• A Porta, C Gasperi, G Nollo, D Lucini, P Pizzinelli, R Antolini, and M Pagani.
• Dipartimento di Scienze Precliniche, LITA di Vialba, Laboratorio di Modellistica di Sistemi Complessi, Universita degli Studi di Milano, Via G.B. Grassi 74, 20157, Milano, Italy. alberto.porta@unimi.it
• Med Biol Eng Comput. 2006 Apr 1; 44 (4): 331-7.

AbstractGlobal linear analysis has been traditionally performed to verify the relationship between pulse transit time (PTT) and systolic arterial pressure (SAP) at the level of their spontaneous beat-to-beat variabilities: PTT and SAP have been plotted in the plane (PTT,SAP) and a significant linear correlation has been found. However, this relationship is weak and in specific individuals cannot be found. This result prevents the utilization of the SAP-PTT relationship to derive arterial pressure changes from PTT measures on an individual basis. We propose a local linear approach to study the SAP-PTT relationship. This approach is based on the definition of short SAP-PTT sequences characterized by SAP increase (decrease) and PTT decrease (increase) and on their search in the SAP and PTT beat-to-beat series. This local approach was applied to PTT and SAP series derived from 13 healthy humans during incremental supine dynamic exercise (at 10, 20 and 30% of the nominal individual maximum effort) and compared to the global approach. While global approach failed in some subjects, local analysis allowed the extraction of the gain of the SAP-PTT relationship in all subjects both at rest and during exercise. When both local and global analyses were successful, the local SAP-PTT gain is more negative than the global one as a likely result of noise reduction.

12 keywords...

hide…