title: Effects of positive-pressure ventilation on the spontaneous baroreflex in healthy subjects.
abstract: To determine the short-term effects of noninvasive positive-pressure ventilation (PPV) on spontaneous baroreflex sensitivity, we acquired time series of R-R interval and beat-to-beat blood pressure in 55 healthy volunteers (mean age 46.5 +/- 10.5 yr) who performed breathing on four occasions at frequencies of 12 and 15 breaths/min without positive pressure (control) and also using PPV of 5 mbar. By using spectral and cross-spectral analysis, R-R interval variability and systolic blood pressure variability as well as the gain (alpha-index) of the baroreceptor reflex were estimated for the low-frequency and high-frequency (HF) bands. Compared with control breathing, PPV at 12 breaths/min and 15 breaths/min led to an increase in mean R-R (P < 0.001) and blood pressure (P < 0.05). The alpha-index of the HF band increased significantly for both respiratory frequencies (P < 0.05) due to PPV. These results indicate that short-term administration of PPV in normal subjects elicits a significant enhancement in the HF index of the baroreflex gain. These findings may contribute to understanding the mechanisms, indications, and effectiveness of positive pressure breathing strategies in treating cardiorespiratory and other disease conditions.
authors: Charité-Universitary Medicine Berlin, Department of Cardiology and Pulmology, Center of Sleep Medicine, Germany. ingo.fietze@charite.de
authors: Ingo
authors: I
authors: Fietze
authors: Dietrich
authors: D
authors: Romberg
authors: Martin
authors: M
authors: Glos
authors: Susanne
authors: S
authors: Endres
authors: Heinz
authors: H
authors: Theres
authors: Christian
authors: C
authors: Witt
authors: Virend K
authors: VK
authors: Somers
mesh_terms: D000328:Adult; D017704:Baroreflex / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration / Q000379:methods* / Q000706:statistics & numerical data; D015656:Respiratory Mechanics / Q000502:physiology*; D018709:Statistics, Nonparametric