title: Causal cross-spectral analysis of heart rate and blood pressure variability for describing the impairment of the cardiovascular control in neurally mediated syncope.
abstract: A causal approach to the calculation of coherence and transfer function between systolic pressure (SP) and RR interval variability was applied in eight patients and eight control subjects during prolonged tilt test for investigating the impairment of cardiovascular control related to neurally mediated syncope. The causal analysis showed a depressed baroreflex regulation in resting patients, with reduced gain and increased latency from SP to RR, and a drop of the baroreflex coupling immediately before syncope. These findings, which were not elicited by traditional cross-spectral analysis, strongly suggest the use of the causal approach for the study of syncope mechanisms.
authors.affiliation: Laboratorio Biosegnali, Dipartimento di Fisica, Università di Trento, Italy. faes@science.unitn.it
authors.forename: Luca
authors.initials: L
authors.lastname: Faes
authors.forename: Lamberto
authors.initials: L
authors.lastname: Widesott
authors.forename: Maurizio
authors.initials: M
authors.lastname: Del Greco
authors.forename: Renzo
authors.initials: R
authors.lastname: Antolini
authors.forename: Giandomenico
authors.initials: G
authors.lastname: Nollo
mesh_terms: D000328:Adult; D000465:Algorithms; D017704:Baroreflex; D001794:Blood Pressure; D002319:Cardiovascular System / Q000503:physiopathology; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005246:Feedback; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D015233:Models, Statistical; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013223:Statistics as Topic; D019462:Syncope, Vasovagal / Q000175:diagnosis* / Q000503:physiopathology*