title: Effect of autonomic blockade on heart rate and blood pressure in sleep apnea syndrome.
abstract: To determine the impact of the autonomic nervous system on hemodynamic responses to sleep apnea we studied 7 male patients (48 +/- 6 years, BMI = 29.7 +/- 2.9 kg/m2) with an apnea index = 33 + 11/h. In two hypertensives, therapy was withdrawn 2 weeks before the study. During a full night polysomnography EEG, EOG, EMG, respiration, oximetry, heart rate (HR) and blood pressure (BP) (Finapres 23OOE) were recorded. Placebo and 3 short-acting autonomic blockers were randomly i.v. administered: antimuscarinic (atropine 1 mg, A), beta 1 blocker (esmolol 40 mg, E), alpha blocker (nicergoline 2.5 mg, N). A total of 367 obstructive apneas in NREM sleep were studied. With atropine, HR was increased at the beginning of apnea (P1)(74.5 +/- 2 bpm vs 65.4 +/- 2 bpm with placebo) and at the end apnea (P3) (76.6 +/- 1.9 bpm vs 67.1 +/- 1.76 bpm). At the resumption of breathing (RB), HR still increased (83.5 +/- 1.5 bpm vs 80.1 +/- bpm). Nicergoline had no significant effect on HR but significantly decreased SBP (117.8 +/- 1.4 mmHg vs 127 +/- 1.6 with placebo, p < 0.001). Nevertheless, the rise in BP from P3 to RB remained significant (p < 0.001). Esmolol significantly decreased HR at P1 (68.1 +/- 1.9 bpm vs 73.9 +/- 1.9 bpm) and at RB (75.9 +/- 1.9 vs 81.6 +/- 1.8). With A, the rise in HR at end-apnea (P3) suggests a vagal hyperactivity during this phase which is blunted at resumption when HR is unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D000328:Adult; D001285:Atropine; D001340:Autonomic Nerve Block; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008297:Male; D018727:Muscarinic Antagonists; D009530:Nicergoline; D010275:Parasympathetic Nervous System / Q000503:physiopathology; D011412:Propanolamines; D012143:Respiratory Physiological Phenomena; D012891:Sleep Apnea Syndromes / Q000188:drug therapy* / Q000503:physiopathology*
chemical_list: D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D018727:Muscarinic Antagonists; D011412:Propanolamines; D001285:Atropine; D009530:Nicergoline; C036604:esmolol