Domiciliary Oxygen Therapy Improves Sub-Maximal Exercise Capacity and Quality of Life in Chronic Heart Failure (original) (raw)
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European Journal of Heart Failure, 2007
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 ≥ II, LV-EF ≤ 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%, β-blockers in 85%, digitalis in 61% and spironolactone in 62% of patients.
Sleep and Exertional Periodic Breathing in Chronic Heart Failure
2000
Background-Sleep and exertional periodic breathing are proverbial in chronic heart failure (CHF), and each alone indicates poor prognosis. Whether these conditions are associated and whether excess risk may be attributed to respiratory disorders in general, rather than specifically during sleep or exercise, is unknown.
Canadian Journal of Cardiology, 2015
Background: Sleep-disordered breathing (SDB) is highly prevalent in patients with chronic heart failure (CHF) and is associated with a poor prognosis. Data on SDB-related symptoms and vigilance impairment in patients with CHF and SDB are rare. Thus, the objective of the present study was to assess a wide spectrum of SDB-related symptoms and objective vigilance testing in patients with CHF with and without SDB. Methods: Patients with CHF (n ¼ 222; average age, 62 years; left ventricular ejection fraction [LVEF], 34%) underwent polysomnography regardless of the presence or absence of SDB-related symptoms. Patients were stratified into those with no SDB (apnea-hypopnea index [AHI] < 15 episodes/h), moderate SDB (AHI ! 15 to < 30 episodes/ h), and severe SDB (AHI ! 30 episodes/h). A standardized institutional questionnaire assessing a wide spectrum of SDB-related symptoms was applied. A subset of patients underwent objective vigilance testing (Quatember Maly, 100 stimuli within 25 minutes). Results: Daytime fatigue (no SDB, moderate SDB, and severe SDB: 53%, 69%, and 80%, respectively; P ¼ 0.005), unintentional sleep (9%, 15%, and 32%, respectively; P ¼ 0.004), and xerostomia (52%, 49%, and 70%, respectively; P ¼ 0.018), as well as an impaired objective vigilance test result (mean reaction time, 0.516, 0.497, and 0.579 ms, respectively; P < 0.001) occurred more frequently with R ESUM E enhanced negative intrathoracic pressure, 5 and thus increased cardiac workload. The long-term effects include the development of hypertension, 6 myocardial hypertrophy, atherosclerosis, and coronary artery disease, 7,8 contributing to the progression of heart failure and increased mortality rates. 9-11 Despite advances in medical and device therapy for CHF within the past 2 decades, SDB remains highly prevalent in patients with CHF. 12-15 Observational studies suggest that treatment of severe SDB with positive airway pressure (PAP) improves survival of patients with CHF. 10,11 In addition, PAP therapy improves quality of life and sleepiness, especially in those patients with CHF who present with SDB-related symptoms. 16-18
Respiratory Medicine, 2008
Background: Over 50% of patients with chronic heart failure (CHF) have sleep-disordered breathing (SDB). Any variation in the type of SDB in CHF will have implications for patient management. Currently there is good evidence for treatment of obstructive sleep apnea (OSA) in CHF with continuous positive airway pressure; however, for central sleep apnea (CSA) the treatment is less clear. Aims: The aim of this study was to investigate the variation in the severity and type of SDB (OSA vs. CSA) throughout 4 consecutive nights in CHF patients with SDB. Methods: Nineteen male CHF patients (mean7sd: age 6179 years; left ventricular ejection fraction: 34710% and percent predicted peak VO 2 : 67719%) underwent cardiorespiratory monitoring in their own home throughout 4 consecutive nights. Results: There was minimal variation in apnea-hypopnea index (AHI) throughout 4 nights in CHF patients with SDB [intraclass correlation coefficient (95% confidence interval ): 0.97 (95% CI 0.76 and 0.97)]. Eight patients [42% (95% CI 20% and 64%)] demonstrated a shift in the type of their SDB, from CSA to OSA or vice versa; these patients had significantly smaller neck circumference (group mean7sd) 4272 vs. 4472 cm; p ¼ 0.04), and had significant variation in the central AHI [intraclass correlation coefficient: 0.51 (95% CI 0.16 and 0.85)]. Conclusions: A single night of cardiorespiratory monitoring is representative of moderateto-severe SDB in patients with CHF. However, a high proportion of patients shift their type ARTICLE IN PRESS 0954-6111/$ -see front matter & (A. Vazir). Respiratory Medicine (2008) 102, 831-839
Circulation, 2003
Background-In patients with chronic heart failure (CHF), central sleep apnea (CSA) and enhanced ventilatory response (V E/V CO 2 slope) to exercise are common. Both breathing disorders alone indicate poor prognosis in CHF. Although augmented chemosensitivity to CO 2 is thought to be one important underlying mechanism for both breathing disorders, it is unclear whether both breathing disorders are related closely in patients with CHF. Methods and Results-We investigated 20 CHF patients with clinically important CSA (apnea-hypopnea-index (AHI), number of episodes per hour Ն15) and 10 CHF patients without CSA. Patients with and without CSA did not differ with respect to exercise capacity (peak V O 2 , 63.4Ϯ3.4% versus 60.8Ϯ4.4% of predicted value; Pϭ0.746) and left ventricular ejection fraction (LVEF, 31Ϯ2% versus 31Ϯ3%; Pϭ0.948). The AHI was not correlated with exercise capacity (peak V O 2 , percent of predicted value; Pϭ0.260) and LVEF (percent, Pϭ0.886). In contrast, the positive correlation of the V E/V CO 2 slope, determined by cardiopulmonary exercise testing, with the AHI was highly significant (PϽ0.001). The V E/V CO 2 slope was significantly increased in patients with CSA compared with those without CSA (29.7 versus 24.9; PϽ0.001). Conclusions-The ventilatory response to exercise is significantly augmented in CHF patients with CSA compared with those without. In contrast to peak V O 2 and LVEF, the V E/V CO 2 slope is strongly related to the severity of CSA in patients with CHF, which underscores an augmented chemosensitivity to CO 2 as a common underlying pathophysiological mechanism.