac washout rate (WR) of 123I-MIBG was obtained from initial and delayed planar 123I-MIBG images. The WR was higher in patients with CSA (54.2 ± 11.6%) than in those with OSA (37.9 ± 8.6%, P < .05) or NM-SDB (40.8 ± 8.8%, P < .05). The WR correlated positively with central apnea index (ρ = 0.40, P = .002). A stepwise multiple regression analysis selected CSA and plasma brain natriuretic peptide levels as independent variables associated with the WR.ConclusionsThe WR was higher in CHF patients with CSA than in those with OSA or NM-SDB, and CSA was independently associated with the WR, suggesting a link of CSA to increased cardiac SNA in CHF.     

Influence of cardiac resynchronisation therapy on different types of sleep disordered breathing

AIMS: This study investigates the influence of cardiac resynchronisation therapy (CRT) on sleep disordered breathing (SDB) in patients with severe heart failure (HF). METHODS AND RESULTS: Seventy-seven patients with HF (19 females; 62.6+/-10 years) eligible for CRT were screened for presence, type, and severity of SDB before and after CRT initiation (5.3+/-3 months) using cardiorespiratory polygraphy. NYHA class, frequency of nycturia, cardiopulmonary exercise, 6-minute walking test results, and echocardiography parameters were obtained at baseline and follow-up. Central sleep apnoea (CSA) was documented in 36 (47%), obstructive sleep apnoea (OSA) in 26 (34%), and no SDB in 15 (19%) patients. CRT improved clinical and haemodynamic parameters. SDB parameters improved in CSA patients only (apnoea hypopnoea index: 31.2+/-15.5 to 17.3+/-13.7/h, p<0.001; SaO2min: 81.8+/-6.6 to 84.8+/-3.3%, p=0.02, desaturation: 6.5+/-2.3 to 5.5+/-0.8%, p=0.004). Daytime capillary pCO2 was significantly lower in CSA patients compared to those without SDB with a trend towards increase with CRT (35.5+/-4.2 to 37.9+/-5.7 mm Hg, ns). After classifying short term clinical and haemodynamic CRT effects, improved SDB parameters in CSA occurred in responders only. CONCLUSIONS: In patients with severe HF eligible for CRT, CSA is common and can be influenced by CRT, this improvement depends on good clinical and haemodynamic response to CRT.     

Temporal worsening of sleep-disordered breathing in the acute phase of myocardial infarction.

BACKGROUND: Sleep apnea is an important risk factor for cardiovascular diseases, but whether the severity of sleep-disordered breathing (SDB) changes in the acute phase of myocardial infarction (MI) has not been well determined, nor has it been determined what type of SDB, central or obstructive, (CSA or OSA) is exacerbated. METHODS AND RESULTS: Polysomnography was performed in patients with acute phase of MI during the acute (days 3-5) and chronic (day 14) phases. On the same day, the ventilatory equivalent (VE)/carbon dioxide production (VCO(2)) slope, urinary catecholamines secretion and arterial carbon dioxide tension were assessed before sleep. The apnea/hypopnea index was significantly decreased in the chronic phase (13.26+/-11.30 vs 6.97+/-5.67, p<0.05). The distribution of the types of SDB was unchanged, indicating both CSA and OSA can be exacerbated in the acute phase of MI. The VE/VCO(2) slope and arterial carbon dioxide tension before sleep were also unchanged. Urinary norepinephrine secretion was slightly decreased, although the difference was not significant. CONCLUSIONS: SDB is temporarily worsened in the acute phase of AMI and both CSA and OSA are worsened in AMI.     

Sleep-disordered breathing and inappropriate defibrillator shocks in chronic heart failure

Purpose

Supraventricular tachyarrhythmias are a major cause of inappropriate defibrillator shocks. Sleep-disordered breathing (SDB) is a known risk factor for atrial fibrillation (AF). We hypothesized that Cheyne–Stokes respiration (CSA) and obstructive sleep apnea (OSA) have an impact on inappropriate defibrillator discharges in patients witch chronic heart failure (CHF) and cardiac resynchronization therapy with defibrillator (CRT-D).

Methods

In this study, 172 patients with CHF (LVEF ≤?45?%, NYHA-class ≥?2) and CRT-D underwent overnight polygraphy; 54 had no SDB (apnea–hypopnea index Results In all, 17 patients had inappropriate defibrillator shocks (9.9?%; eight oversensing due to lead fractures, five caused by atrial fibrillation, four because of sinus tachycardia). Mean event-free survival time was 33.5?±?1.2 months in the CSA group, 35.2?±?0.7 months in the OSA group, and 32.1?±?1.5 months in the no SDB group, respectively (CSA vs. no SDB p?=?0.63; OSA vs. no SDB p?=?0.31; CSA vs. OSA p?=?0.45). Stepwise Cox proportional hazard regression analysis revealed an independent association for age (per year: hazard ratio 0.90, 95?% confidence interval 0.85–0.96, p?Conclusions SDB was not associated with inappropriate defibrillator shocks. We assume this is due to the low incidenceand low proportion of inappropriate therapies in response to AF.     

Impact of sleep apnea on sympathetic nervous system activity in heart failure

OBJECTIVES: To compare and establish the relevance of the relative degree of sympathetic nervous system activity (SNSA) in groups of patients with congestive heart failure (CHF) and obstructive sleep apnea (OSA), and in a control group. BACKGROUND: Elevated SNSA is a characteristic feature of CHF, as well as of OSA and nonhypercapnic central sleep apnea (CSA). OSA and CSA commonly occur with CHF; however, the relative contribution of apnea-related hypoxemia and sleep fragmentation to the SNSA of patients with CHF is not known. METHODS: This was a prospective, controlled, observational trial in which the overnight urinary norepinephrine (UNE) level, which is a measure of integrated overnight SNSA while asleep, was measured in 15 healthy male volunteers, 15 male OSA patients who did not have CHF, and 90 CHF patients (77 men). CHF patients also had right heart pressure measurements and then were grouped by the presence of sleep apnea. RESULTS: Compared with healthy individuals, the mean (+/- SD) UNE level was significantly elevated in the OSA group and was even further elevated in the CHF group (13.4 +/- 5.6 vs 19.7 +/- 12.3 vs 32.2 +/- 20.2 nmol/mmol creatinine, respectively; p < 0.001 [by analysis of variance]). Within the CHF group, the mean UNE levels were greatest in the CHF-CSA group compared with the CHF-OSA group and the CHF nonapnea group (43.9 +/- 24.1 vs 24.0 +/- 10.8 vs 22.4 +/- 8.9 nmol/mmol creatinine, respectively; p < 0.001). Using a multivariate regression model, the variance of the UNE level in the CHF group was predicted, in descending order, by pulmonary capillary wedge pressure (14% variance), rapid eye movement sleep (8%), and the mean sleep pulse oximetry level (7%). CONCLUSIONS: Overnight SNSA is significantly greater in CHF patients than in OSA patients. Moreover, the hemodynamic severity of CHF contributes to the elevation of SNSA in CHF patients to a greater degree than apnea-related hypoxemia.     

Sleep-disordered breathing and epicardial adipose tissue in patients with heart failure

Background and aims

Sleep-disordered breathing (SDB) is common in patients with heart failure (HF), contributes to the progression of cardiac disease, and is associated with adverse prognosis. Previous evidence indicates that epicardial adipose tissue (EAT) is independently associated with sleep apnea in obese individuals. We explored the relationship between SDB and EAT in HF patients.

Effects of dynamic bilevel positive airway pressure support on central sleep apnea in men with heart failure

BACKGROUND: Treatment with continuous positive airway pressure (CPAP) improves cardiac function in chronic heart failure (CHF) patients with central sleep apnea (CSA)-Cheyne-Stokes respiration (CSR) by stabilizing ventilation, but frequently central apneas and hypopneas persist. Our objective was to test the hypothesis that flow-targeted dynamic bilevel positive airway pressure (BPAP) support (BiPAP autoSV; Respironics; Murrysville, PA) effectively suppresses CSR-CSA in CHF patients. METHODS: We studied 14 CHF patients with CSR-CSA (and residual CSA on positive airway pressure therapy) during 3 consecutive nights: (1) diagnostic polysomnography, (2) CPAP (n=10) or BPAP (n=4) titration, and (3) dynamic flow-targeted dynamic BPAP support with an expiratory positive airway pressure (EPAP) set to suppress obstructive respiratory events, and an inspiratory positive airway pressure (IPAP) dynamically ranging between 0 and 15 cm H2O above the EPAP. RESULTS: CPAP or BPAP significantly reduced the apnea-hypopnea index (AHI) [mean+/-SD, 46+/-4 events/h to 22+/-4 events/h; p=0.001] compared to the first night without treatment. Flow-targeted dynamic BPAP support (mean EPAP, 6.5+/-1.7 cm H2O; maximal IPAP, 21.9+/-2.1 cm H2O) further reduced the AHI to 4+/-1/h of sleep compared to the untreated (p<0.001) and CPAP or BPAP night (p=0.002). After the first night of flow-targeted dynamic BPAP support, patients rated on an analog scale (range, 0 to 10) the treatment as comfortable (6.9+/-0.6), and the sleep quality as improved compared to previous nights (7.4+/-0.6). CONCLUSION: Flow-targeted dynamic BPAP support effectively suppresses CSR-CSA in patients with CHF and is well tolerated.     

Sleep‐disordered breathing in heart failure patients with different etiologies

BackgroundThe prevalence of sleep‐disordered breathing (SDB) is closely related to the severity of heart failure (HF), and the severity of HF is different in patients with HF of different etiologies. Hypothesis: This study aimed to explore the prevalence of SDB in patients with HFof different etiologies.MethodsHospitalized HF patients were consecutively enrolled. All patients underwent portable overnight cardiorespiratory polygraphy. Patients were divided into five groups according to the etiology of HF: ischemic, hypertensive, myocardial, valvular, and arrhythmic. The prevalence of SDB and clinical data was compared among the five groups.ResultsIn total, 248 patients were enrolled in this study. The prevalence of SDB in HF was 70.6%, with the prevalence of obstructive sleep apnea (OSA) at 47.6% and central sleep apnea (CSA) at 23.0%. Patients were divided into five groups: ischemic, hypertensive, myocardial, valvular, and arrhythmic. The prevalence of SDB among the five groups was 75.3%, 81.4%, 77.8%, 51.9%, and 58.5% (p = .014), respectively. The prevalence of OSA among the five groups was 42.7%, 72.1%, 36.1%, 37.0%, and 49.1% (p = .009), whereas the CSA was 32.6%, 9.3%, 41.7%, 14.8%, and 9.4% (p < .001), respectively.ConclusionsSDB is common in HF patients. The prevalence and types of SDB varied in HF with different etiologies, which may be related to the different severities of HF. SDB was highly prevalent in patients with ischemic, hypertensive, and myocardial HF. Hypertensive HF patients were mainly complicated with OSA, while myocardial HF patients were mainly complicated with CSA. Both conditions were highly prevalent in ischemic HF patients. The prevalence of SDB was relatively low in valvular and arrhythmic HF patients, and OSA was the main type.     

Cardiac resynchronization therapy improves central sleep apnea and Cheyne-Stokes respiration in patients with chronic heart failure

OBJECTIVES: We studied the effects of cardiac resynchronization therapy (CRT) on heart failure (HF) patients with central sleep apnea (CSA). BACKGROUND: Patients with advanced HF often suffer from CSA with Cheyne-Stokes respiration. Cardiac resynchronization therapy improves myocardial function and exercise capacity in HF patients with conduction disturbances. The relationship between CRT and CSA is currently unknown. METHODS: Twenty-four patients (7 females; 62 +/- 11 years) with HF, a reduced left ventricular ejection fraction (24 +/- 6%), and left bundle branch block (QRS duration 173 +/- 22 ms) received a CRT device. The number of apneas and hypopneas per hour (apnea-hypopnea index [AHI]) and minimal oxygen saturation (SaO2min) were quantified by cardiorespiratory polygraphy. Fourteen patients showed CSA (AHI >5/h), and 10 patients had an AHI <5/h without CSA. Subjective sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). Data were evaluated before and after 17 +/- 7 weeks of CRT. RESULTS: In patients with CSA, CRT led to a significant decrease in AHI (19.2 +/- 10.3 to 4.6 +/- 4.4, p < 0.001) and PSQI (10.4 +/- 1.6 to 3.9 +/- 2.4, p < 0.001) without Cheyne-Stokes respiration and to a significant increase in SaO2min (84 +/- 5% to 89 +/- 2%, p < 0.001). There was no significant change in AHI (1.7 +/- 0.7 to 1.5 +/- 1.6), PSQI (2.4 +/- 0.5 to 2.6 +/- 0.9), and SaO2min (90 +/- 2% to 91 +/- 1%) in patients without CSA. CONCLUSIONS: Cardiac resynchronization therapy leads to a reduction of CSA and to increased sleep quality in patients with HF and sleep-related breathing disorders. This may have prognostic implications in patients receiving CRT.     

First experience of using new adaptive servo-ventilation device for Cheyne-Stokes respiration with central sleep apnea among Japanese patients with congestive heart failure: report of 4 clinical cases.

BACKGROUND: Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) in congestive heart failure (CHF) is generally considered a poor prognostic indicator, but treatment of CSR-CSA using an adaptive servo-ventilation (ASV) device has been developed. This is the first evaluation of its use in the management of CSR-CSA in Japanese CHF patients. METHODS AND RESULTS: Four CHF patients with CSR-CSA that was unresponsive to conventional positive airway pressure (CPAP) underwent 3 nights of polysomnography: baseline, CPAP or bi-level PAP, and on the ASV. The apnea - hypopnea index (AHI) and central-AHI (CAHI) were markedly improved on ASV (AHI 62.7+/-10.1 to 5.9+/-2.2 /h, p=0.0006, CAHI 54.5+/-6.7 to 5.6+/-2.3 /h, p=0.007). In addition, the sleep quality improved significantly on ASV, including arousal index (62.0+/-10.5 to 18.7 +/-6.2 /h, p=0.012), percentage of slow-wave sleep (2.6+/-2.6 to 19.4+/-4.8 %, p=0.042). CONCLUSIONS: ASV markedly improved CSR-CSA in patients with CHF. It is a promising treatment for Japanese patients with CHF.     

Apnea-related heart rate variability in congestive heart failure patients

Sleep-disordered breathing (SDB) causes fluctuation of the RR interval. However, the details are uncertain. We studied the characteristics of sleep-related heart rate variation (HRV) in congestive heart failure (CHF) patients with SDB. Ambulatory electrocardiograms and data on respiration (oronasal flow, trachea sound, abdominal wall movement, and oxygen saturation) were simultaneously recorded by a multi-channel digital recorder for 13 CHF patients (8 men and 5 women; mean age, 68 +/- 4 years). Heart rate variation occurred as a result of cyclical apnea attacks between 0.005 and 0.03 Hz (apnea band). The proportion of the apnea band (% apnea) increased with the number of apnea episodes, and SDB was highly likely when the % apnea was > or = 80%. Low-flow oxygen administration effectively reduced apnea frequency, and the apnea-related HRV also decreased. We concluded that apnea-related HRV was useful for detecting and following SDB in CHF cases.     

Die Rolle der Schlafmedizin bei Herz-Kreislauf-Erkrankungen

Sleep-disordered breathing (SDB) is receiving more attention within the cardiology community. While obstructive sleep apnea (OSA) is thought to be an independent risk factor for the development for and prognosis of various cardiac and cardiovascular diseases, central sleep apnea (CSA) and Cheyne-Stokes respiration (CSR) in particular are thought to be comorbidities with an independent prognostic impact in patients with established cardiovascular diseases. Simplified screening tools enable the cardiologist to easily screen for or at least rule out significant SDB in their patients. Even the diagnosis of OSA or CSA seems to be feasible using multichannel cardiorespiratory polygraphy or polysomnography. In addition, apnea screening is becoming more and more integrated into various cardiac devices, e. g. Holter electrocardiogram (ECG) and implantable cardiac rhythm devices. Modern therapeutic devices using automatic adjustment of positive airway pressure facilitate treatment of patients with SDB and fully implantable respiratory devices using transvenous approaches, e. g. transvenous phrenic nerve stimulation to treat Cheyne-Stokes respiration, might open up a new field in cardiology. Once therapeutic interventions to treat SDB are proven to improve quality of life, cardiovascular function and prognostic outcome in patients with cardiovascular diseases, new pathways to diagnose and treat these patients need to be determined.     

In-hospital Testing for Sleep-disordered Breathing in Hospitalized Patients With Decompensated Heart Failure: Report of Prevalence and Patient Characteristics

BackgroundSleep-disordered breathing (SDB) is present in more than 50% of ambulatory patients with chronic heart failure. The prevalence and type of SDB in hospitalized patients with acutely decompensated heart failure (ADHF) are not known.Methods and ResultsIn-hospital sleep studies were performed on consecutive patients with ADHF who were not previously tested for SDB. A total of 395 consecutive patients with ADHF underwent successful sleep study recording during hospitalization. A total of 298 patients (75%, 95% CI [71–80%] had SDB; of these, 226 (57%, 95% CI [52–62]) had predominantly obstructive SDB and 72 (18%, 95% CI [14–22]) had predominantly central SDB. Only 25% (95% CI 20–29%) of patients were free of SDB. Validation polysomnography between 6 and 8 weeks after discharge on a subgroup of unselected patients with obstructive SDB revealed a 100 % positive predictive value (95% CI 94–100%) for obstructive sleep apnea (OSA).ConclusionsSimilar to stable chronic heart failure, ADHF is associated with a high prevalence of SDB. The prevalence of predominantly obstructive SDB exceeded that of predominantly central SDB in ADHF patients. The presence of obstructive SDB during hospitalization predicted a diagnosis of OSA on polysomnography.