Estimation of baroreflex sensitivity by the bivariate phase rectified signal averaging method: a comparison with the...

Area of Science:

• Cardiology
• Physiology
• Biomedical Engineering

Background:

• Spontaneous baroreflex sensitivity (BRS) is a crucial indicator of cardiovascular autonomic control.
• The phenylephrine test (Phe-BRS) is the established reference method for BRS assessment.
• A novel technique, bivariate phase-rectified signal averaging (PRSA-BRS), has emerged for BRS evaluation.

Purpose of the Study:

• To compare the novel PRSA-BRS method with the established Phe-BRS in heart failure (HF) and post-myocardial infarction (post-MI) patients.
• To assess the association and agreement between PRSA-BRS and Phe-BRS measurements.

Main Methods:

• The study included 192 HF patients and 41 post-MI patients.
• PRSA-BRS and Phe-BRS were measured and compared for association and agreement.
• Statistical analysis was performed to evaluate the relationship between the two methods.

Main Results:

• Both HF and post-MI patients showed statistically significant differences between Phe-BRS and PRSA-BRS values (p < 0.0001 and p = 0.001, respectively).
• Moderate association was observed between PRSA-BRS and Phe-BRS (r = 0.53, p < 0.0001 in HF; r = 0.43, p = 0.004 in post-MI).
• A large majority of PRSA-BRS measurements were lower than Phe-BRS, with significant disagreement and dependence on BRS magnitude.

Conclusions:

• While PRSA-BRS may contain relevant information on cardiac autonomic control, its significant disagreement with Phe-BRS precludes its use as a direct estimate of BRS.
• Discrepancies may stem from different measurement conditions, inclusion of non-baroreflex components, and computational normalization in PRSA-BRS.
• Further research is needed to understand the clinical utility and limitations of PRSA-BRS in evaluating baroreceptor-heart rate reflex function.