title: Malignant neurocardiogenic vasovagal syncope associated with chronic exaggerated vagal tone.
abstract: A head-up tilt test was performed in a 23-year-old woman with a history of two syncopal episodes. The patient developed abrupt syncope with 48 seconds of sinus arrest. Analysis of the high frequency (HF) power of heart rate variability over 24 hours before and after metoprolol therapy showed a significantly elevated HF power in this patient compared to age- and sex-matched healthy subjects. It is suggested that an exaggerated resting vagal tone might be associated with the pathogenesis of prolonged asystole in our patient.
authors.affiliation: Department of Laboratory Medicine, Oita Medical University, 1-1 Idaigaoka, Hasama-machi, Oita 879-5593, Japan. mikinak@oita-med.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Nakagawa
authors.forename: N
authors.initials: N
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Yufu
authors.forename: T
authors.initials: T
authors.lastname: Fujino
authors.forename: T
authors.initials: T
authors.lastname: Ooie
authors.forename: H
authors.initials: H
authors.lastname: Yonemochi
authors.forename: S
authors.initials: S
authors.lastname: Nobe
authors.forename: M
authors.initials: M
authors.lastname: Hara
authors.forename: T
authors.initials: T
authors.lastname: Saikawa
authors.forename: M
authors.initials: M
authors.lastname: Ito
mesh_terms: D000328:Adult; D001146:Arrhythmia, Sinus / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008790:Metoprolol / Q000627:therapeutic use; D011187:Posture; D012016:Reference Values; D019462:Syncope, Vasovagal / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D018667:Tilt-Table Test; D016896:Treatment Outcome; D020421:Vagus Nerve Diseases / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy
chemical_list: D008790:Metoprolol