Investigating The Effect Of Systolic And Diastolic Arterial Pressures On Mean Pressure Through Partial Information Decomposition.

Mean arterial pressure (MAP) is a critical haemodynamic parameter, reflecting the average pressure during the cardiac cycle and serving as a determinant of tissue perfusion. Despite its clinical importance, MAP is often estimated using empirical formulas in routine practice, which may lead to inaccuracies. While previous studies have highlighted MAP's dynamic interactions with other physiological signals, the fast, within-beat relationships between MAP and blood pressure measurements - systolic arterial pressure (SAP) and diastolic arterial pressure (DAP) - remain underexplored. To fill this gap, this study leverages an information-theoretic framework based on partial information decomposition (PID) to dissect the unique, redundant, and synergistic contributions of SAP and DAP to MAP in healthy subjects during a protocol of postural stress. Two alternative definitions of redundancy were applied, yielding consistent findings. Specifically, an increase in redundancy during tilt and a dominant role of DAP in shaping MAP were documented across experimental conditions.