title: The first derivative as a means of synchronizing pulsatile flow velocity and vessel diameter waveforms in the fetal descending aorta.
abstract: In order to calculate volume flow, blood flow velocity and pulsatile vessel diameter waveforms in the lower thoracic part of the descending aorta of the fetal lamb and human fetus were matched for identical cardiac cycle length by fetal ECG and the first derivative of these waveforms. Volume flow values were not essentially different using either method. There is simultaneous onset of the blood flow velocity and pulsatile vessel diameter waveforms. The first derivative can reliably replace the fetal ECG as a means of synchronizing blood flow velocity and pulsatile vessel diameter waveforms in the fetal descending aorta.
authors.affiliation: Department of Obstetrics and Gynecology, Erasmus University, Rotterdam, The Netherlands.
authors.forename: H M
authors.initials: HM
authors.lastname: Tonge
authors.forename: P C
authors.initials: PC
authors.lastname: Struijk
authors.forename: C
authors.initials: C
authors.lastname: van Kooten
authors.forename: J W
authors.initials: JW
authors.lastname: Wladimiroff
authors.forename: N
authors.initials: N
authors.lastname: Bom
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000033:anatomy & histology / Q000502:physiology*; D001783:Blood Flow Velocity; D005333:Fetus / Q000502:physiology*; D006801:Humans; D011673:Pulsatile Flow; D012756:Sheep / Q000502:physiology*