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.

The applicability of home blood pressure measurement in clinical practice: a review of literature.

PURPOSE: To review the literature on home blood pressure measurement (HBPM), to examine its validity and applicability for clinical practice and to provide recommendations regarding HBPM assessment. FINDINGS: HBPM can eliminate the white coat effect and offers the possibility to obtain multiple measurements under standardized conditions, which increases knowledge of overall blood pressure value. Although it is not entirely capable of replacing ambulatory blood pressure measurement (ABPM), HBPM correlates better with target organ damage and cardiovascular mortality than office blood pressure measurement (OBPM), it enables prediction of sustained hypertension in patients with borderline hypertension, and proves to be an appropriate tool for assessing drug efficacy. Additional advantages of HBPM are that it may increase drug compliance and patient's awareness of hypertension. Overall, OBPM yield higher blood pressure values than HBPM. Differences between OBPM and HBPM tend to increase with age and are generally higher in patients without antihypertensive treatment than in patients with antihypertensive treatment. RECOMMENDATIONS: Measurements should be performed according to accepted guidelines and recordings should be performed with a memory equipped automatic validated device. From the data reviewed here, we recommend that HBPM be assessed monthly by taking two measurements in the morning within 1 hour after awakening and two in the evening for three consecutive days, the data from the first day should be dismissed. A subject should be labeled hypertensive if his/her HBPM value is equal to or greater than 137 mmHg systolic and/or 84 mmHg diastolic.