Iryna S Palamarchuk1, Jacquie Baker2, Kurt Kimpinski3. 1. Department of Clinical Neurological Sciences, University Hospital, London Health Sciences Centre, London, Ontario, Canada; Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada. 2. Department of Clinical Neurological Sciences, University Hospital, London Health Sciences Centre, London, Ontario, Canada. 3. Department of Clinical Neurological Sciences, University Hospital, London Health Sciences Centre, London, Ontario, Canada; Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada. Electronic address: kkimpin@uwo.ca.
Abstract
OBJECTIVE: To evaluate alpha and beta components of adrenergic baroreflex sensitivity (BRSa) in Valsalva maneuver (VM). METHODS: BRSa was studied in 89 healthy subjects aged 30±13 [16-75] years. Subjects were divided into three groups per blood pressure (BP) patterns associated with relatively balanced or increased alpha-adrenergic modulation: (1) BAR (n=43) - Balanced Autonomic Response with a BP dip below baseline in late phase II (IIL) and recovery in phase IV; (2) SAR (n=16) - Suppressed Autonomic Response with a non-dipping BP; and (3) AAR (n=30) - Augmented Autonomic Response with a BP recovery in phase IIL. Discrete (alpha and beta) BRSa formulae were produced using alpha- or beta-adrenergic phases: α-BRSa (phase IIL) and β-BRSa (phase IV), respectively. Discrete BRSa were studied to determine potential correlations to BRSa1 (validated BRSa evaluation) and evaluated for reliability. RESULTS: Patterns with higher α-adrenergic influence showed correlation between α-BRSa and BRSa1 (AAR: r=0.447, p<0.05; SAR: r=0.774, p<0.01). BAR showed correlation between β-BRSa and BRSa1 (r=-0.566, p<0.01), and α- and β-adrenergic coefficients (r=-0.381, p<0.05). Discrete BRSa were more reliable than BRSa1 (n=33; p<0.05). CONCLUSIONS: Discrete BRSa are reproducible and correlated with BRSa1. SIGNIFICANCE: If validated, discrete BRSa may differentiate physiologic variances and vague dysautonomia.
OBJECTIVE: To evaluate alpha and beta components of adrenergic baroreflex sensitivity (BRSa) in Valsalva maneuver (VM). METHODS: BRSa was studied in 89 healthy subjects aged 30±13 [16-75] years. Subjects were divided into three groups per blood pressure (BP) patterns associated with relatively balanced or increased alpha-adrenergic modulation: (1) BAR (n=43) - Balanced Autonomic Response with a BP dip below baseline in late phase II (IIL) and recovery in phase IV; (2) SAR (n=16) - Suppressed Autonomic Response with a non-dipping BP; and (3) AAR (n=30) - Augmented Autonomic Response with a BP recovery in phase IIL. Discrete (alpha and beta) BRSa formulae were produced using alpha- or beta-adrenergic phases: α-BRSa (phase IIL) and β-BRSa (phase IV), respectively. Discrete BRSa were studied to determine potential correlations to BRSa1 (validated BRSa evaluation) and evaluated for reliability. RESULTS: Patterns with higher α-adrenergic influence showed correlation between α-BRSa and BRSa1 (AAR: r=0.447, p<0.05; SAR: r=0.774, p<0.01). BAR showed correlation between β-BRSa and BRSa1 (r=-0.566, p<0.01), and α- and β-adrenergic coefficients (r=-0.381, p<0.05). Discrete BRSa were more reliable than BRSa1 (n=33; p<0.05). CONCLUSIONS: Discrete BRSa are reproducible and correlated with BRSa1. SIGNIFICANCE: If validated, discrete BRSa may differentiate physiologic variances and vague dysautonomia.
Authors: Bradley Porter; Martin J Bishop; Simon Claridge; Jonathan Behar; Benjamin J Sieniewicz; Jessica Webb; Justin Gould; Mark O'Neill; Christopher A Rinaldi; Reza Razavi; Jaswinder S Gill; Peter Taggart Journal: Front Physiol Date: 2017-05-29 Impact factor: 4.566