A new approach for noninvasive baroreflex sensitivity assessment: Preliminary results

This paper 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 reorder in 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 noninvasive 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 5 subjects (weighted coherence >0.5) with BRS of 10.41 ± 4.18 ms/mmHg. The estimates of BRS derived from the four methods were significantly correlated for these 5 subjects. This result suggests that with further refinements, the new method may be used for reliable noninvasive estimation of BRS.