Sequence analysis of pulse transit time and systolic blood pressure during dynamic exercise

The pulse transit time (PTT), i.e. the time necessary to the arterial pulse to reach the periphery, and systolic arterial pressure (SAP) are inversely related (i.e. PTT decreases when increasing SAP). This relationship, although significant, is very weak at the level of PTT and SAP beat-to-beat variabilities. The study searches for sequences of PTT and SAP values characterized by a PTT increase (decrease) and SAP decrease (increase) in SAP and PTT variability series (i.e. SAP-/PTT+ and SAP+/PTT- sequences) derived from 13 healthy subjects during mild supine incremental bicycle exercise. The presence of these sequences on real data should guarantee that the SAP-PTT relationship might be sufficiently strong to encourage its exploitation in continuous non-invasive beat-to-beat SAP monitoring.