Effect Baroreflex Activation Therapy on the Carotid Body

Maastricht University Medical Center20 enrolled

Overview

Carotid baroreflex activation therapy (BAT) by the Rheos® system produces a sustained fall in blood pressure in patients with resistant hypertension. Since the activation electrodes are implanted at the level of the carotid sinus, it is conceivable that the nearby located carotid body chemoreceptors are stimulated as well. Physiological stimulation of carotid chemoreceptors not only raises respiration, but it also increases sympathetic activity which may in part counteract the effects of BAT. The aim of the present study is to investigate whether there is evidence for concomitant carotid chemoreflex activation during BAT. We hypothesized that there is no clinically relevant co-activation of the carotid body chemoreceptors during BAT in patients with resistant hypertension.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Hypertension Resistant To Conventional Therapy Baroreflex Carotid Body

Eligibility

Sex: ALLMin age: 21 YearsMax age: 75 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Be currently implanted with Rheos system and have completed the 13-month follow-up period. * Be on stable anti-hypertensive therapy for at least 4 weeks prior to inclusion, where stable is defined as no changes in medications or dosage of medications. * Have at least one functional carotid baroreflex activation electrode. * Have signed and approved informed consent form for participation in this study. Exclusion Criteria: * Myocardial infarction (MI) or cerebral vascular accident (CVA) within the past 90 days, or subject is still unstable from a prior MI or CVA that occurred more than 90 days ago. * Are unable or unwilling to comply with the protocol requirements of this study. * Diagnosed with severe chronic obstructive lung disease (COPD/asthma GOLD stadium III and IV).

Outcomes

Primary Outcomes

Change in arterial CO2 (PaCO2) during baroreflex activation therapy

During one hour several device activation settings will be programmed at random. During each device setting we will collect arterial blood samples to check for PaCO2.

Time frame: 6 times during different electrical activation settings within one hour

Secondary Outcomes

Change in end-tidal CO2 during baroreflex activation therapy

Change in respiratory variables will be analyzed during the aforementioned time frame in which we will program several device activation settings.

Time frame: 1 - 1.25 hour

Change in blood pressure during baroreflex activation therapy

The change in cardiovascular variables will be analyzed during each device activation setting

Time frame: 1 - 1.25 hour

Change in respiratory rate during baroreflex activation therapy

Change in respiratory variables will be analyzed during the aforementioned time frame in which we will program several device activation settings.

Time frame: 1 - 1.25 hour

Change in expiration time during baroreflex activation therapy

Change in respiratory variables will be analyzed during the aforementioned time frame in which we will program several device activation settings.

Time frame: 1 - 1.25 hour

Change in heart rate during baroreflex activation therapy

The change in cardiovascular variables will be analyzed during each device activation setting

Time frame: 1 - 1.25 hour

Change in peripheral vascular resistance during baroreflex activation therapy

The change in cardiovascular variables will be analyzed during each device activation setting

Time frame: 1 - 1.25 hour

Change in forced expiratory volume-1 second (FEV1) before and after turning off the device

Time frame: 2 hours

Effect Baroreflex Activation Therapy on the Carotid Body

Overview

Conditions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts