Sustained acute voltage-dependent blood pressure decrease with prolonged carotid baroreflex activation in therapy-resistant hypertension
Journal of Hypertension, 07/31/2012
Alnima T et al. – 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.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 (13m) of device implantation.
- After switching off the device for 10min (0V), authors started the VRT by increasing voltage from 1 to 6V, by 1–V steps every 5min.
- Blood pressure and heart rate were measured at the end of every step.
- At 1m, mean blood pressure was 178/101mmHg at 0V and fell to 142/83mmHg at 6V.
- Heart rate fell from 75 to 65 beats/min.
- At 4m and 13m mean blood pressure was significantly lower compared to 1m when VRT started at 0V (170/96 and 161/93mmHg, 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.