title: The effect of lower body weight support on arterial wave reflection in healthy adults.
abstract: Body weight support (WS) during treadmill exercise is used to rehabilitate orthopedic/neurological patients. WS lowers musculoskeletal strain and load. It compresses the lower body and increases intrathoracic volume. We studied short-term effects of WS on wave reflection indices using applanation tonometry during progressive WS of 25%, 50%, and 75% of body weight in 25 healthy men. WS decreased mean heart rate from 79 to 69 beats/min (P < .001). Peripheral and central mean arterial, systolic, and pulse pressures (PP) remained unchanged. There was a trend toward lower peripheral and central diastolic pressure. PP amplification ratio decreased significantly (P = .005). Reflected wave characteristics: Augmented pressure and index increased in a stepwise manner with WS (both P < .001). Both ejection duration and systolic duration of the reflected pressure wave (Ätr) increased progressively (both P < .001). The round-trip travel time (Δtp) was unchanged. Left ventricular workload and oxygen demand: Left ventricular wasted pressure energy increased (P < .001), and the subendocardial viability ratio decreased (P = .005), whereas the tension time index remained unchanged. In normal men, WS acutely decreases the PP amplification ratio, increases the amplitude and duration of the reflected aortic pressure wave, and increases measures of wasted left ventricular pressure energy and oxygen demand.
authors.affiliation: Division of Cardiovascular Medicine, State University of New York, Downstate Medical Center, Brooklyn, NY, USA.
authors.forename: Atif
authors.initials: A
authors.lastname: Afzal
authors.affiliation: Division of Cardiovascular Medicine, State University of New York, Downstate Medical Center, Brooklyn, NY, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Fung
authors.affiliation: Division of Cardiovascular Medicine, State University of New York, Downstate Medical Center, Brooklyn, NY, USA.
authors.forename: Sean
authors.initials: S
authors.lastname: Galligan
authors.affiliation: Human Performance Laboratory, State University of New York, Downstate Medical Center, Brooklyn, NY, USA.
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Godwin
authors.affiliation: Department of Surgery, State University of New York, Downstate Medical Center, Brooklyn, NY.
authors.forename: John G
authors.initials: JG
authors.lastname: Kral
authors.affiliation: Division of Cardiovascular Medicine, State University of New York, Downstate Medical Center, Brooklyn, NY, USA.
authors.forename: Louis
authors.initials: L
authors.lastname: Salciccioli
authors.affiliation: Division of Cardiovascular Medicine, State University of New York, Downstate Medical Center, Brooklyn, NY, USA. Electronic address: Jason.lazar@downstate.edu.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Lazar
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D005500:Follow-Up Studies; D064368:Healthy Volunteers; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D011187:Posture; D011311:Pressoreceptors / Q000502:physiology; D011446:Prospective Studies; D013599:Systole; D059289:Vascular Stiffness / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult
keywords: Aortic stiffness; applanation tonometry