title: Orthostatic response of cephalic blood flow using a mini laser Doppler blood flowmeter and hemodynamics of a new active standing test.
abstract: OBJECTIVE
  Cephalic hemodynamic assessment is important in initial orthostatic hypotension. We sought to investigate cephalic blood flow (CBF) in the earlobe using a mini laser Doppler flowmeter (LDF) during orthostatic challenge. In addition, we clarified hemodynamic differences during a new active standing protocol using a footstool standing test (FST) with bending of the legs on the footstool in the sitting position to reduce the load of the squatting posture in the conventional squat standing test (SST).
  
  
  METHODS
  Ten healthy men (21 ± 0.5 years) performed the SST after a 1 min squat and the FST after a 1 min load consisting of bending the legs on a footstool in the sitting position. Earlobe CBF, beat-to-beat arterial blood pressure (ABP), mean arterial blood pressure (MAP), and heart rate (HR) were recorded during each test.
  
  
  RESULTS
  Earlobe CBF showed a transient fall synchronized with the ABP during each test. No significant differences in the recovery times (RTs) of CBF and MAP were observed during the SST (CBF 12.9 ± 0.6 s vs. MAP 12.1 ± 0.5 s, P = 0.313) and FST (CBF 10.6 ± 0.4 s vs. MAP 10.1 ± 0.8 s, P = 0.552). Although the CBF and ABP decreases were not different in each test, the HR increase was significantly lower with the FST (24 ± 2 bpm) than with the SST (31 ± 3 bpm, P < 0.005).
  
  
  CONCLUSIONS
  Earlobe CBF reflects the compensatory ABP regulatory response during standing and is potentially useful for estimating the orthostatic ABP response indirectly. Furthermore, the FST is a low-load protocol that can be an effective protocol for a standing test of cardiac function.
authors.affiliation: Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Cyuo-shi, Yamanashi, 409-3898, Japan. masaki_goma@post.pioneer.co.jp.|Research and Development Division, Pioneer Corporation, 1-1 Shin-Ogura, Saiwai-ku, Kawasaki-shi, Kanagawa, 212-0031, Japan. masaki_goma@post.pioneer.co.jp.
authors.forename: Masaki
authors.initials: M
authors.lastname: Goma
authors.affiliation: Research and Development Division, Pioneer Corporation, 1-1 Shin-Ogura, Saiwai-ku, Kawasaki-shi, Kanagawa, 212-0031, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kimura
authors.affiliation: Department of Laboratory Medicine, School of Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima-shi, Fukushima, 960-1295, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shimura
authors.affiliation: Third Department of Internal Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Cyuo-shi, Yamanashi, 409-3898, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kaneshige
authors.affiliation: Third Department of Internal Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Cyuo-shi, Yamanashi, 409-3898, Japan.|Okinaka Memorial Institute for Medical Research, 2-2-2 Toranomon, Minato-ku, Tokyo, 105-8470, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Department of Biomedical Engineering, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama, 350-8585, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kikuchi
authors.affiliation: Department of Biomedical Engineering, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama, 350-8585, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Terada
mesh_terms: D001794:Blood Pressure; D004431:Ear, External / Q000098:blood supply*; D006439:Hemodynamics; D006801:Humans; D007024:Hypotension, Orthostatic / Q000503:physiopathology*; D017078:Laser-Doppler Flowmetry; D008297:Male; D012039:Regional Blood Flow; D055815:Young Adult
keywords: Arterial blood pressure; Cephalic blood flow; Initial orthostatic hypotension; Laser Doppler flowmeter; Orthostatic challenge