title: Effects of chronic baroreceptor stimulation on the autonomic cardiovascular regulation in patients with drug-resistant arterial hypertension.
abstract: In patients with drug-resistant hypertension, chronic electric stimulation of the carotid baroreflex is an investigational therapy for blood pressure reduction. We hypothesized that changes in cardiac autonomic regulation can be demonstrated in response to chronic baroreceptor stimulation, and we analyzed the correlation with blood pressure changes. Twenty-one patients with drug-resistant hypertension were prospectively included in a substudy of the Device Based Therapy in Hypertension Trial. Heart rate variability and heart rate turbulence were analyzed using 24-hour ECG. Recordings were obtained 1 month after device implantation with the stimulator off and after 3 months of chronic electric stimulation (stimulator on). Chronic baroreceptor stimulation decreased office blood pressure from 185+/-31/109+/-24 mm Hg to 154+/-23/95+/-16 mm Hg (P<0.0001/P=0.002). Mean heart rate decreased from 81+/-11 to 76+/-10 beats per minute(-1) (P=0.001). Heart rate variability frequency-domain parameters assessed using fast Fourier transformation (FFT; ratio of low frequency:high frequency: 2.78 versus 2.24 for off versus on; P<0.001) were significantly changed during stimulation of the carotid baroreceptor, and heart rate turbulence onset was significantly decreased (turbulence onset: -0.002 versus -0.015 for off versus on; P=0.004). In conclusion, chronic baroreceptor stimulation causes sustained changes in heart rate variability and heart rate turbulence that are consistent with inhibition of sympathetic activity and increase of parasympathetic activity in patients with drug-resistant systemic hypertension; these changes correlate with blood pressure reduction. Whether the autonomic modulation has favorable cardiovascular effects beyond blood pressure control should be investigated in further studies.
authors.affiliation: Departments of Cardiology and Cardiovascular Surgery, University Hospital Bern, Bern, Switzerland.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Wustmann
authors.forename: Jan P
authors.initials: JP
authors.lastname: Kucera
authors.forename: Ingrid
authors.initials: I
authors.lastname: Scheffers
authors.forename: Markus
authors.initials: M
authors.lastname: Mohaupt
authors.forename: Abraham A
authors.initials: AA
authors.lastname: Kroon
authors.forename: Peter W
authors.initials: PW
authors.lastname: de Leeuw
authors.forename: Jürg
authors.initials: J
authors.lastname: Schmidli
authors.forename: Yves
authors.initials: Y
authors.lastname: Allemann
authors.forename: Etienne
authors.initials: E
authors.lastname: Delacrétaz
mesh_terms: D000328:Adult; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001341:Autonomic Nervous System / Q000503:physiopathology*; D017704:Baroreflex / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002319:Cardiovascular System / Q000503:physiopathology*; D004351:Drug Resistance; D004599:Electric Stimulation Therapy / Q000295:instrumentation / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011311:Pressoreceptors / Q000502:physiology*; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D000959:Antihypertensive Agents