View clinical trials related to Pulmonary Artery Hypertension.
Filter by:This observational study is being done to understand why people with scleroderma can develop pulmonary arterial hypertension (high blood pressure in the lungs, abbreviated PAH) and a weak heart muscle (heart failure). The study will also help the investigators understand why people with PAH from an unknown cause (called idiopathic PAH, or IPAH) can also develop a weakened heart muscle. The response of the right side of the heart or right ventricle (RV) to standard PAH therapy in scleroderma-associated PAH and in IPAH will be assessed. Blood and tissue samples will be collected from research participants during participants' normal standard of care procedures. People with scleroderma-associated PAH or idiopathic cause (IPAH) who need a right heart catheterization may join this study.
In pulmonary arterial hypertension (PAH), progressive pulmonary vascular remodeling leads to supraphysiologic right ventricular (RV) afterload. Pharmacologic trials have shown that aggressive upfront treatment reversing pulmonary vascular remodeling successfully increases RV function and improves survival. To date, however, there are no proven treatments that target RV contractile function. Echocardiographic studies of RV dysfunction in the setting of pressure overload have demonstrated intra and interventricular dyssynchrony even in the absence of overt right bundle branch block (RBBB). Electrophysiologic studies of patients with chronic thromboembolic disease (CTEPH) at the time of pulmonary endarterectomy have shown prolongation of action potential and slowed conduction in the right ventricle which has correlated with echocardiographic measures of dyssynchrony. Cardiac MRI measures of RV strain in patients with PAH demonstrated simultaneous initiation of RV and left ventricular (LV) contraction, but delayed peak RV strain suggesting that interventricular dyssynchrony is a mechanical rather than electrical phenomenon. Prior studies of RV dysfunction in an animal model, computer model, congenital heart disease, and CTEPH have suggested acute hemodynamic benefits of RV pacing. However, RV pacing has not been studied in patients with PAH. Furthermore, it remains unclear if pacing particular regions of the RV can achieve a hemodynamic benefit and what cost this hemodynamic improvement may incur with regards to myocardial energetics and wall stress. Therefore, the investigators propose to examine RV electrical activation in PAH, map the area of latest activation, and then evaluate the hemodynamic and energetic effects of RV pacing in these patients.
The objective of the present study is to assess blood coagulation disorders in patients with Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension. The investigators aim to evaluate any possible coagulation abnormalities related to the patients' primary disease and any possible effects the pulmonary hypertension- specific therapy may have on hemostasis.
Background: A heart catheterization is a diagnostic heart procedure used to measure pressures and take pictures of the blood flow through the heart chambers. Magnetic resonance imaging (MRI) fluoroscopy shows continuous pictures of the heart chambers that doctors can watch while they work. Researchers want to test this procedure with catheterization tools routinely used in x-ray catheterization called guidewires. Guidewires will help move the heart catheter through the different heart chambers. Guidewires are usually considered unsafe during MRI because MRI can cause a guidewire to heat while inside the blood vessels and heart. Researchers are testing special low energy MRI settings that allow certain guidewires to be used during MRI catheterization without heating. Using these guidewires during MRI may help to decrease the amount of time you are in the MRI scanner, and the overall time the MRI catheterization procedure takes. Objectives: To test if certain MRI settings make it safe to use a guidewire during MRI fluoroscopy. Eligibility: Adults 18 and older whose doctors have recommended right heart catheterization. Design: Researchers will screen participants by reviewing their lab results and questionnaire answers. Participants may give 4 blood samples. Participants will be sedated. They will have a tube (catheter) placed in the groin, arm, or neck if they don t already have one. Patches on the skin will monitor heart rhythm. Special antennas, covered in pads, will be placed against the body. Participants will lie flat on a table that slides in and out of the MRI scanner as it makes pictures. Participants will get earplugs for the loud knocking noise. They can talk on an intercom. They will be inside the scanner for up to 2 hours. They can ask to stop at any time. During a heart catheterization, catheters will be inserted through the tubes already in place. The catheters are guided by MRI fluoroscopy into the chambers of the heart and vessels. The guidewire will help position the catheter. ...
Many control mechanisms exist which successfully match the supply of blood with the metabolic demand of various tissues under wide-ranging conditions. One primary regulator of vasomotion and thus perfusion to the muscle tissue is the host of chemical factors originating from the vascular endothelium and the muscle tissue, which collectively sets the level of vascular tone. With advancing age and in many disease states, deleterious adaptations in the production and sensitivity of these vasodilator and vasoconstrictor substances may be observed, leading to a reduction in skeletal muscle blood flow and compromised perfusion to the muscle tissue. Adequate perfusion is particularly important during exercise to meet the increased metabolic demand of the exercising tissue, and thus any condition that reduces tissue perfusion may limit the capacity for physical activity. As it is now well established that regular physical activity is a key component in maintaining cardiovascular health with advancing age, there is a clear need for further studies in populations where vascular dysfunction is compromised, with the goal of identifying the mechanisms responsible for the dysfunction and exploring whether these maladaptations may be remediable. Thus, to better understand the etiology of these vascular adaptations in health and disease, the current proposal is designed to study changes in vascular function with advancing age, and also examine peripheral vascular changes in patients suffering from chronic obstructive pulmonary disease (COPD), Sepsis, Pulmonary Hypertension, and cardiovascular disease. While there are clearly a host of vasoactive substances which collectively act to govern vasoconstriction both at rest and during exercise, four specific pathways that may be implicated have been identified in these populations: Angiotensin-II (ANG-II), Endothelin-1 (ET-1), Nitric Oxide (NO), and oxidative stress.
Pulmonary artery hypertension (PAH) is a chronic and progressive disease that affects 15 persons per million. Although current therapy has improve disease prognosis, PAH still has a poor survival, with a median survival of 2.8 years after diagnosis. In the last few years new key elements in PAH pathogenesis have been discovered, such as the role of metabolism in disease onset and progression. In fact, PAH pulmonary smooth muscle cells switch into a glycolytic phenotype which resembles the metabolism of cancer cells. The investigators hypothesis is that "fatty acid oxidation inhibition reverts the PAH adverse phenotype by restoring mitochondrial function and morphology, decreasing proliferation and restoring apoptosis susceptibility in pulmonary smooth muscle cells "
Patients with hemolytic disorders (e.g. sickle cell anemia or thalassemia) are known to develop pulmonary hypertension. Hemolysis is where red blood cells are destroyed and their contents released into the circulation. It is thought that these red-cell contents cause constriction and thrombosis of the blood vessels in the lungs. Conversely, it is possible that patients with pulmonary hypertension have hemolysis. In this study we will be drawing blood from a range of patients and normal controls for a panel of blood tests related to hemolysis.