Active clinical trials for "Hypertension"

The investigators want to test the hypothesis that patients with chronic renal disease have a poorer ability to preserve water after being thirsty and a poorer ability to excrete water after a load of fluid. They presume that these abilities become poorer when renal insufficiency progresses. The investigators further hypothesize that patients with hypertension also have a decreased ability to concentrate and dilute urine.

In the present study, we assessed the relation between diastolic dysfunction and myocardial fibrosis in hypertensive patients without diabetes mellitus. A total of 20 medically treated ambulatory non-diabetic hypertensive patients with normal left ventricular (LV) systolic function were enrolled into this study. Myocardial fibrosis was evaluated by serum concentrations of amino-terminal propeptides of type I and III procollagen (PINP and PIIINP). All patients underwent examinations of diastolic function by echocardiography and technetium-99m (99mTc) radionuclide ventriculography. There were 8 patients with PINP ≦53 μg/l (group 1) and 12 patients with PINP >53 μg/l (group 2). Patients in group 2 had significantly lower LV peak filling rate (PFR; 3.2 ± 0.3 vs. 2.5 ± 0.2 end-diastolic volume/s) and shorter time to PFR ( 257 ± 41 vs. 174 ± 22 ms). Besides, the group 2 patients also had lower right ventricle PFR (1.9 ± 0.2 vs. 1.5 ± 0.1 end-diastolic volume/s) and shorter time to PFR ( 221 ± 29 vs. 154 ± 29 ms). Echocardiographic parameters for LV diastolic dysfunction (E/A ratio of mitral flow, deceleration time of E flow, velocities of pulmonary venous flow [retrograde A wave, systolic /diastolic velocity ratio], isovolumetric relaxation time, Tei index) were all comparable between two groups. In multiple regression analysis, LV time to peak filling rate was the only parameter that independently predicted serum PINP level (p<0.05). In conclusion, elevated serum PINP level reflected LV diastolic dysfunction in hypertensive patients without diabetes.

To investigate the mechanisms of white coat hypertension and study it further as a risk factor for heart damage.

The overall objective of this proposal is to examine the contribution of changes in total body fat, enhancement in insulin-mediated vasodilatation and enhancement in endothelium-derived nitric oxide production to the improvements in metabolic insulin action. In addition, the study will track whether these improvements are related to changes in blood pressure.

To investigate familial patterns of hypertension and related cardiovascular (CV) risk factors in the United States and Nigeria.

To examine a school-based population of children for maturational changes in blood pressure and cardiac structures.

This study will investigate congenital or developmental eye abnormalities that affect the iris, cornea and lens, and are usually accompanied by elevated pressure within the eye. These disorders can cause vision loss, and the increased eye pressure can lead to glaucoma, a condition that may also cause loss of eyesight. Patients with eye anterior chamber eye disease, such as Axenfeld's syndrome, Rieger's anomaly, Peter's anomaly, iridocorneal endothelial syndrome, megalocornea, ocular hypertension, and others, are eligible for this study. Participants will have a medical examination, family history, and comprehensive eye examination. Tests and procedures may include photographs of the cornea, iris, and the structure through which fluid that normally circulates behind the cornea drains out of the eye. Some patients may undergo indentation tonography to measure how easily this fluid drains. In this procedure, the patient lies on an examination table and both eyes are numbed with eye drops. A small instrument (tonometer) is placed on the surface of one eye, and with the other eye, the patient looks at an overhead light. Other tests may include photographs of the back of the eye and ultrasound imaging of the structures of the eye. A blood sample may be drawn to study the genetic disorder responsible for the disease. Patients will have follow-up examinations every 6 months for the duration of the study. Medical or surgical therapy will be recommended, as appropriate, for patients who develop elevated eye pressure or vision loss.

Blood pressure reduction and control are associated with reduced risk of stroke and cardiovascular disease. There is evidence that ambulatory blood pressure monitoring (ABPM) results more accurately reflect the risk of cardiovascular events than do office measurements of blood pressure. New international guidelines recognize the importance of ABPM which has an important and growing role in the diagnosis and in guiding antihypertensive therapy. In 2011 in the United Kingdom, the National Institute for Health and Care Excellence (NICE) recommended that ABPM be performed on all patients with suspected hypertension to confirm the diagnosis and reduce unnecessary treatment in people who do not have true hypertension. The aim of this observational study is to describe the utility of ABPM generally and specifically in the management of hypertension by Cardiologists in the Algerian context.

A prospective study of the use of two novel MRI techniques (oxygen-enhanced and fourier decomposition MRI) in the initial diagnosis and follow-up of patients with Pulmonary Hypertension. The investigators believe these techniques may present a novel set of imaging biomarkers that may be used for risk stratification, prediction of treatment response and longitudinal disease monitoring. The reserach MRI is in addition to standard of care and will not affect treatment decisions.

The Tunisian Society of Cardiology and Cardiovascular Surgery (STCCCV) proposes to coordinate a national, observational, cross-sectional and multicenter survey carried out during one month. The main objective of the survey is to describe the blood pressure and cardiovascular risk profile of the hypertensive patient in Tunisia. This survey will allow us to have a generalized and updated view of the tunisian hypertensive patient in order to optimize treatment and to know the degree of adherence of practitioners to international recommendations in the care of the hypertension in Tunisia.