1,532 research outputs found
Assessing sodium sensitivity in clinical practice: new insights from ambulatory blood pressure monitoring data.
No full textSPECTRAL ANALYSIS OF BLOOD PRESSURE AND PULSE INTERVAL VARIABILITY FROM FINGER AND INTRA-ARTERIAL RECORDINGS
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The Wide Band Spectral Analysis: A New Insight Into Modulation of Blood Pressure, Heart Rate and Baroreflex Sensitivity
No full textSpontaneous Baroreflex Sensitivity: From the Cardiovascular Laboratory to Patient's Bedside
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Dynamic adaptation of cardiac baroreflex sensitivity to prolonged exposure to microgravity: data from a 16-day spaceflight
No full textDi Rienzo M, Castiglioni P, Iellamo F, Volterrani M, Pagani M, Mancia G, Karemaker JM, Parati G. Dynamic adaptation of cardiac baroreflex sensitivity to prolonged exposure to microgravity: data from a 16-day spaceflight. J Appl Physiol 105: 1569-1575, 2008. First published August 28, 2008; doi:10.1152/japplphysiol.90625.2008.-This study explored the process of arterial baroreflex adaptation to microgravity, starting from the first day of flight, during the 16-day STS-107 Columbia Space Shuttle mission. Continuous blood pressure (BP), ECG, and respiratory frequency were collected in four astronauts on ground (baseline) and during flight at days 0-1, 6-7, and 12-13, both at rest and during moderate exercise (75 W) on a cycle ergometer. Sensitivity of the baroreflex heart rate control (BRS) was assessed by sequence and spectral alpha methods. Baroreflex effectiveness index (BEI); low-frequency (LF) power and high-frequency (HF) power of systolic BP (SBP), diastolic BP (DBP), and R-R interval (RRI); the RRI LF/HF ratio; and the RRI root mean square of successive differences (RMSSD) index were also estimated. We found that, at rest, BRS increased in early flight phase, compared with baseline (means +/- SE: 18.3 +/- 3.4 vs. 10.4 +/- 1.2 ms/mmHg; P < 0.05), and it tended to return to baseline in subsequent days. During exercise, BRS was lower than at rest, without differences between preflight and in-flight values. At rest, in the early flight phase, RMSSD and RRI HF power increased (P < 0.05) compared with baseline, whereas LF powers of SBP and DBP decreased. No statistical difference was found in these parameters during exercise before vs. during flight. These findings demonstrate that heart rate baroreflex sensitivity and markers of cardiac vagal modulation are enhanced during early exposure to microgravity, likely because of the blood centralization, and return to baseline values in subsequent flight phases, possibly because of the fluid loss. No deconditioning seems to occur in the baroreflex control of the heart
Reply to Dr. Cysarz's comment on Point : Counterpoint "Cardiovascular variability is/is not an index of autonomic control of circulation"
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Role of arterial baroreflex in producing the 1/f shape of systolic blood pressure and heart rate spectra
No full textIn eight conscious cats, the spectral characteristics of systolic blood pressure and heart rate have been estimated before and after surgical opening of the arterial baroreflex obtained by denervation of carotid and aortic baroreceptors. Each spectrum was fitted by the 1/fα model and the residuals were analyzed to determine which regions of the spectra are reliably described by the model in intact conditions and after baroreflex denervation. The study indicated that the baroreflex plays a primary role in producing the 1/ fα shape of systolic pressure components at frequencies <0.02 Hz and of heart rate components in a band from 0.2 to 0.05 H
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