Baroreflex sensitivity

Decrease baroreflex sensitivity Decrease -receptor response Decrease 2 -receptor response Increase sensitivity to barbiturates Decrease glucose tolerance... 

A polymorphism in the endothelin -receptor gene is linked to baroreflex sensitivity. J Hypertens 23 2019-2026... 

Baroreflex sensitivity (BRS) is a measure of the reflex bradycardia that follows an increase in systemic blood pressure. This reflex is mediated by arterial baroreceptors and may be measured after injection of phenylephrine or after spontaneous rises in blood pressure (64). Correlation between the two different tests is poor (69) and measures of baroreflex sensitivity are only moderately reproducible (70). Data on the ability of BRS to predict sudden death are conflicting. In the ATRAMI study in 1284 patients post-MI, HRV, and BRS were assessed at discharge (71). Depressed HRV and BRS carried a significant risk of cardiac mortality when both parameters were depressed the risk increased further. Thus, ATRAMI demonstrated that since BRS adds to the prognostic value of HRV, the two measures are complimentary rather than redundant. However, in another study of 700 post-MI patients, HRV or BRS was not predictive of SCD (60). BRS also does not appear useful for risk stratification in patients with nonischemic cardiomyopathy (63). 

Stein, KM. Noninvasive Risk Stratification for Sudden Death Signal-Averaged Electrocardiography, Nosustained Ventricular Tachycardia, Heart Rate Variability, Baroreflex Sensitivity, and QRS Duration. Prog Cardiovasc Dis 2008 51(2) 106—17. 

Maestri R, Pinna GD, Mortara A, La Rovere MT, Tavazzi L. Assessing baroreflex sensitivity in post-myocardial infarction patients comparison of spectral and phenylephrine techniques. JAm Coll Cardiol 1998 31(2) 344-351. 

La Rovere MT, Bigger JT Jr, Marcus FI, Mortara A, Schwartz PJ. Baroreflex sensitivity and heart-rate variability in prediction of total cardiac mortality after myocardial infarction. ATRAMI (Autonomic tone and reflexes after myocardial infarction) investigators. Lancet 1998 351(9101) 478-84. 

La Rovere MT, Pinna GD, Hohnloser SH. Baroreflex sensitivity and heart rate variability in the identification of patients at risk for life-threatening arrhythmias implications for clinical trials. Circulation 2001 103(16) 2072-7. 

Watanabe Y, lida H, Tanabe K, Ohata H, Ddii S. Clonidine premedicaticxi modifies rei nses to adrenoceptOT agonists and baroreflex sensitivity. CanJAnaesth (1998) 45,1084-1090. 

The responses to mental workload in this model depend, except firr the reduction of baroreflex-sensitivity, on the interference of respiration and blood pressure control on feedback gains, sympathic and vagal tone, and so on. "More than hundred combinations of their values were tested and the results showed various patterns of changes in HR, MBP and their RF and MF s [mid frequency component of HRV] that explained the divergence of experimental observations" (Ohsuga et ab, 1995, p. 774). 

Blood pressure increases in the first part of the session and decreases thereafter. Interbeat interval time (IBI) increases in the first part of the session, while it decreases in the last part of the session baroreflex sensitivity (BRS) follows the IBI pattern exactly. HRV, however, follows a different time course. A simple conclusion fiom the experimental data has to be that the cardiovascular data during long-term task performance is quite different from a pattern that mostly occurs during short-lasting laboratory tasks. The simulation results show... 

Other noninvasive techniques to identify risk, such as baroreflex sensitivity, spectral turbulence (45 7), heart rate variability, T-wave altemans (48-51), QT interval prolongation, QT dispersion (52,53), and late potentials (by the signal averaged ECG) (54-56), have been considered in select patient populations (Table 14.2). AU have failed to live up to initial promises. 

Dorantes Mendez G, Aletti F, Toschi N, CanicheUa A, Dauri M, Conigiione F, et al. Baroreflex sensitivity variations in response to propofol anesthesia comparison between normotensive and hypertensive patients. J Clin Monit Comput 2013 27 417-26. 

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