Determination of baroreflex sensitivity during the modified Oxford maneuver by XXXX .

@entity1 @entity1854 @entity4375 @entity2357 @entity2647
BACKGROUND: Differences in spontaneous and drug-induced baroreflex sensitivity ( @entity4375 ) have been attributed to its different operating ranges. The current study attempted to compare @entity4375 estimates during cardiovascular steady-state and pharmacologically stimulation using an innovative algorithm for dynamic determination of baroreflex gain. METHODOLOGY/PRINCIPAL FINDINGS: Forty-five volunteers underwent the modified Oxford maneuver in supine and 60   tilted position with blood pressure and heart rate being continuously recorded. Drug-induced @entity4375 -estimates were calculated from data obtained by bolus injections of @entity1854 and @entity2647 . Spontaneous indices were derived from data obtained during rest (stationary) and under pharmacological stimulation (non-stationary) using the algorithm of @entity2357 ( @entity2357 ). Spontaneous and drug-induced @entity4375 values were significantly correlated and display directionally similar changes under different situations. Using the Bland-Altman method, systematic differences between spontaneous and drug-induced estimates were found and revealed that the discrepancy can be as large as the gain itself. Fixed bias was not evident with ordinary least products regression. The correlation and agreement between the estimates increased significantly when @entity4375 was calculated by @entity2357 in non-stationary mode during the drug injection period. @entity2357 - @entity4375 significantly increased during @entity2647 and decreased under @entity1854 . CONCLUSIONS/SIGNIFICANCE: The @entity2357 analysis provides a reliable, non-invasive assessment of @entity1 @entity4375 not only under static steady state conditions, but also during pharmacological perturbation of the cardiovascular system.
