Sustained acute voltage-dependent blood pressure decrease with prolonged carotid baroreflex activation in therapy-resistant hypertension.
OBJECTIVE
Chronic carotid baroreflex stimulation (Rheos system) has been shown to effectively reduce blood pressure in patients with resistant hypertension. Upon acute stimulation blood pressure also falls as a function of voltage. the aim of this study is to evaluate whether this voltage-dependent blood pressure decrease is preserved after long-term carotid baroreflex stimulation.


METHODS
Forty-five patients implanted with Rheos underwent a voltage response test (VRT) before the start of carotid baroreflex activation (1m), as well as after 4 (4m) and 13 months (13 m) of device implantation. After switching off the device for 10 min (0 V), we started the VRT by increasing voltage from 1 to 6 V, by 1-V steps every 5 min. Blood pressure and heart rate were measured at the end of every step.


RESULTS
At 1m, mean blood pressure was 178/101 mmHg at 0 V and fell to 142/83 mmHg at 6 V. Heart rate fell from 75 to 65 beats/min. At 4m and 13 m mean blood pressure was significantly lower compared to 1m when VRT started at 0 V (170/96 and 161/93 mmHg, respectively). However, pattern of blood pressure decrease during VRT was comparable with this at 1m. Maximum SBP reduction during VRT did not change with long-term therapy.


CONCLUSIONS
Acute voltage-dependent blood pressure and heart rate decrease with electrical baroreflex stimulation is preserved after at least 1 year of continuous activation in patients with resistant hypertension. This indicates that response adaptation and nerve fatigue are very unlikely in long-term carotid baroreflex activation.
Department of Internal Medicine, Maastricht University Medical Center, Maastricht University, Maastricht, The Netherlands.
Teba
T
Alnima
Ingrid
I
Scheffers
Peter W
PW
De Leeuw
Bjorn
B
Winkens
Heidi
H
Jongen-Vancraybex
Jan H M
JH
Tordoir
Jürg
J
Schmidli
Markus G
MG
Mohaupt
Yves
Y
Allemann
Abraham A
AA
Kroon
D000959:Antihypertensive Agents / Q000627:therapeutic use; D017704:Baroreflex / Q000187:drug effects / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D002346:Carotid Sinus / Q000187:drug effects / Q000503:physiopathology*; D004351:Drug Resistance; D004599:Electric Stimulation Therapy / Q000379:methods*; D004567:Electrodes, Implanted; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011311:Pressoreceptors / Q000187:drug effects / Q000503:physiopathology*; D011446:Prospective Studies
D000959:Antihypertensive Agents