A new approach for noninvasive baroreflex sensitivity assessment: preliminary results

Presents a new method for noninvasive assessment of baroreceptor sensitivity (BRS). Using this new method, BRS is estimated by linear regression analysis of the instantaneous values of BRS reordered into a logical, ascending sequence. The performance of the new method was compared with measurements of BRS by the traditional bolus phenylephrine method and other well-known non-invasive BRS assessment techniques, such as the "spontaneous sequences" and the "correlated modulus" methods, in 19 subjects. The BRS of the entire population was 8.31±3.90 ms/mmHg for the phenylephrine method, 8.39±4.21 ms/mmHg for the new method, and 12.6±6.72 ms/mmHg for the spontaneous sequences method. However, estimation of BRS using the modulus method was only valid for five subjects (weighted coherence >0.5) with a BRS of 10.41±4.18 ms/mmHg. The estimates of BRS derived from the four methods were significantly correlated for these five subjects. This result suggests that, with further refinements, the new method may be used for reliable non-invasive estimation of BRS