Non-invasive approach for the assessment of sympathetic baroreflex function: A feasibility study

Background: Evaluation of sympathetic baroreflex (sBR) function in humans requires intra-neural recording of muscle sympathetic nerve activity (MSNA) by microneurography. Aims: We proposed noninvasive approach for the evaluation of sBR function by applying the threshold-analysis (traditionally, based on MSNA) to systemic vascular resistance (SVR) measurement by photoplethysmography. Methods & results: In nine healthy subjects (5 M; age: 25 +/- 5y), the threshold-analysis was calculated twice: using MSNA and SVR. Both methods yield comparable results in men (T-50(hurst-vs.-svr): CV = 8.8%, r > 0.9; Slope(burst-svr): CV = 30.1%; r > 0.9), but not in women. Conclusions: SVR-based threshold-analysis is feasible in healthy young subjects and provides a promising alternative to the traditional MSNA-based approach. (C) 2017 Elsevier B.V. All rights reserved.