title: Comparison of baroreflex sensitivity estimated from ECG R-R and inter-systolic intervals obtained by finger plethysmography and radial tonometry.
abstract: Spontaneous BRS estimates may considerable vary according to the technique of blood pressure and heart rate assessment. To optimise and standardise BRS estimation for clinical use we evaluated possible differences between spontaneous BRS indices estimated from either finger plethysmography or radial tonometry. Forty-five healthy volunteers underwent simultaneous recordings of electrocardiogram, finger plethysmography and radial tonometry in supine position and during 60° head-up tilt. BRS was computed by spectral analysis from either R-R time series and/or arterial pressure pulse. Radial tonometry generated higher mean BRS estimates than finger plethysmography. The difference decreased upon postural change from supine to upright. In the upright position, BRS estimates based on R-R interval proved to be generally lower compared to BRS indices estimated from arterial pressure pulse. The ratio of low-to-high-frequency power of inter-systolic interval and systolic blood pressure from tonometry was lower than that from plethysmography in supine and approximated in upright position. Spectral parameters of inter-systolic interval and R-R interval did not differ in supine but diverged in upright position. Changes of spectral parameters were most pronounced in R-R interval. Arterial pressure pulse is adequate for estimation of BRS under resting conditions but it may distort BRS estimates under physical load. We, therefore, recommend using an ECG signal for BRS estimation especially in non-stationary conditions.
authors.affiliation: Autonomic and Neuroendocrinological Laboratory, Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Viehweg
authors.affiliation: Autonomic and Neuroendocrinological Laboratory, Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany. manja.reimann@uniklinikum-dresden.de.
authors.forename: Manja
authors.initials: M
authors.lastname: Reimann
authors.affiliation: Autonomic and Neuroendocrinological Laboratory, Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Gasch
authors.affiliation: Autonomic and Neuroendocrinological Laboratory, Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany.
authors.forename: Heinz
authors.initials: H
authors.lastname: Rüdiger
authors.affiliation: Autonomic and Neuroendocrinological Laboratory, Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307, Dresden, Germany.
authors.forename: Tjalf
authors.initials: T
authors.lastname: Ziemssen
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D017704:Baroreflex / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D004562:Electrocardiography; D005260:Female; D005385:Fingers / Q000294:innervation* / Q000502:physiology; D064368:Healthy Volunteers; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D010991:Plethysmography; D011187:Posture; D013223:Statistics as Topic; D055815:Young Adult
keywords: Arterial pressure pulse; Baroreflex sensitivity; Finger plethysmography; Radial tonometry; Spectral analysis