View clinical trials related to Ischemia.
Filter by:Coronary artery disease (CAD, coronary heart disease) is the leading cause of death in the U.S., causing 1 in 5 deaths in 2005. The current method for diagnosing coronary artery disease that is considered most accurate is coronary angiography however it involves risk and radiation. Alternatively nuclear imaging test and MRI stress test only permits the semi qualitative analysis of the myocardial perfusion images. In this proposal the investigators will develop a means to calculate Coronary Flow Reserve (CFR) using the MRI. the investigators approach has the potential to reduce mortality from myocardial infarction by effecting a change in the patient management paradigm. Absolute quantification of myocardial perfusion will detect coronary stenosis and CAD in patients with more accuracy than the semi-quantitative or qualitative analysis of perfusion images. Measurement of Coronary Flow Reserve is important for the following reasons: decrease of coronary flow reserve has been identified as a first effect of CAD; it provides an objective measure of treatment efficacy. The purpose of this study is to compare images from nuclear stress test and/or coronary angiography with Magnetic Resonance Imaging (MRI) that will evaluate subjects with coronary artery disease calculating myocardial blood flow using a novel MRI technique combined to an extracellular Gadolinium-based contrast agent and stressor agent
This trial will enroll patients that have been diagnosed with a transient ischemic attack (TIA) or minor stroke that has occurred within the past 12 hours. Anyone diagnosed with a minor stroke faces the possibility of long-term disability and even death, regardless of treatment. Stroke symptoms such as weakness, difficulty speaking and paralysis may improve or worsen over the hours or days immediately following a stroke. The purpose of this research trial is to study the effects of a clot-dissolving drug, tenecteplase (TNK-tPA), as a treatment for patients who arrive within twelve hours from stroke onset. This study is attempting to see if TNK-tPA given through a vein in the arm (intravenous) to patients is a safe treatment for stroke patients. Neither the safety nor the effectiveness of this treatment has been proven yet. This trial will be conducted at several site in Canada. Dr Michael Hill and Dr. Shelagh Coutts are the Principal Investigators of this trial, coordinated at the University of Calgary, Foothills Medical Centre.
This is a pilot study to test feasibility and safety of collection, preparation and infusion of a baby's own (autologous) umbilical cord blood during the first 3 days of age if the baby is born with signs of brain injury. The cord blood used is fresh (not frozen and then thawed).
The objectives of this study are to compare directly conventional balloon angioplasty alone versus. balloon angioplasty with routine stenting - that is, to determine whether angioplasty with self-expanding stent is superior to conventional balloon angioplasty - in the infrapopliteal arterial occlusive lesions of critical limb ischemia patients by collecting and analyzing the cases of each patient group in a prospective multicenter randomized clinical trial, and to clarify main factors affecting mid- and long-term clinical effects of angioplasty with self-expanding stent in the infrapopliteal arteries. Hypothesis: Balloon PTA followed by routine stenting with self-expanding nitinol stent in critical limb ischemia patients with infrapopliteal arterial occlusive lesions is superior to conventional PTA in the aspect of vascular restenosis rate.
The purpose of the study is to determine if a new blood test can help the doctor determine if there is brain injury or ischemia. Ischemia occurs when not enough oxygen gets to the brain. In this study the investigators are analyzing your blood for a new test that might help doctors decide if symptoms are from a neurologic problem.
The purpose of the study is to assess the efficacy of a new serotonin-norepinephrine reuptake inhibitor (SNRI) nin functional recovery after ischemic stroke.
The release of tourniquet produces reactive oxygen species which can cause injury. Propofol is chemically similar to phenol-based free radical scavengers. Plasma total antioxidant capacity is a well-established marker of the overall protective effect of antioxidants in body fluids.The aim of the study is to investigate the effects of propofol on ischemia-reperfusion injury in total knee arthroplasty (TKA).
The investigators are trying to evaluate the clinical effect of remote ischemic postconditioning on liver graft function and postoperative renal function in subjects undergoing living-donor liver transplantation.
Coronary artery disease (CAD) is the leading cause of morbidity and mortality in industrialized countries despite advances in medical, interventional, and surgical revascularization therapies. In both, acute myocardial infarction (AMI) and chronic stable disease, standard therapeutic approaches may fail to restore tissue perfusion. Indeed, a substantial number of chronic CAD patients may not be amenable to standard revascularization therapies or percutaneous coronary intervention (PCI) may fail to restore coronary artery patency following an acute vessel occlusion (no-reflow phenomenon, microvascular obstruction). As a consequence, the long pursued strategy of augmenting myocardial perfusion by diverting blood from the coronary venous system to an ischemic region (venous retroperfusion) has again gained attention during recent years. Occlusion of the coronary sinus (CSO) was introduced to provide retroperfusion by transient augmentation of coronary venous pressure. Different devices using CSO have been invented and evaluated in animal models and small clinical trials, e.g. intermittent CSO (ICSO) and pressure-controlled intermittent CSO (PICSO) which seem to be effective for myocardial salvage. However, they are not yet employed in clinical routine, and importantly, the exact underlying mechanisms by which retroperfusion due to CSO may reduce myocardial ischemia are not yet understood. As "natural bypasses", coronary collaterals are anastomoses without an intervening capillary bed between portions of the same coronary artery or between different coronary arteries that represent an alternative source of blood supply to a myocardial area jeopardized by ischemia. Collaterals of the heart can be assessed quantitatively by coronary pressure measurements, which have become the gold standard (collateral flow index, CFI=[Poccl-CVP]/[Pao-CVP]). Theoretically, augmentation of coronary sinus pressure by CSO with an increase of venous backflow reaches the upstream collateral circulation, which in turn could lead to improved collateral flow from non-ischemic area(s) to an occluded, ischemic myocardial region by upstream flow diversion. On the other hand, when considering the formula to calculate pressure-derived CFI, it seems that augmentation of coronary back pressure would rather impair collateral flow (since central venous pressure is coronary sinus pressure). However, the regional effect of a global increase in coronary sinus pressure is unlikely to be as uniform as the above formula implies, i.e., the response is more pronounced in some than in other vascular territories. In experimental studies using dogs (with abundant collaterals), elevation of coronary sinus pressure caused an augmentation of regional myocardial blood flow in the collateralized area. In contrast, when ICSO was performed in pigs (which possess no preformed collaterals), it increased the pressure distal of an occluded LAD but did not improve blood flow or left ventricular function. In conclusion, experimental studies and pathophysiologic considerations suggest a necessary role of the collateral circulation for the beneficial effects of coronary sinus occlusion (CSO) observed in animals and humans; however, no clinical data are available so far on the effect of CSO on myocardial ischemia in the presence of varying collateral flow. Study hypotheses 1. CSO decreases intra-coronary ECG ST-segment elevation during a 2-minute coronary occlusion. 2. The decrease in occlusive intra-coronary ECG ST elevation during CSO is directly proportional to CFI. 3. Coronary sinus oxygen saturation during coronary occlusion with CSO is directly proportional to CFI.
This present research project intends to collect five quantitative test series: - perimetric examination using static stimuli, assessing the entire (80 degree) visual field with a fast thresholding algorithm (GATE) [Schiefer 2008] to know the extent/ magnitude of the visual field defect and its variability within the cohort and over time - D-BCVA, using FrACT [Bach 2007] and EDTRS chart [Ferris 1982] - RAPD (using swinging flashlight test). - IOP (using applanation tonometer) - RNFT and RNFV using Spectralis OCT (star scan, ring scan 2,8 mm, and volume scan) Optic disk morphology will be documented by fundus photography. This assessment of the above-mentioned data is needed in order to allow for estimation of the spontaneous course / fluctuation of the (quantified) functional and morphometric parameters of the N-AION patients during the follow-up period. This is essential for the estimation of the sample size of the subsequently intended SINN study, that is intended to compare different therapeutic strategies in N-AION patients.