title: Reduced parasympathetic cardiac control in patients with hypertension at rest and under mental stress.
abstract: The neurogenic component in the pathogenesis of essential hypertension has predominantly been analyzed with regard to the sympathetic part of the autonomous nervous system; the parasympathetic branch has largely been neglected. We investigated whether 54 normotensive (mean causal blood pressure [cBP]: 125 +/- 6/82 +/- 4 mm Hg), 41 borderline hypertensive (cBP: 134 +/- 8/90 +/- 5 mm Hg), and 34 hypertensive men (cBP: 152 +/- 13/101 +/- 5 mm Hg) without secondary target organ damage differed in parasympathetic cardiac control. Parasympathetic cardiac control was assessed via the amount of fast fluctuations (0.15 to 0.40 Hz; vagus band) and by the amount of respiratory-linked fluctuations (mean respiratory frequency +/- 0.03 Hz) in the power spectra of continuously registered interbeat intervals under the following conditions: mean of three rest phases with 10, 5, and 5 minutes' duration (REST); mean of two modes of a reaction time task with 10 and 5 minutes' duration (RTT); mean of 5 minutes' mental arithmetic plus noise (MA). Analysis of variance (ANOVA) shows that spectral energy in the so-called vagus band reveals the most prominent differences between blood pressure groups under all conditions: REST = normotensive, 2.70 +/- 0.31; borderline hypertensive, 2.55 +/- 0.33; and hypertensive, 2.43 +/- 0.43 (F[2.126] = 6.19; p < 0.01). RTT = normotensive, 2.41 +/- 0.35; borderline hypertensive, 2.19 +/- 0.33; and hypertensive, 2.17 +/- 0.46 (F[2.126] = 6.04; p < 0.01); MA = normotensive, 2.69 +/- 0.34; borderline hypertensive, 2.52 +/- 0.33; and hypertensive, 2.38 +/- 0.46 (F[2.126] = 7.04; p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Psychosomatic Medicine, University Hospital Basel, Switzerland.
authors.forename: W
authors.initials: W
authors.lastname: Langewitz
authors.forename: H
authors.initials: H
authors.lastname: Rüddel
authors.forename: H
authors.initials: H
authors.lastname: Schächinger
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001794:Blood Pressure / Q000502:physiology; D016022:Case-Control Studies; D005583:Fourier Analysis; D006321:Heart / Q000294:innervation*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted; D013312:Stress, Physiological / Q000503:physiopathology; D013564:Sympathetic Nervous System / Q000502:physiology / Q000503:physiopathology; D014630:Vagus Nerve / Q000502:physiology / Q000503:physiopathology*