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Comparative Study
. 2009 Jun;27(6):1243-51.
doi: 10.1097/HJH.0b013e32832a6e1b.

A comparison of pharmacologic and spontaneous baroreflex methods in aging and hypertension

Milos Milic  1 , Ping Sun, Fujun Liu, Claudia Fainman, Joel Dimsdale, Paul J Mills, Michael G Ziegler
Affiliations
Comparative Study

A comparison of pharmacologic and spontaneous baroreflex methods in aging and hypertension

Milos Milic et al. J Hypertens. 2009 Jun.

Abstract

Background: Phenylephrine bolus injection is an established technique to measure baroreflex sensitivity (BRS). This study quantified the relationship between the phenylephrine method and noninvasive measures of BRS and examined the effects of aging and hypertension on BRS. We also examined whether heart rate variability (HRV) provides as much information as does BRS.

Methods: BRS was determined by phenylephrine bolus (BRSphe), amyl nitrite inhalation (BRSamyl), Valsalva maneuver (BRSVals) and by time (BRS(+)) and spectral domain analysis (BRS(LFalpha), 004-015 Hz) of spontaneous blood pressure and R-R interval changes over the 5-min time period.

Results: The phenylephrine method significantly correlated with other methods (BRS(LFalpha) R = 0.54, BRS(+) R = 0.55, BRSVals R = 0.43 and BRSamyl R = 0.39; P < or = 0.001). Each method underestimated the BRSphe by the factors 0.62, 0.64, 0.59 and 0.33, respectively; P value less than 0.001. Only BRS(LFalpha) was significantly different between normotensive and hypertensive patients in young [24.3 +/- 1.4 (n = 40) vs. 12.2 +/- 2.3 (n = 7)] and middle-aged [16.5 +/- 1.1 (n = 71) vs. 10.8 +/- 1.1 (n = 31) groups, respectively]. HRV in the high frequency band (0.15-0.40 Hz) was significantly lower in young hypertensive patients than in normal controls (26 +/- 6.0 vs. 50 +/- 2.4, P < 0.05).

Conclusion: Although all methods correlated with the phenylephrine technique, none of them could be used interchangeably with that technique. BRS(LFalpha) detected the baroreflex loss of hypertension most clearly, and BRSamyl did not differ among groups.

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Figures

Fig. 1
Fig. 1
Comparison of differences between baroreflex methods and the phenylephrine method. (a—d) Relationship between the phenylephrine method and four other BRS measurement methods [spectral method (a), ramp method (b, c) and amyl nitrite method (d)]. All values are ln-transformed data. The dashed line is the line of identity, and the solid line is the best-fit regression between the two measures. (a1—d1) Bland—Altman plots of the difference between BRS measurements obtained with the one of four methods [spectral method (a1), ramp method (b1), Valsalva maneuver (c1), amyl nitrite method (d1)] versus the phenylephrine method. In these plots, there is proportionate bias if the slope of the regression is significantly different from zero. This is seen only in (a) revealing a proportionate bias between the phenylephrine method and BRSLFα. There is a fixed bias if the mean of the values differs from zero, and this is seen for four out of five measures. The dashed line shows the mean difference between the two methods, and the solid lines show the 95% limits of agreement between the two methods. gr1
Fig. 2
Fig. 2
Baroreflex sensitivity in relation to age and blood pressure status. (a) BRS determined by phenylephrine bolus method; (b) spontaneous BRS determined in spectral domain by low-frequency α coefficient (BRSLFα). BRS, baroreflex sensitivity; HTN, hypertension group. gr2
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References

    1. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology Heart rate variability: standards of measurement, physiological interpretation, and clinical use. Circulation. 1996;93:1043–1065. - PubMed
    1. La Rovere MT, Bersano C, Gnemmi M, Specchia G, Schwartz PJ. Exercise-induced increase in baroreflex sensitivity predicts improved prognosis after myocardial infarction. Circulation. 2002;106:945–949. - PubMed
    1. La Rovere MT, Bigger JTJ, Jr, Marcus FI, Mortara A, Schwartz PJ. Baroreflex sensitivity and heart-rate variability in prediction of total cardiac mortality after myocardial infarction. Lancet. 1998;351:478–484. - PubMed
    1. Smyth HS, Sleight P, Pickering GW. Reflex regulation of arterial pressure during sleep in man: a quantitative method of assessing baroreflex sensitivity. Circ Res. 1969;24:109–21. - PubMed
    1. Pagani M, Somers V, Furlan R, Dell’orto S, Conway J, Basselli G, et al. Changes in autonomic regulation induced by physical training in mild hypertension. Hypertension. 1988;12:600–610. - PubMed

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