title: Ejection time: influence of hemodynamics and site of measurement in the arterial tree.
abstract: The left ventricular ejection time is routinely measured from a peripheral arterial waveform. However, the arterial waveform undergoes constant transformation as the pulse wave propagates along the arterial tree. Our goal was to determine if the left ventricular ejection time measured peripherally in the arterial tree accurately reflected the ejection time measured through the aortic valve. Moreover, we examined/accessed the modulating influence of hemodynamics on ejection time measurements. Continuous wave Doppler waveform images through the aortic valve and the simultaneously obtained radial artery pressure waveforms were analyzed to determine central and peripheral ejection times, respectively. The peripheral ejection time was significantly longer than the simultaneously measured central ejection time (174.5±25.2 ms vs. 120.7±14.4 ms; P<0.0001; 17.4±8.7% increase). Moreover, the ejection time prolongation was accentuated at lower blood pressures, lower heart rate and lower pulse wave velocity. The time difference between centrally and peripherally measured ejection times likely reflects intrinsic vascular characteristics. Moreover, given that the ejection time also depends on blood pressure, heart rate and pulse wave velocity, peripherally measured ejection times might need to be adjusted to account for changes in these variables.
authors.affiliation: Division of Cardiac Anesthesia, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Yurie
authors.initials: Y
authors.lastname: Obata
authors.affiliation: Department of Anesthesiology and Reanimatology, University of Fukui, Fukui, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Mizogami
authors.affiliation: Division of Cardiac Anesthesia, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Sarabdeep
authors.initials: S
authors.lastname: Singh
authors.affiliation: Division of Cardiac Anesthesia, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Nyhan
authors.affiliation: Division of Cardiac Anesthesia, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Dan E
authors.initials: DE
authors.lastname: Berkowitz
authors.affiliation: Division of Cardiac Anesthesia, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Jochen
authors.initials: J
authors.lastname: Steppan
authors.affiliation: Division of Cardiac Anesthesia, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Viachaslau
authors.initials: V
authors.lastname: Barodka
mesh_terms: D001021:Aortic Valve / Q000502:physiology*; D005260:Female; D006334:Heart Function Tests; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies