Positive Airway Pressure in Congestive Heart Failure

Sleep Medicine Clinics 09/2010; 5(3):393-405. DOI: 10.1016/j.jsmc.2010.05.011


Congestive heart failure (CHF) is a common disabling and costly condition, which is responsible for most hospital admissions and has a mortality rate on par with many malignancies. In recent years, positive airway pressure (PAP) has emerged as a novel therapeutic tool for pneumatically splinting open the sleep-related upper airway collapse; increasing lung volume, thereby increasing oxygen storage; and reducing the pressure gradient across the left ventricular wall, thereby reducing afterload. Strong evidence exists of physiologic efficacy and improved survival with PAP in acute pulmonary edema. Good evidence exists of physiologic improvement with PAP in chronic CHF associated with obstructive or central sleep apnea; however, good quality survival data are lacking.

Download full-text


Available from: Kirk Kee, Oct 10, 2015
55 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: There is some evidence to suggest that acetazolamide may improve obstructive sleep apnoea (OSA).However, how acetazolamide affects the key traits causing OSA remains uncertain. We aimed to investigate the effect of acetazolamide on the traits contributing to OSA and its severity. Acetazolamide (500 mg twice daily) was administered for 1 week to 13 OSA subjects. Pharyngeal anatomy/collapsibility, loop gain (LG), upper-airway muscle responsiveness (gain) and the arousal threshold were determined using multiple 3 min 'CPAP pressure drops': pharyngeal anatomy/collapsibility was quantified as the ventilation at CPAP=0. LG was defined as the ratio of the ventilatory overshoot to the preceding reduction in ventilation. Upper-airway gain was taken as the ratio of the increase in ventilation to the increase in ventilatory drive across the drop. Arousal threshold was quantified as the level of ventilatory drive associated with arousal. The apnoea-hypopnoea index (AHI)was assessed on separate nights using standard polysomnography. Acetazolamide reduced the median [interquartile range] LG (3.4 [2.4-5.4] versus 2.0 [1.4-3.5]; P <0.05) and NREM AHI (50 [36-57] versus 24 [13-42] events h-1; P <0.05), but did not significantly alter pharyngeal anatomy/collapsibility, upper-airway gain, or arousal threshold. There was a modest correlation between the percentage reduction in LG and the percentage reduction in AHI (r =0.660, P =0.05). Our findings suggest that acetazolamide can improve OSA, probably due to reductions in the sensitivity of the ventilatory control system. Identification of patients who may benefit from reductions in LG alone or in combination with other therapies to alter the remaining traits may facilitate pharmacological resolution of OSA in the future.
    The Journal of Physiology 01/2012; 590(Pt 5):1199-211. DOI:10.1113/jphysiol.2011.223925 · 5.04 Impact Factor