title: Malignant vagotonia due to selective baroreflex failure.
abstract: Baroreflex failure is characterized by dramatic fluctuations of sympathetic activity and paroxysms of hypertension and tachycardia. In contrast, unopposed parasympathetic activity has not been described in patients with baroreflex failure because of concurrent parasympathetic denervation of the heart. We describe the unusual case of a patient with baroreflex failure in a setting of preserved parasympathetic control of HR manifesting episodes of severe bradycardia and asystole. Thus, parasympathetic control of the HR may be intact in occasional patients with baroreflex failure. Patients with this selective baroreflex failure require a unique therapeutic strategy for the control of disease manifestations.
authors.affiliation: Autonomic Dysfunction Center, Vanderbilt University, Nashville, Tenn 37232-2195, USA.
authors.forename: J
authors.initials: J
authors.lastname: Jordan
authors.forename: J R
authors.initials: JR
authors.lastname: Shannon
authors.forename: B K
authors.initials: BK
authors.lastname: Black
authors.forename: F
authors.initials: F
authors.lastname: Costa
authors.forename: A C
authors.initials: AC
authors.lastname: Ertl
authors.forename: R
authors.initials: R
authors.lastname: Furlan
authors.forename: I
authors.initials: I
authors.lastname: Biaggioni
authors.forename: D
authors.initials: D
authors.lastname: Robertson
mesh_terms: D017704:Baroreflex / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D001919:Bradycardia / Q000209:etiology / Q000503:physiopathology; D005260:Female; D018475:Head-Down Tilt / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007022:Hypotension / Q000209:etiology / Q000503:physiopathology; D008875:Middle Aged; D009422:Nervous System Diseases / Q000209:etiology / Q000503:physiopathology; D009638:Norepinephrine / Q000097:blood; D010275:Parasympathetic Nervous System / Q000503:physiopathology; D013268:Stimulation, Chemical; D016683:Supine Position / Q000502:physiology; D014630:Vagus Nerve / Q000503:physiopathology*; D014636:Valsalva Maneuver / Q000502:physiology
chemical_list: D009638:Norepinephrine