Chest
Original ResearchSleep DisordersInverse Relationship of Subjective Daytime Sleepiness to Sympathetic Activity in Patients With Heart Failure and Obstructive Sleep Apnea
Section snippets
Subjects
Subjects were recruited from the HF clinics of the Mount Sinai Hospital and University Health Network/Toronto General Hospital without regard to whether they had any complaints of EDS or other symptoms of sleep apnea. Inclusion criteria were (1) HF with systolic dysfunction (left ventricle ejection fraction [LVEF] < 45% by two-dimensional echocardiography or radionuclide angiography); (2) stable condition and without medication adjustment for at least 1 month prior to participation; and (3) OSA
Results
Twenty-seven patients met the inclusion criteria. Their mean age was 50 ± 13 years; BMI, 31.7 ± 6.1 kg/m2; LVEF, 25.9% ± 7.9%; AHI, 39 ± 18 events/h of sleep; arousal index, 35 ± 18 events/h of sleep; mean Sao2, 94.2% ± 2.5%; minimal Sao2, 79% ± 10%; mean ESS score, 6.4 ± 3.3; and mean MSNA, 75 ± 17 bursts/100 cardiac cycles or 56 ± 11 bursts/min. Characteristics of the 13 less sleepy and 14 sleepier patients are shown in Table 1. There were no significant differences in age, BMI, sex
Discussion
The most important finding of our study was that in this group of 27 patients with HF and OSA, subjective daytime sleepiness assessed by the ESS score was inversely related to sympathetic activity quantified during wakefulness as MSNA burst incidence and burst frequency. Because multiunit MSNA is a reflection of nerve firing within a given cardiac cycle, the relationship between ESS and MSNA burst incidence was stronger because it excludes the confounding influence of heart rate. Differences in
Conclusions
In conclusion, our findings suggest that for a given severity of OSA in patients with HF, higher SNA counteracts the sleepiness-inducing effects of apnea-related hypoxia and sleep disruption. This raises the important question: What are the indications for treating OSA in patients with HF? EDS is the main indication for therapy of OSA in patients with and without HF because it has been shown in randomized trials that treating patients with OSA and an ESS score > 10 reduces sleepiness and
Acknowledgments
Author contributions: Dr Taranto Montemurro: contributed to the study design, data collection, data analysis and interpretation, and drafting and review of the manuscript for important intellectual content.
Dr Floras: contributed to the data analysis and interpretation, and drafting and review of the manuscript for important intellectual content.
Dr Millar: contributed to the data collection and review of the manuscript.
Dr Kasai: contributed to the data collection and review of the manuscript.
Mr
References (34)
Sympathetic nervous system activation in human heart failure: clinical implications of an updated model
J Am Coll Cardiol
(2009)- et al.
Obstructive sleep apnea and heart failure: pathophysiologic and therapeutic implications
J Am Coll Cardiol
(2011) - et al.
Inhibition of awake sympathetic nerve activity of heart failure patients with obstructive sleep apnea by nocturnal continuous positive airway pressure
J Am Coll Cardiol
(2005) - et al.
Insomnia as an interaction between sleep-interfering and sleep-interpreting processes
J Psychosom Res
(2000) - et al.
Hyperarousal and insomnia: state of the science
Sleep Med Rev
(2010) - et al.
Adenosine, energy metabolism and sleep homeostasis
Sleep Med Rev
(2011) - et al.
Influence of obstructive sleep apnea on mortality in patients with heart failure
J Am Coll Cardiol
(2007) - et al.
Sleepiness and sleep in patients with both systolic heart failure and obstructive sleep apnea
Arch Intern Med
(2006) - et al.
Sleep apnea in 81 ambulatory male patients with stable heart failure. Types and their prevalences, consequences, and presentations
Circulation
(1998) - et al.
Cardiovascular effects of continuous positive airway pressure in patients with heart failure and obstructive sleep apnea
N Engl J Med
(2003)
Sleep-disordered breathing in a general heart failure population: relationships to neurohumoral activation and subjective symptoms
J Sleep Res
Sympathetic activity in obese subjects with and without obstructive sleep apnea
Circulation
Sympathetic neural mechanisms in obstructive sleep apnea
J Clin Invest
Nonselective versus selective beta-adrenergic receptor blockade in congestive heart failure: differential effects on sympathetic activity
Circulation
Augmented sympathetic neural response to simulated obstructive apnoea in human heart failure
Clin Sci (Lond)
Immediate effects of arousal from sleep on cardiac autonomic outflow in the absence of breathing in dogs
J Appl Physiol
Muscle sympathetic nerve activity during wakefulness in heart failure patients with and without sleep apnea
Hypertension
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Funding/Support: This study was supported by the Canadian Institute of Health Research [operating grant MOP-82731], and by the Heart and Stroke Foundation of Canada, the Canada Foundation for Innovation, the Ontario Innovation Trust, and the Ministry of Research and Innovation.
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