Improved time domain BRS assessment with the use of baroreflex events

The sequences technique is based on a linear regression of SBP and RR values in baroreflex sequences (BSs). In normal conditions most of BSs have 3 beats length and the estimated slope is potentially inaccurate. Also, the number of beats in BSs is approximately 25% of the total number of beats, evidencing that a large part of the data is discarded from BRS analysis. In this work, global BRS estimators combined with baroreflex events (BEs) are proposed as a way to improve BRS assessment in normal conditions and to allow its quantification in cases of BS absence. The results in the EuroBaVar dataset showed that the number of beats in BEs gets up to 50% of the total, with correlation between the corresponding SBP and RR values close to 0.8. Also, BRS assessment based on global estimators combined with BEs distinguishes Lying from Standing positions in all the subjects of that dataset, including those without identified BSs.