title: The potent role of increased sympathetic tone in pathogenesis of essential hypertension with neurovascular compression.
abstract: OBJECTIVE
  To study the role of increased sympathetic tone in pathogenesis of hypertension in patients with essential hypertension with neurovascular compression.
  
  
  METHODS
  Twenty-three patients with essential hypertension, 13 patients with secondary hypertension, and 46 normotensive subjects were investigated. Neurovascular compression was evaluated by MRT. The power spectral components of heart rate variability as indices of autonomic nerve tone were determined to investigate the possibility that sympathetic tone mediates the neurovascular compression-induced increase in blood pressure.
  
  
  RESULTS
  Neurovascular compression of the rostral ventrolateral medulla (RVLM) was observed in 70% of essential hypertension group, none of secondary hyperension group and 16% of normotensive group (P < 0.001). The age-adjusted low-frequency power spectral density (A-PSD) (0.04 to 0.15 Hz), which is an index of sympathetic tone, was significantly higher in patients with essential hypertension (139.5 +/- 6.7%) with neurovascular compression than in essential hypertension patients without neurovascular compression (92.2 +/- 6.8%), normotensive subjects with (102.8 +/- 13.0%) and without neurovascular compression (100.1 +/- 4.1%), and patients with secondary hypertension (95.7 +/- 10.2%) (P < 0.001). There was no significant difference in the high-frequency A-PSD (0.15 to 0.40 Hz), which is an index of vagal tone, among groups.
  
  
  CONCLUSIONS
  Neurovascular compression was not always associated with an increase in sympathetic nerve tone. Hypertension was present in subjects with neurovascular compression, who had increased sympathetic tone but not in those with normal sympathetic tone. An increase in sympathetic tone may mediate the neurovascular compression-induced increase in blood pressure. Journal of Human Hypertension (2000) 14, 807-811
authors: Department of Cardiology, School of Medicine, Kanazawa Medical University, Japan. totoro@m-clinic.com
authors: T
authors: T
authors: Morise
authors: M
authors: M
authors: Horita
authors: I
authors: I
authors: Kitagawa
authors: R
authors: R
authors: Shinzato
authors: Y
authors: Y
authors: Hoshiba
authors: H
authors: H
authors: Masuya
authors: M
authors: M
authors: Suzuki
authors: N
authors: N
authors: Takekoshi
mesh_terms: D000328:Adult; D005260:Female; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000209:etiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008526:Medulla Oblongata / Q000502:physiology*; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000150:complications*; D012815:Signal Processing, Computer-Assisted; D013564:Sympathetic Nervous System / Q000502:physiology*