This Article Full Text Full Text (PDF) All Versions of this Article: 50/1/41    most recent HYPERTENSIONAHA.107.090308v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Hesse, C. Articles by Eisenach, J. H. Search for Related Content PubMed PubMed Citation Articles by Hesse, C. Articles by Eisenach, J. H. Related Collections Autonomic, reflex, and neurohumoral control of circulation

(Hypertension. 2007;50:41.)
© 2007 American Heart Association, Inc.

Original Articles

Baroreflex Sensitivity Inversely Correlates With Ambulatory Blood Pressure in Healthy Normotensive Humans

Christiane Hesse; Nisha Charkoudian; Zhong Liu; Michael J. Joyner; John H. Eisenach

From the Departments of Anesthesiology (C.H., Z.L., M.J.J., J.H.E.) and Physiology and Biomedical Engineering (N.C.), Mayo Clinic, Rochester, Minn; and the Department of Cardiology (Z.L.), First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.

Correspondence to John H. Eisenach, Department of Anesthesiology, Mayo Clinic and Foundation, 200 First St SW, Rochester, MN 55905. E-mail Eisenach.John{at}mayo.edu

Patients with hypertension have a blunted sensitivity of baroreflex control of heart period. In these patients, baroreflex sensitivity is positively related to heart rate variability and inversely related to blood pressure variability. We hypothesized that this relationship would also be evident in healthy normotensive subjects and that individuals with higher baroreflex sensitivity would have lower ambulatory 24-hour blood pressure. Twenty-four-hour ambulatory blood pressure and heart rate were recorded in 50 healthy, normotensive, nonobese individuals (31 women and 19 men). The baroreflex was assessed using sequential bolus administration of sodium nitroprusside and phenylephrine, and baroreflex sensitivity was calculated as the slope of the relation between systolic blood pressure and R-R interval during the resulting blood pressure transients. Baroreflex sensitivity was inversely correlated to 24-hour average mean arterial pressure (R=0.49; P<0.001) and positively related to daytime heart rate variability (R=0.33; P=0.02). In contrast, no relationship was found between baroreflex sensitivity and 24-hour heart rate or blood pressure variabilities. We conclude that the relationship between baroreflex sensitivity and daytime heart rate variability was similar to that reported previously in hypertensive subjects. Furthermore, the inverse relation between baroreflex sensitivity and mean arterial pressure supports the idea that the baroreflex may exert longer-term effects on blood pressure than thought previously.

Key Words: baroreflex • ambulatory blood pressure monitoring • heart rate variability • blood pressure variability • normotension