1. Obstructive Sleep Apnea and Cardiovascular Disease
James M. Parish, MD, Virend K. Somers, MD, PhD 
Mayo Clinic Proceedings 
Volume 79, Issue 8, Pages (August 2004)
DOI: /
Copyright © 2004 Mayo Foundation for Medical Education and Research Terms and Conditions

2. FIGURE 1
Recordings of sympathetic nerve activity, respiration, and intra-arterial blood pressure in an otherwise healthy patient with obstructive sleep apnea (OSA) during wakefulness (top left), during recurrent obstructive apneas (bottom panel), and during treatment with continuous positive airway pressure (CPAP) (top right). Even during wakefulness and normoxia, patients with OSA have high levels of resting sympathetic nerve activity. During obstructive apneas, chemoreflex activation by hypoxemia and hypercapnia causes even further increases in sympathetic activity, with recurrent surges in blood pressure most notable at the end of apneic events. Blood pressure increases up to 250/130 mm Hg even though the patient is normotensive during wakefulness. Treatment with CPAP lowers both sympathetic activation and blood pressure. REM = rapid eye movement. Reprinted from Somers et al,74 with permission from the American Society for Clinical Investigation.
Mayo Clinic Proceedings  , DOI: ( / )
Copyright © 2004 Mayo Foundation for Medical Education and Research Terms and Conditions