title: Effect of supine versus sitting position on noninvasive assessment of aortic pressure waveform: a randomized cross-over study.
abstract: Biomarkers derived noninvasively from the aortic blood pressure (BP) waveform provide information regarding cardiovascular (CV) risk independently of brachial BP (bBP). Although body position has significant impact on the assessment of bBP, its effect on aortic hemodynamics remains unknown. This study investigated the changes in both brachial and aortic hemodynamics, between the supine and sitting position. In this randomized cross-over study, the bBP and the aortic pressure waveform were assessed after a 5 min rest (sitting and supine in randomized order); aortic BP, pulse pressure (PP) amplification, augmentation index (AIx) and subendocardial viability index (SEVR) were assessed. Sixty-one subjects were examined (36 males, mean age 50±12 years). Mean BP did not differ between the sitting and supine position (110.8±13.7 vs 110.9±14.9, respectively, P=0.945). However, significant difference between the sitting and supine position in brachial PP (45.9±16.0 vs 52.6±15.6, respectively, P<0.001), aortic PP (36.7±15.2 vs 43.1±13.9, P<0.001), PP amplification (1.28±0.1 vs 1.23±0.1, P<0.001), AIx (26.9±11.9 vs 31.1±10.2, P<0.001) and SEVR (179.6±25.7 vs 161.2±25.8, P<0.001) were found. Review of the literature identified underestimation of the role of body position on aortic hemodynamics. In conclusion, increased PP in both the aorta and brachial artery were found in the supine compared to the sitting position. Reduced PP amplification and SEVR were further observed in the supine position, due to increased pressure wave reflections (AIx).
authors.affiliation: 1] Hypertension Center and Cardiovascular Research Laboratory, 1st Department of Propaedeutic Medicine, 'Laiko' Hospital Medical School, National and Kapodistrian University of Athens, Athens, Greece [2] Biomedical Engineering Unit, 1st Department of Cardiology, 'Hippokration' Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: D
authors.initials: D
authors.lastname: Vrachatis
authors.affiliation: Biomedical Engineering Unit, 1st Department of Cardiology, 'Hippokration' Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: T G
authors.initials: TG
authors.lastname: Papaioannou
authors.affiliation: Hypertension Center and Cardiovascular Research Laboratory, 1st Department of Propaedeutic Medicine, 'Laiko' Hospital Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Konstantopoulou
authors.affiliation: 1] Hypertension Center and Cardiovascular Research Laboratory, 1st Department of Propaedeutic Medicine, 'Laiko' Hospital Medical School, National and Kapodistrian University of Athens, Athens, Greece [2] Hypertension Center, 3rd University Department of Medicine, 'Sotiria' Hospital, Athens, Greece.
authors.forename: E G
authors.initials: EG
authors.lastname: Nasothimiou
authors.affiliation: Paris Descartes University; AP-HP; Diagnosis and Therapeutic Center, Hôtel-Dieu, Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Millasseau
authors.affiliation: Paris Descartes University; AP-HP; Diagnosis and Therapeutic Center, Hôtel-Dieu, Paris, France.
authors.forename: J
authors.initials: J
authors.lastname: Blacher
authors.affiliation: Paris Descartes University; AP-HP; Diagnosis and Therapeutic Center, Hôtel-Dieu, Paris, France.
authors.forename: M E
authors.initials: ME
authors.lastname: Safar
authors.affiliation: Hypertension Center and Cardiovascular Research Laboratory, 1st Department of Propaedeutic Medicine, 'Laiko' Hospital Medical School, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: P P
authors.initials: PP
authors.lastname: Sfikakis
authors.affiliation: Hypertension Center, 3rd University Department of Medicine, 'Sotiria' Hospital, Athens, Greece.
authors.forename: G S
authors.initials: GS
authors.lastname: Stergiou
authors.affiliation: 1] Hypertension Center and Cardiovascular Research Laboratory, 1st Department of Propaedeutic Medicine, 'Laiko' Hospital Medical School, National and Kapodistrian University of Athens, Athens, Greece [2] Hypertension Center, 3rd University Department of Medicine, 'Sotiria' Hospital, Athens, Greece.
authors.forename: A D
authors.initials: AD
authors.lastname: Protogerou
mesh_terms: D000328:Adult; D001011:Aorta / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D001916:Brachial Artery / Q000502:physiology; D018592:Cross-Over Studies; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D011187:Posture / Q000502:physiology*; D063177:Pulse Wave Analysis / Q000379:methods*; D019722:Sphygmomanometers; D016683:Supine Position / Q000502:physiology*