Breathing In Heart Failure Patients Research Articles

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.

Sleep-disordered breathing in heart failure patients after ventricular assist device implantation and heart transplantation.

Chronic heart failure (CHF) represents a major health and economic burden and is associated with high rates of hospital admission, morbidity, mortality and decreased quality-adjusted life years. New advances in the treatment of CHF such as ventricular assist devices (VADs) and heart transplantation have helped improve outcomes. Sleep-disordered breathing (SDB) is highly prevalent in CHF patients and the associated morbidity makes it essential for physicians to be more cognizant about its existence, interaction and need for treatment. This is a review of what is known to date about SDB in CHF patients who have undergone advanced treatments with VADs and/or heart transplantation.

A Practical Approach to the Identification and Management of Sleep-Disordered Breathing in Heart Failure Patients.

Sleep-disordered breathing (SDB) is a major health problem affecting much of the general population. Although SDB is responsible for rapid progression of heart failure (HF) and the worsening morbidity and mortality, advanced HF state is associated with accelerated development of SDB. In the face of recent developments in SDB treatment and availability of effective therapeutic options known to improve quality of life, exercise tolerance, and heart function, most HF patients with SDB are left unrecognized and untreated. This article provides an overview of SDB in HF with focus on practical approaches intended to facilitate screening and treatment.

Improved Accuracy of Automated Estimation of Cardiac Output Using Circulation Time in Patients with Heart Failure

BackgroundLung-to-finger circulation time of oxygenated blood during nocturnal periodic breathing in heart failure patients measured using polysomnography correlates negatively with cardiac function but possesses limited accuracy for cardiac output (CO) estimation. Methods and ResultsCO was recalculated from lung-to-finger circulation time using a multivariable linear model with information on age and average overnight heart rate in 25 patients who underwent evaluation of heart failure. The multivariable model decreased the percentage error to 22.3% relative to invasive CO measured during cardiac catheterization. ConclusionsThis improved automated noninvasive CO estimation using multiple variables meets a recently proposed performance criterion for clinical acceptability of noninvasive CO estimation, and compares very favorably with other available methods.

Beneficial Effects of Positive Airway Pressure Therapy for Sleep-Disordered Breathing in Heart Failure Patients with Preserved Left Ventricular Ejection Fraction

Beneficial Effects of Positive Airway Pressure Therapy for Sleep-Disordered Breathing in Heart Failure Patients with Preserved Left Ventricular Ejection Fraction

19 Sleep-disordered breathing in heart failure patients requiring cardiac resynchronisation therapy: is there a link to poorer outcomes after device insertion

Rationale We sought to ascertain the burden of undiagnosed sleep-disordered breathing (SDB) in high-risk heart failure patients, namely patients requiring cardiac resynchronisation therapy (CRT). Additionally, we looked for correlation between presence of SDB and change in cardiac function pre- and post-device. Methods From a population of 40 patients with CRT devices implanted, a stable group of 18 were selected. Polysomnography was undertaken in each case. Apnoea-hypopnoea index (AHI), oxygen desaturation index (ODI), sleep efficiency, minimum oxygen saturation and snore index were calculated. Comparison was made to left ventricular function, left atrial dimension and mitral regurgitation severity pre- and post-implantation of CRT device. We also measured functional capacity of each patient using the International Physical Activity Questionnaire (IPAQ) tool and compared sleep profiled of those with a good functional capacity (>1000 MET minutes/week) against those with poor functional capacity. Data were analysed with simple descriptive statistics for baseline characteristics and comparisons made using Student t-test. Results Our population had a high AHI (mean 14.2) and ODI (15.2) with poor sleep efficiency (mean 62%). 2 patients (11%) were classified as severe OSA (AHI > 30), and 11 (61%) had mild to moderate OSA. Patients were subdivided into those with improved cardiac function post-implant (n = 8) and those with unchanged or disimproved function (n = 10). Those patients who had an objective improvement in cardiac function by echocardiographic parameters were found to have a better overall sleep profile with a lower AHI (6.8 vs 16.05), snore index (32.6 vs 49.95) and higher sleep efficiency (63% vs 61%) and minimum nocturnal oxygen saturation (88% vs 83%). Patients with poor functional capacity as identified by were additionally found to have a higher snore index (48.7 vs 26.9) and poorer sleep efficiency (48.7 vs 71.8). Conclusions There is a high prevalence of SDB in our cohort with a trend towards more severe sleep apnoea in non-responders to CRT. Failure to respond to appropriate device therapy in severe heart failure may be a red flag for clinicians, with identification and treatment of co-morbid sleep apnoea potentially having a role in optimising patient outcomes.

Beneficial Effects of Positive Airway Pressure Therapy for Sleep-Disordered Breathing in Heart Failure Patients With Preserved Left Ventricular Ejection Fraction.

Right-heart dysfunction is associated with poor prognosis in heart failure with preserved left ventricular ejection fraction (HFpEF). It remains unclear whether sleep-disordered breathing (SDB) treatment using positive airway pressure (PAP) improves right-heart and pulmonary function and exercise capacity and reduces mortality rates of HFpEF patients. PAP may improve right-heart and pulmonary function, exercise capacity and prognosis in HFpEF patients with SDB. One hundred nine consecutive patients with HFpEF (left ventricular ejection fraction >50%) and moderate to severe SDB (apnea-hypopnea index ≥15/h) treated with medications were divided into 2 groups: 31 patients with PAP (PAP group) and 78 patients without PAP (non-PAP group). Right ventricular fractional area change (RV-FAC), tricuspid valve regurgitation pressure gradient (TR-PG), tricuspid valve E/E', forced expiratory volume in 1 second/forced vital capacity (FEV1 /FVC), percentage of vital capacity, and peak VO2 were determined before and 6 months later, and all-cause mortality was followed up for 916 days. All parameters improved in the PAP group (RV-FAC, 36.0% -46.5%; TR-PG, 31.1 mm Hg-22.4 mm Hg; tricuspid valve E/E', 7.8-5.1; FEV1 /FVC, 83.9%-89.8%; percentage of vital capacity, 83.5%-89.9%; and peak VO2 , 16.6 mL/kg/min-19.6 mL/kg/min; P <0.05, respectively) but not in the non-PAP group. Importantly, all-cause mortality was significantly lower in the PAP group than in the non-PAP group (0% vs 12.8%; log-rank P = 0.014). Positive airway pressure improves right-heart and pulmonary function and exercise capacity and may reduce all-cause mortality in patients with HFpEF and SDB.

Abstract 9391: Cyclic Variation of Heart Rate Score by Holter ECG for screening Sleep Disordered Breathing in Heart Failure Patients

Background: Sleep disordered breathing (SDB) has a critical association with cardiovascular mortality and morbidity, especially in patients with heart failure (HF). However, because of the complexity to refer the polysomnography, the majority of SDB patients remain undiagnosed. On the other hand, the abnormality of heart rate variability has been reported in patients with SDB. To explore an efficient ECG-based screening tool for SDB, we examined the usefulness of cyclic variation of heart rate score (CVHRS) by Holter ECG in HF patients. Methods and Results: In this study, 110 patients with HF (mean age 58.6 years, body mass index 23.6, left ventricular ejection fraction 45.5%) were enrolled. The exclusion criteria were the presence of atrial fibrillation and receiving implantable pacemaker device therapy. We simultaneously performed Holter ECG and polysomnography in night time, and measured apnea-hypopnea index (AHI) and CVHRS. We determined the temporal position of the individual dips comprising the CVHRS, using time-domain methods. CVHRS was measured as cyclic and auto correlated dips in smoothed interbeat interval time series. There were 77 patients with mild to moderate SDB (5≤AHI&lt;30/h) and 26 patients with severe SDB (AHI ≥30/h). There was a significant positive correlation between CVHRS and AHI (R=0.60, P&lt;0.001). From the ROC analysis, CVHRS (a cut off value of 30) identified severe SDB with sensitivity 82%, specificity 77%, positive predictive value (PPV) 78%, negative predictive value (NPV) 81% and area under the curve (AUC) 0.83. Conclusions: CVHRS determined by Holter ECG is a useful screening index for severe SDB in HF patients.

Can cardiorespiratory polygraphy replace portable polysomnography in the assessment of sleep-disordered breathing in heart failure patients?

Portable polysomnography (PSG) and cardiorespiratory polygraphy are increasingly being used in the assessment of sleep-disordered breathing (SDB) in heart failure patients. Scoring of SDB from cardiorespiratory polygraphy recordings is based only on respiratory signals, while electroencephalographic, electrooculographic and electromyographic channels are taken into account when using PSG recordings. The aim of this study was to assess the agreement between these two scoring methods. An overnight sleep study was performed in 67 heart failure patients using a standard portable polysomnograph. Each recording was scored twice, once using all acquired signals (PSG mode) and, after a median of 64 days, using only respiratory signals (cardiorespiratory mode). Agreement was assessed by Bland-Altman analysis and Cohen's kappa. We found that (1) more respiratory events were detected using cardiorespiratory analysis [median (25th percentile, 75th percentile), 75 (39, 200) events] compared to analysis of portable PSG [69 (29, 173) events, p < 0.0001], the extra events being, for the vast majority, central in origin; (2) the apnea/hypopnea index (AHI) estimated by cardiorespiratory polygraphy [11.9 (5.7, 30.8)/h] showed a negligible negative bias relative to portable PSG [15.1 (5.7, 33.6)/h; bias, -0.8 (-2.9, 0.4)/h, p = 0.0002]; (3) limits of agreement between the two systems (-6.2/h, 1.7/h) were much smaller than those previously observed between two nights using the same scoring modality; and (4) the kappa coefficient using categorised AHI was 0.89 (95% confidence interval (CI) 0.82, 0.96). We found a high degree of agreement between the AHIs obtained from the two scoring methods, thus suggesting that cardiorespiratory polygraphy may be used as an alternative to portable PSG in the assessment of SDB in heart failure patients.

Utility of Cyclic Variation of Heart Rate Score by Holter ECG for Screening Sleep Disordered Breathing in Heart Failure Patients

Sleep disordered breathing (SDB) has a critical association with cardiovascular mortality and morbidity, especially in patients with heart failure (HF). However, because of the complexity to refer the polysomnography, the majority of SDB patients remain undiagnosed. On the other hand, the abnormality of heart rate variability has been reported in patients with SDB. To explore an efficient ECG-based screening tool for SDB, we examined the usefulness of cyclic variation of heart rate score (CVHRS) by Holter ECG in HF patients.

Sleep Disordered Breathing in Heart Failure Patients with Reduced versus Preserved Ejection Fraction

This study aimed to investigate and compare prevalence of sleep disordered breathing (SDB) in Japanese patients with heart failure with reduced ejection fraction (HFrEF) versus those with HF with preserved EF (HFpEF). This study consecutively included 101 Japanese patients (77 males) with de novo CHF. Echocardiography was performed twice, on admission and at discharge. All patients underwent portable overnight polygraphy within one week before discharge. The patients were stratified into two groups based on LVEF on admission, HFrEF (R group; LVEF<50%, n=82) or HFpEF (P group; LVEF≧50%, n=19); the prevalence of SDB and sleep study data were assessed. When patients with the apnea hypopnea index ≥15 were defined as having SDB, 50% of the study patients had SDB (OSA, 10%; CSA, 39%; MSA, 1%). No significant differences in the prevalence of SDB or sleep data as well as RVSP, E/e' or plasma brain natriuretic peptide (BNP) were found between the two groups. SDB was identified in 50% of de novo Japanese HF patients. When E/e', RVSP and plasma BNP did not significantly differ between the two groups, the prevalence of SDB was similar regardless of LVEF.

Evaluation of upper airway patency during Cheyne–Stokes breathing in heart failure patients

Little is known about the changes in upper airway calibre in Cheyne-Stokes respiration (CSR) during sleep in patients with congestive heart failure. This study aimed to test the hypothesis that upper airway closure occurs during central CSR events, by assessing upper airway calibre during sleep using the forced oscillation technique (FOT). Nine males with compensated heart failure (left ventricular ejection fraction mean ± sem 27.9 ± 5.1%) and predominant central CSR (apnoea/hypopnoea index 43.9 ± 4.2 events · h(-1)) were studied during overnight polysomnography, which included pneumotachography, inductance plethysmography or oesophageal pressure and FOT-derived impedance signal (|Z|). Baseline |Z| values during stable breathing in stage 2 sleep were 11.0 ± 1.3 cmH(2)O · s · L(-1). Mean |Z| increased to 31.9 ± 6.7 cmH(2)O · s · L(-1) during obstructive apnoeas (7% of events, n = 46). Increases in |Z| consistent with upper airway narrowing (more than two-fold baseline) were common during central apnoeas (50 ± 12% of events) occurring in the middle or end of apnoeas and occurred during some central hypopnoeas (16 ± 10% of events), typically in the expiratory phase. These findings indicate that in heart failure patients, reductions in upper airway calibre are common during CSR apnoeas, and may also occur during central hypopnoeas.

Treatment for sleep disordered breathing in heart failure patients

Treatment for sleep disordered breathing in heart failure patients

Influence of cardiomegaly on disordered breathing during exercise in chronic heart failure

Heart failure (HF) patients breathe with a rapid shallow pattern during exercise. This study examined the relationship between cardiac size and tachypnoeic breathing in HF patients during exercise. Thirty-seven HF patients [age = 55 ± 13 years, ejection fraction (EF) = 27 ± 10%, New York Heart Association (NYHA) class = 2.3 ± 1.2] and 42 controls (CTL) (age = 56 ± 14 years, EF = 63 ± 8%) were recruited. Participants underwent maximal exercise testing, pulmonary function testing, and chest radiography for calculation of total thoracic cavity volume (TTCV), diaphragm, heart, and lung volumes. Heart failure patients were divided into two groups: Group A = cardiac volume < median (n = 18) and Group B = cardiac volume ≥ median of the HF patients (n = 19). There was no difference between groups for TTCV (CTL = 8203 ± 1489 vs. Group A = 8694 ± 1249 vs. Group B = 8195 ± 1823 cm(3)). Cardiac volume was different between groups for both absolute (CTL = 630 ± 181 vs. Group A = 894 ± 186 vs. Group B = 1401 ± 382 cm(3), P< 0.001 for all comparisons) and %TTCV (CTL = 8 ± 2 vs. Group A = 10 ± 1 vs. Group A = 18 ± 5%, P< 0.001 for all comparisons). Similarly, total lung volume as a %TTCV was significantly different among the groups (CTL = 70 ± 4 vs. Group A = 65 ± 5 vs. Group A = 58 ± 7%, P< 0.01 for all comparisons). In HF patients, there was a trend (P = 0.10) towards an independent association between cardiac size and tidal volume (V(T)) at 75% of VO(2) peak whereas this relationship was statistically significant at VO(2) peak (P = 0.02) as patients with larger cardiac size had reduced V(T). This study demonstrates the close relationship between cardiac size and breathing pattern during exercise in HF patients. These results suggest cardiac size may pose a significant constraint on the lungs during exercise and may contribute to tachypnoeic breathing.

Atrial Fibrillation Was Associated with Sleep-Disordered Breathing in Heart Failure Patients

Background: Sleep-disordered breathing (SDB) is frequently observed in heart failure patients. Central sleep apnea and Cheyne-Stokes respiration (CSR) have been reported predictors of mortality in systolic heart failure patients. However, little is known about association between atrial fibrillation and SDB in heart failure patients among Japanese population. Methods: Consecutive patients (n=45) with congestive heart failure admitted to our hospital between June 2009 and August 2010 were enrolled. SDB examination was performed using portable monitoring and polysomnography immediately before discharge after stabilizing heart failure by optimal pharmacological therapy. Those patients were classified into two groups according to apnea hypopnea index (AHI): L group (AHI 15). Clinical characteristics were compared between the groups. Results: Twenty-three (51%) patients were classified into L group (AHI=6.9±4.6) and 22 (49%) patients into H group (AHI=33.0±12.6). There was no significant difference in age, body mass index, medication (β-blocker, angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker, spironolactone), cardiac function and eGFR between the groups. Prevalence of atrial fibrillation (33% vs. 16%, p=0.025) and CSR (47% vs. 2%, p<0.001) and plasma BNP level (480±443 pg/ml vs. 246±262 pg/ml, p=0.035) were significantly higher in H than in L group. Conclusions: Japanese heart failure patients with SDB had higher prevalence of atrial fibrillation and CSR and higher plasma BNP level compared with the patients without SDB.

Prediction of Death and Hospital Admissions Via Innovative Detection of Cheyne-Stokes Breathing in Heart Failure Patients

Cheyne-Stokes breathing (CSB) has been associated with advanced heart failure for two centuries. However, the current conventional method of CSB detection is via a full-night polysomnographic test which is a complex, expensive and inconvenient for the patients. Accordingly, the purpose of the current study was to assess a more practical method for CSB detection in heart failure (HF) patients and investigate its prognostic applications. We describe here risk stratification for mortality and morbidity over 6 months of follow-up by using standard pulse oximeter analyzed with an innovative automated program for CSB detection. A total of 109 consecutive HF out-patients, 93 men and 16 women underwent a full-night sleep studies performed at home, using a standard pulse oximeter for detection of CSB during sleep. Data was analyzed by an innovative algorithm-based system. Of the 109 patients, our analysis identified 46 (42%) patients with episodes of CSB. Within the 6-month follow-up period, 8 (17.4%) of these patients died or were urgently transplanted, and 14 (30.4%) were hospitalized for HF. Multiple regression testing with several known prognostic parameters, showed that CSB was the most significant predictor of mortality or heart failure hospitalizations (p < 0.001). Heart failure patients with CSB have increased mortality and morbidity over the next 6 months. The detection of CSB is feasible via a simple and reliable method using a standard pulse oximeter, which may be more suitable for sick HF patients than the complex and inconvenient full-night polysomnography.

Fluctuations of the fractal dimension of the electroencephalogram during periodic breathing in heart failure patients

The physiological mechanisms responsible for periodic breathing (PB) in heart failure (HF) patients are still debated. A role for rhythmic shifts in the level of wakefulness has been suggested, but their existence has never been proven. In this study we investigated the existence of an oscillation in EEG activity during PB in these patients and assessed its relationship with the ventilatory oscillation. EEG activity was measured by the fractal dimension (FD) and by a spectral technique (weighted mean frequency, WMF) in 17 stable HF patients (mean age +/- SD: 57+/-10 yrs, NYHA class: 2.6 +/- 0.4, LVEF: 24 +/- 6%), with sustained PB during supine rest. The relationship between minute ventilation (MV) signal and FD and WMF was assessed by coherence analysis. Most patients (10/17) showed a well defined oscillation in FD and WMF at the frequency of PB closely linked (coherence > 0.7) with the oscillation of MV. In the remaining patients, neither FD nor WMF showed a clear oscillatory pattern synchronous with MV. Overall, the two EEG-derived parameters showed the same coherence with the ventilatory oscillation (mean coherence +/- SD: 0.65 +/- 0.25 vs 0.66 +/- 0.23, for FD and WMF respectively, p = 0.44). Our results provide evidence that during PB in HF patients, EEG activity often, but not always, fluctuates synchronously with the ventilatory oscillation. These fluctuations can be effectively detected by the fractal dimension, but classical spectral methods provide substantially the same information. Other mechanisms, particularly chemical instability in the respiratory control system, are likely to play a role in the genesis of PB.

Pathophysiological and clinical relevance of simplified monitoring of nocturnal breathing disorders in heart failure patients

Nocturnal breathing disorders in the form of periodic breathing (PB) are very common in heart failure (HF) patients. There is an increasing interest in simple and affordable tools to screen patients and monitor these disorders at home on a long-term basis. We aimed to assess the pathophysiological and clinical relevance of a simplified method for monitoring of PB suitable to be self-managed by the patient at home. A night-time respiratory recording was performed in 397 optimally treated HF patients (age 60 +/- 11 years, NYHA class 2.4 +/- 0.6, left ventricular ejection fraction 29 +/- 7%) and the duration of PB (PB(Dur)) automatically computed. Patients were followed-up for 1 year and the prognostic value of PB(Dur) evaluated. In 45 patients, we assessed the association between PB(Dur) and severity of oxygen desaturations (number of desaturations >3%). Twenty six of the 397 patients died of cardiac causes. A PB(Dur) > or =2 h was significantly associated with an increased risk of cardiac death after adjustment for major clinical predictors [hazard ratio (95% CI): 3.5 (1.6-7.9), P = 0.002]. The correlation between PB(Dur) and severity of desaturations was 0.94 (P < 0.0001). Relevant pathophysiological and clinical information can be obtained from simplified monitoring of breathing disorders managed by the patient. These results provide new perspectives in the investigation of the clinical impact of abnormal breathing in HF patients.

Periodic breathing in heart failure patients: testing the hypothesis of instability of the chemoreflex loop.

In this study, we applied time- and frequency-domain signal processing techniques to the analysis of respiratory and arterial O(2) saturation (Sa(O(2))) oscillations during nonapneic periodic breathing (PB) in 37 supine awake chronic heart failure patients. O(2) was administered to eight of them at 3 l/min. Instantaneous tidal volume and instantaneous minute ventilation (IMV) signals were obtained from the lung volume signal. The main objectives were to verify 1) whether the timing relationship between IMV and Sa(O(2)) was consistent with modeling predictions derived from the instability hypothesis of PB and 2) whether O(2) administration, by decreasing loop gain and increasing O(2) stores, would have increased system stability reducing or abolishing the ventilatory oscillation. PB was centered around 0.021 Hz, whereas respiratory rate was centered around 0.33 Hz and was almost stable between hyperventilation and hypopnea. The average phase shift between IMV and Sa(O(2)) at the PB frequency was 205 degrees (95% confidence interval 198-212 degrees). In 12 of 37 patients in whom we measured the pure circulatory delay, the predicted lung-to-ear delay was 28.8 +/- 5.2 s and the corresponding observed delay was 30.9 +/- 8.8 s (P = 0.13). In seven of eight patients, O(2) administration abolished PB (in the eighth patient, Sa(O(2)) did not increase). These results show a remarkable consistency between theoretical expectations derived from the instability hypothesis and experimental observations and clearly indicate that a condition of loss of stability in the chemical feedback control of ventilation might play a determinant role in the genesis of PB in awake chronic heart failure patients.