title: RR-SAP causality in heart transplant recipients.
abstract: An information domain approach to the assessment of causality was applied to the beat-to-beat variability of heart period and systolic arterial pressure to test the open loop condition along baroreflex in heart transplant recipients. The closed loop between heart period and systolic arterial pressure was detected as open at the level of the baroreflex if systolic arterial pressure is more easily predictable from heart period than vice versa according to a conditional entropy approach. We found that in short-term heart transplant (STHT) recipients (less than 2 years after transplantation) the closed loop between heart period and systolic arterial pressure was open at the level of baroreflex. Baroreflex appeared to be involved in the heart period regulation in long-term heart transplant (LTHT) recipients (more than 2 years after transplantation). The significant linear correlation of causality index on the number of months after transplantation suggests that baroreflex control recovers after transplantation.
authors.affiliation: Department of Technologies for Health, Galeazzi Orthopaedic Institute, University of Milan, Italy. alberto.porta@unimi.it
authors.forename: Alberto
authors.initials: A
authors.lastname: Porta
authors.forename: Valentina
authors.initials: V
authors.lastname: Magagnin
authors.forename: Tito
authors.initials: T
authors.lastname: Bassani
authors.forename: Eleonora
authors.initials: E
authors.lastname: Tobaldini
authors.forename: Nicola
authors.initials: N
authors.lastname: Montano
authors.forename: Philippe
authors.initials: P
authors.lastname: van de Borne
mesh_terms: D000368:Aged; D017704:Baroreflex; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods; D015984:Causality; D003198:Computer Simulation; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000601:surgery*; D006339:Heart Rate; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular