Hemodynamic Changes During Sleep in Hypertensive Patients

Hemodynamic studies were carried out during nonsedated all-night sleep on 14 patients with established hypertension. The significant changes from awake control values were as follows: mean arterial pressure fell 7.3% in stages I and II sleep and 8.8% in deep (stages III and IV) sleep; cardiac output decreased 10.3, 9.8, and 8.8% in stages I, II, and III and IV sleep, respectively; heart rate fell 4% in stage II sleep. Total peripheral resistance was not significantly altered. These hemodynamic responses during sleep were similar both quantitatively and qualitatively to those previously found in normal subjects. A small difference, which was of questionable significance, was noted between the two groups of subjects with respect to rapid eye movement sleep. While these observations do not disprove a primary neurogenic component in hypertension, they do not support such an hypothesis.