View clinical trials related to Blood Pressure.
Filter by:Ephedrine is commonly clinically vasoactive drugs, which can constrict blood vessels and increase blood pressure. Ephedrine can not only stimulate α receptors, but also β receptors, that's to say, it can increase heart rate, stroke volume, and cardiac output, but it also can decrease the level of systemic vascular resistance. This research aims to observe the short-term vasodilator effect of diffierent doses of ephedrine used in elderly patients under general anesthesia in clinical practice, and analyze the main reasons for this phenomenon and take preventive actions to minimize the possibility of further lowering of blood pressure to provide references for clinical rational use of drugs.
The purpose of this study is to examine the hypothesize that 4 weeks of sympathetic nerve activity (SNA) inhibition (oral clonidine) will cause a significant reduction in circulating blood concentrations and endothelial cell expression of inflammatory markers (e.g., TNF-α, IL-6). Our study is a prospective study using a randomized, double-blinded design to test 4 weeks of SNA blockade (oral clonidine) compared with a BP-lowering control condition (diuretic, hydrochlorothiazide) or a placebo.
During major surgery, it is recommended to monitor invasive arterial blood pressure and cardiac output (CO) during hemodynamic interventions (fluid challenge or vasopressors). Esophageal Doppler is currently considered as the reference method for monitoring cardiac output in the operating room. The PRAM method (pressure recording analytical method) with the MostCareUp monitor (Vytech, Padova, Italy) and the LTIA method (long time interval analysis) allow cardiac output estimation derived from non-calibrated arterial pressure waveform analysis. Few studies have looked at relative changes in cardiac output during hemodynamic intervention with these two methods. The aim of this study is to compare the relative changes in cardiac output during hemodynamic interventions as measured using PRAM and LTIA methods, compared to esophageal Doppler.
More than 80% of individuals with chronic kidney disease have concomitant hypertension and the majority fail to achieve blood pressure control <130/80 mmHg, leading to high risk of cardiovascular diseases and end-stage kidney disease. A stepwise combination of lifestyle modifications and drug therapy is recommended to lower blood pressure; however, adherence to time-intensive lifestyle interventions such as aerobic exercise in patients with chronic kidney disease is poor. This clinical trial seeks to establish the efficacy of high-resistance inspiratory muscle strength training, a novel time-efficient lifestyle intervention, for lowering systolic blood pressure and improving endothelial function in midlife and older adults with moderate-to-severe chronic kidney disease and inadequately controlled hypertension, and to use innovate translational assessments to understand the mechanisms involved.
The treatments will be: 1) norepinephrine or phenylephrine infusion to maintain intraoperative MAP ≥85 mmHg (tight pressure management); or, 2) routine intraoperative blood pressure management (routine pressure management).
Above-normal systolic blood pressure (SBP), defined as SBP >/= 120 mmHg, is the major modifiable risk factor for cardiovascular disease, stroke, cognitive decline/dementia, and other chronic health problems. Despite the availability of treatments to lower SBP, over 75 percent of adults with above-normal SBP fail to control BP, which has led to a nearly 50 percent increase in the number of deaths attributable to BP over the past decade. Therefore, above-normal SBP is a major public health burden. - Greater than 65 percent of adults 50 years of age and older have above-normal SBP. The number of adults age 50 years and older is rapidly increasing, predicting a continued increase in above-normal SBP driven morbidity and mortality in the absence of effective treatment strategies. This makes developing novel SBP-lowering therapies an urgent biomedical research priority. - Increasing SBP is closely linked to vascular dysfunction, observable as impaired endothelial function, increased large-elastic artery stiffness, and impaired cerebrovascular function. Declines in these functions play a large role in the increased risk of chronic disease associated with above-normal SBP. The primary mechanism responsible for SBP-induced vascular dysfunction is thought to be oxidative stress-associated inhibition of nitric oxide bioavailability. Therefore, to have the largest biomedical impact, new SBP-lowering therapies should also improve vascular function by decreasing oxidative stress. - Healthy lifestyle practices, such as conventional aerobic exercise, maintaining a healthy diet, or reducing sodium intake, are all first-line strategies to lower SBP. Importantly, these lifestyle practices also improve vascular function, in large part by reducing oxidative stress. However, adherence to healthy lifestyle practices is poor, with adherence to guidelines generally between 20 to 40 percent in adult Americans. The greatest reported barrier to meeting healthy lifestyle guidelines is lack of time. Therefore, time-efficient interventions have great promise for promoting adherence, reducing SBP, and improving other physiological functions. - High-resistance inspiratory muscle strength training (IMST) is a time-efficient (5 minutes per session) lifestyle intervention consisting of 30 inspiratory maneuvers performed against a high resistance. Preliminary data suggest 6-weeks of IMST performed 6 days/week reduces SBP by 9 mmHg in adults with above-normal SBP (i.e., greater than 120 mmHg) at baseline. Importantly, this reduction in SBP is equal to or greater than the reduction in blood pressure typically achieved with time- and effort-intensive healthy lifestyle strategies like conventional aerobic exercise. However, these results need to be confirmed in an appropriately powered clinical trial with a longer, guideline-based treatment duration. Furthermore, the influence of IMST on functions impaired by above-normal SBP (endothelial, cerebrovascular, cognitive) needs to be determined, as do the mechanisms through which IMST exerts beneficial effects. - Accordingly, we will conduct a randomized, blinded, sham-controlled, parallel group design clinical trial to assess the efficacy of 3-months of IMST (75 percent maximal inspiratory pressure) vs. brisk walking (40-60% heart rate reserve; an established healthy lifestyle strategy) for lowering SBP and improving endothelial, cerebrovascular, and cognitive function in adults age 50 years and older with above-normal SBP. I hypothesize IMST will lower SBP and improve endothelial function by decreasing oxidative stress and increasing nitric oxide bioavailability. I also hypothesize IMST will improve cerebrovascular and cognitive function, and that these improvements will be related to reductions in SBP and improvements in endothelial function. I also expect adherence to the intervention to be excellent (over 80 percent of all training sessions completed at the appropriate intensity). - To test my hypothesis, I will recruit 102 adults age 50 years and older who have SBP >/= 120 mmHg. Subjects will undergo baseline testing for casual (resting) SBP, 24-hour ambulatory SBP, endothelial function, arterial stiffness, cognitive function, and cerebrovascular function. Innovative mechanistic probes including pharmaco-dissection with vitamin C, analysis of biopsied endothelial cells, and high-throughput metabolomics, will be performed to assess oxidative stress and nitric oxide bioavailability at baseline. - After baseline testing, subjects will be randomized to perform either 3-months of high-resistance IMST or brisk walking. Subjects will train 6 days/week with one training session supervised in the laboratory and the other 5 performed unsupervised at home. Following 3 months of training, subjects will redo all the tests that were done during baseline testing to assess training-induced changes in SBP, physiological functions, and underlying mechanisms.
The purpose of our study is to understand the extent to which the blood vessels are affected by glucose and fat (lipids) in lean healthy adults and if these changes in the blood vessels contribute to the development of high blood pressure.
Hypertension is a progressive cardiovascular syndrome caused by multiple causes, which can lead to changes in the function and structure of the heart and blood vessels. It is the leading risk factor of cardiovascular disease. Berberine (BBR) hydrochloride is an isoquinoline alkaloid (chemical formula: C20H18NO4) extracted from traditional Chinese herb Coptis chinensis. It has been widely used to treat diarrhea and enteritis for hundreds of years in China. BBR has extremely high clinical application value. It is an over-the-counter drug with low price, good safety and few adverse reactions in China. We found that Berberine (BBR) hydrochloride tablets have a hypotensive effect in clinical practice. However, there are few clinical studies on the treatment of hypertensive patients with BBR tablets. In addition, the clinical dosage of BBR tablets is not uniform, and its molecular mechanism is still unclear. In order to further evaluate the clinical efficacy of BBR in reducing blood pressure and improving vascular endothelial injury, we carried out this clinical trial of drug intervention for hypertensive population. After signed the informed consent, the subjects are assigned to the lifestyle intervention group (CON) and berberine hydrochloride group (BBR). The berberine hydrochloride group (BBR) take berberine hydrochloride tablets (0.4g, 3 times/day, 3 months) . We will follow up blood pressure and vascular endothelial function in 1 month and 3 months after taking the medicine.
The aim of this study is to investigate the role of the 677C→T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene on blood pressure (BP) during pregnancy, and to examine the effect of intervention with riboflavin, alone or in combination with 5-methyltetrahydrofolate (5-MTHF), as a non-drug approach for managing BP in pregnancy in women with the variant TT genotype. In addition, we aim to examine the effect of maternal supplementation with riboflavin, alone or combined with 5-MTHF, on BP in the offspring in early infancy. Study design: A double-blind randomized controlled trial in pregnant women will be conducted. Women with a singleton pregnancy who are in their first trimester will be recruited from antenatal clinics in Northern Ireland and the Republic of Ireland. Women interested in the study will provide informed consent, complete a screening questionnaire and will provide a buccal swab to collect DNA to screen for the MTHFR 677C→T polymorphism. Women with multiple pregnancies, a previous NTD-affected pregnancy and those who are taking medication interfering with B-vitamin metabolism will be excluded from participation in the study. At approximately the 16th gestational week (GW), those with the variant TT genotype and age-matched heterozygous women (CT genotype) will be randomised to receive riboflavin (5 mg/day) alone, or in combination with 5-MTHF (400µg/day), or placebo, until the end of pregnancy. A non-fasting blood sample will be collected for biomarker assessment of B-vitamin status and other relevant variables from each participant before intervention and at the 36th GW. At the same time points, anthropometric and BP measurements will be taken. Women will also complete a health and lifestyle questionnaire and a 4-day dietary record. Samples of cord blood, umbilical cord and placenta will be collected after delivery and anthropometric parameters of the newborns will be retrieved postpartum. Maternal and infant BP will be measured 2-4 months after birth. In parallel with the intervention trial, age-matched pregnant women who do not carry the variant gene (CC genotype) and have not been randomized to treatment, will be monitored in order to control for any changes associated with normal pregnancy in the study outcome measurements. In the pilot phase, the feasibility and acceptability of the study procedures and treatment will be evaluated for clarification of the sample size and refinement of the study protocol.
Hemodialysis vascular access dysfunction continues to be a major source of morbidity and mortality in patients with ESRD. Thrombosis is the most common cause of secondary vascular access failure Although intimal hyperplasia at the outflow vein is the most common cause of thrombosis, 20-40% of thrombosis may develop secondary without underlying anatomic abnormalities. Low-flow states secondary to low BP have been proposed to precipitate access thrombosis. In previous studies, lower pre- and post- dialysis SBP are associated with a higher rate of access thrombosis. Nonetheless, high blood pressure is also a well-known risk factor for arteriosclerosis, intimal hyperplasia, and thrombotic vascular events. In dialysis patients, the relation between blood pressure and thrombosis seems to be more complex, and few studies have delineated the effect of blood pressure in a systematic manner. In addition to the static component of blood pressure, blood pressure variability (BPV) is increasingly accepted as a novel risk factors for vascular disease. BPV is categorized as either long or short term. In dialysis patients, long-term BPV is typically defined on the basis of BP measurements taken at the start of hemodialysis (inter-dialysis BPV); short-term BPV is usually considered in terms of variability during hemodialysis (intra-dialysis BPV). BP variability is increased in ESRD patients and is associated with adverse outcomes. To the best of our knowledge, only one study by Cheung et al focused on intra-dialytic BPV, which found intradialytic hypotension to be a risk factor for access thrombosis. Nonetheless, access thrombotic events rarely occur during the dialysis session. It remained unclear that if inter-dialysis BPV is a more relevant factor for access thrombosis. Answer to this question is of clinical significance because the optimal BP target after PTA remained unknown. In this study, we aimed to investigate the effect of BP variability on the outcomes of hemodialysis vascular access, major cardiovascular events in maintenance hemodialysis patients. We also aimed to evaluate the determinants of BPV in hemodialysis patients, including medication, frailty, fluid status and autonomic function. The impact of autonomic function and frailty on the outcomes of vascular access and cardiovascular events will be evaluated as well.