title: Heart period and blood pressure characteristics in splanchnic arterial occlusion shock-induced collapse.
abstract: The nature of hemodynamic instability typical of circulatory shock is not well understood, but an improved interpretation of its dynamic features could help in the management of critically ill patients. The objective of this work was to introduce new metrics for the analysis of arterial blood pressure (ABP) in order to characterize the risk of catastrophic outcome in splanchnic arterial occlusion (SAO) shock. Continuous ABP (fs = 1 kHz) was measured in rats during experimental SAO shock, which induced a fatal pressure drop (FPD) in ABP. The FPD could either be slow (SFPD) or fast (FFPD), with the latter causing cardiovascular collapse. Time series of mean arterial pressure, systolic blood pressure and heart period were derived from ABP. The sample asymmetry-based algorithm Heart Rate Characteristics was adapted to compute the Heart Period Characteristics (HPC) and the Blood Pressure Characteristics (BPC). Baroreflex sensitivity (BRS) was assessed by means of a bivariate model. The approach to FPD of the animals who collapsed (FFPD) was characterized by higher BRS in the low frequency band versus SFPD animals (0.36 ± 0.15 vs. 0.19 ± 0.12 ms/mmHg, p value = 0.0196), bradycardia as indicated by the HPC (0.76 ± 0.57 vs. 1.94 ± 1.27, p value = 0.0179) and higher but unstable blood pressure as indicated by BPC (3.02 ± 2.87 vs. 1.47 ± 1.29, p value = 0.0773). The HPC and BPC indices demonstrated promise as potential clinical markers of hemodynamic instability and impending cardiovascular collapse, and this animal study suggests their test in data from intensive care patients.
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy. federico.aletti@polimi.it.|Department of Bioengineering, University of California San Diego, 9500 Gilman Drive MC 0412, La Jolla, CA, 92093-0412, USA. federico.aletti@polimi.it.
authors.forename: Federico
authors.initials: F
authors.lastname: Aletti
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy.
authors.forename: Nicolò
authors.initials: N
authors.lastname: Gambarotta
authors.affiliation: Department of Bioengineering, University of California San Diego, 9500 Gilman Drive MC 0412, La Jolla, CA, 92093-0412, USA.
authors.forename: Alexander H
authors.initials: AH
authors.lastname: Penn
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Ferrario
authors.affiliation: Department of Bioengineering, University of California San Diego, 9500 Gilman Drive MC 0412, La Jolla, CA, 92093-0412, USA.
authors.forename: Geert W
authors.initials: GW
authors.lastname: Schmid-Schönbein
mesh_terms: D000465:Algorithms; D000818:Animals; D017704:Baroreflex; D001794:Blood Pressure; D001795:Blood Pressure Determination; D002318:Cardiovascular Diseases / Q000503:physiopathology; D003422:Critical Care; D006321:Heart / Q000503:physiopathology; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D015233:Models, Statistical; D051381:Rats; D017208:Rats, Wistar; D012306:Risk; D012769:Shock / Q000503:physiopathology*; D013152:Splanchnic Circulation; D013997:Time Factors; D016896:Treatment Outcome
keywords: Baroreflex; Blood pressure characteristics; Cardiovascular variability; Heart period characteristics; Shock; Splanchnic arterial occlusion