22350
document
Inhibition of awake sympathetic nerve activity of heart failure patients with obstructive sleep apnea by nocturnal continuous positive airway pressure . OBJECTIVES This study was designed to determine whether reductions in morning systolic blood pressure ( BP ) elicited by treatment of moderate to severe obstructive sleep apnea ( OSA ) in heart failure ( HF ) patients are associated with a reduction in sympathetic vasoconstrictor tone . BACKGROUND Daytime muscle sympathetic nerve activity ( MSNA ) is elevated in HF patients with coexisting OSA . In our recent randomized trial in HF , abolition of OSA by continuous positive airway pressure ( CPAP ) increased left ventricular ejection fraction ( LVEF ) and lowered morning systolic BP . METHODS Muscle sympathetic nerve activity , BP , and heart rate ( HR ) of medically treated HF patients ( EF < 45 % ) and OSA ( apnea-hypopnea index > or =20/h of sleep ) were recorded on the morning after overnight polysomnography , and again one month after patients were randomly allocated nocturnal CPAP treatment or no CPAP ( control ) . RESULTS In nine control patients , there were no significant changes in the severity of OSA , MSNA , systolic BP , or HR . In contrast , in the 8 CPAP-treated patients , OSA was attenuated , and there were significant reductions in daytime MSNA ( from 58 +/- 4 bursts/min to 48 +/- 5 bursts/min ; 84 +/- 4 bursts/100 heart beats to 72 +/- 5 bursts/100 heart beats ; p < 0.001 and p = 0.003 , respectively ) , systolic BP ( from 135 +/- 5 mm Hg to 120 +/- 6 mm Hg , p = 0.03 ) , and HR ( from 69 +/- 2 min ( -1 ) to 66 +/- 2 min ( -1 ) ; p = 0.013 ) . CONCLUSIONS Treatment of coexisting OSA by CPAP in HF patients lowers daytime MSNA , systolic BP , and HR . Inhibition of increased central sympathetic vasoconstrictor outflow is one mechanism by which nocturnal CPAP reduces awake BP in HF patients with moderate to severe OSA .
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Intervention_Physical
nocturnal continuous positive airway pressure
22352
Intervention_Physical
continuous positive airway pressure ( CPAP )
22353
Intervention_Physical
nocturnal CPAP treatment
22354
Intervention_Control
no CPAP ( control )
22355
Intervention_Physical
CPAP-treated
22356
Intervention_Physical
CPAP
22357
Intervention_Physical
nocturnal CPAP
22358
Outcome_Physical
morning systolic blood pressure ( BP )
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Outcome_Physical
obstructive sleep apnea
22360
Outcome_Physical
sympathetic vasoconstrictor tone
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Outcome_Physical
Daytime muscle sympathetic nerve activity ( MSNA )
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Outcome_Physical
left ventricular ejection fraction ( LVEF )
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Outcome_Physical
morning systolic BP
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Outcome_Physical
Muscle sympathetic nerve activity
22365
Outcome_Physical
BP
22366
Outcome_Physical
heart rate ( HR )
22367
Outcome_Physical
apnea-hypopnea index
22368
Outcome_Physical
OSA
22369
Outcome_Physical
MSNA
22370
Outcome_Physical
systolic BP ,
22371
Outcome_Physical
HR
22372
Outcome_Physical
OSA
22373
Outcome_Physical
daytime MSNA
22374
Outcome_Physical
systolic BP
22375
Outcome_Physical
HR
22376
Outcome_Physical
daytime MSNA
22377
Outcome_Physical
systolic BP
22378
Outcome_Physical
HR .
22379
Outcome_Physical
BP
22380
Participant_Condition
heart failure
22381
Participant_Condition
obstructive sleep apnea
22382
Participant_Condition
heart failure ( HF )
22383
Participant_Condition
HF
22384
Participant_Condition
coexisting OSA
22385
Participant_Condition
HF
22386
Participant_Condition
OSA
22387
Participant_Sample-size
nine
22388
Participant_Sample-size
8
22389
Participant_Condition
coexisting OSA
22390
Participant_Condition
HF
22391
Participant_Condition
HF
22392
Participant_Condition
OSA