Adaptive-Lag approach for assessing baroreflex functions: validation with the eurobavar dataset

Area of Science:

• Physiology
• Autonomic Neuroscience
• Cardiovascular Regulation

Background:

• The arterial baroreflex is crucial for short-term blood pressure stabilization via autonomic control.
• Conventional Baroreflex Sensitivity (BRS) methods assume fixed delays, ignoring physiological reflex latency variability.
• This limitation affects the accuracy of assessing baroreflex function and diagnosing impairments.

Purpose of the Study:

• To develop and validate an Adaptive Lag (AL) Baroreflex Sensitivity (BRS) method that incorporates variable reflex delays.
• To compare the AL-BRS method against conventional sequence and spectral methods using the EuroBaVar dataset.
• To evaluate the diagnostic performance of AL-BRS and the novel Baroreflex Response Lag (BRL) for identifying baroreflex impairment.

Main Methods:

• Developed an Adaptive Lag (AL) BRS method allowing for variable delays (0-10 beats) between pressure and cardiac responses.
• Compared AL-BRS with conventional BRS methods (sequence, spectral) on 42 recordings from the EuroBaVar dataset.
• Calculated Baroreflex Response Lag (BRL) and assessed diagnostic performance using Area Under the Curve (AUC).

Main Results:

• The AL approach identified 34% more baroreflex sequences and showed excellent agreement (r=0.99) with fixed-lag BRS.
• Baroreflex Response Lag (BRL) was significantly longer in subjects with impaired baroreflex function (supine: 2.35 vs. 1.16 beats).
• AL-BRS (AUC=0.86) and BRL (AUC=0.87, standing AUC=0.95) demonstrated superior diagnostic performance for baroreflex impairment.

Conclusions:

• Incorporating variable response time into BRS assessment refines sensitivity estimation and reveals BRL as a diagnostically valuable temporal feature.
• The AL-BRS method offers a more physiologically complete assessment of baroreflex function.
• A refined, publicly available tool (MATLAB, R) is provided for research and clinical applications in autonomic regulation.