89 resultados para CCD PHOTOMETRY
Resumo:
Two young women with angiographically normal coronary arteries suffered an acute myocardial infarction. Both were found to have a patent foramen ovale (PFO), the likely pathway of a paradoxical embolus causing the infarction. The PFOs were diagnosed and closed percutaneously with an Amplatzer PFO Occluder during the emergency coronary angiography.
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Currently, observations of space debris are primarily performed with ground-based sensors. These sensors have a detection limit at some centimetres diameter for objects in Low Earth Orbit (LEO) and at about two decimetres diameter for objects in Geostationary Orbit (GEO). The few space-based debris observations stem mainly from in-situ measurements and from the analysis of returned spacecraft surfaces. Both provide information about mostly sub-millimetre-sized debris particles. As a consequence the population of centimetre- and millimetre-sized debris objects remains poorly understood. The development, validation and improvement of debris reference models drive the need for measurements covering the whole diameter range. In 2003 the European Space Agency (ESA) initiated a study entitled “Space-Based Optical Observation of Space Debris”. The first tasks of the study were to define user requirements and to develop an observation strategy for a space-based instrument capable of observing uncatalogued millimetre-sized debris objects. Only passive optical observations were considered, focussing on mission concepts for the LEO, and GEO regions respectively. Starting from the requirements and the observation strategy, an instrument system architecture and an associated operations concept have been elaborated. The instrument system architecture covers the telescope, camera and onboard processing electronics. The proposed telescope is a folded Schmidt design, characterised by a 20 cm aperture and a large field of view of 6°. The camera design is based on the use of either a frame-transfer charge coupled device (CCD), or on a cooled hybrid sensor with fast read-out. A four megapixel sensor is foreseen. For the onboard processing, a scalable architecture has been selected. Performance simulations have been executed for the system as designed, focussing on the orbit determination of observed debris particles, and on the analysis of the object detection algorithms. In this paper we present some of the main results of the study. A short overview of the user requirements and observation strategy is given. The architectural design of the instrument is discussed, and the main tradeoffs are outlined. An insight into the results of the performance simulations is provided.
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AIM: To investigate the outcome of primary percutaneous coronary interventions (PCI) in elderly patients (>/=>/=75 years) with ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS: Between 1995 and 2003, a total of 319 consecutive patients with acute ST-elevation myocardial infarction presenting within 6-12 hr after onset of symptoms were prospectively enrolled in a registry. Of 296 patients undergoing primary PCI, 40 patients were >/=>/=75 years old (group A) and 256 patients younger than 75 years (group B). Elderly patients presented with a lower ejection fraction (49 +/- 14% vs. 53 +/- 13%, P = 0.046) and a higher number of cardiovascular risk factors. PCI success was achieved in 80% (group A) and 91% (group B, P = 0.031), respectively with comparable door-to-balloon times (87 +/- 49 and 95 +/- 79 min, P = ns). Periprocedural complications in both groups were low and major adverse cardiac events (death, myocardial infarction, target vessel revascularization and cardiac rehospitalization) after 6 months amounted to 23% (group A) and 20% (group B, P = ns), respectively. CONCLUSIONS: Clinical outcome of elderly patients (>/=>/=75 years) with acute STEMI is favorable and comparable with the middle-aged population. However, procedural success was significantly lower in elderly (80%) compared to younger patients (90%). Acute percutaneous coronary intervention appears to be safe and not associated with higher periprocedural complications, in elderly patients.
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We review the case of a 48-year-old woman who underwent elective percutaneous patent foramen ovale closure following successive renal and myocardial infarction with normal renal and coronary arteries, probably as a consequence of paradoxical emboli.
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BACKGROUND: The value of incidental coronary angiography during percutaneous shunt closure to screen for asymptomatic coronary artery disease (CAD) is unknown. METHODS: On the occasion of percutaneous closure of patent foramen ovale (PFO), incidental coronary angiography routinely offered to men >40 and women >50 years, or younger patients with particular risk patterns, was performed in 575 patients (64% men, mean age 55 +/- 10 years, mean 1.5 +/- 1.1 cardiovascular risk factors) without overt history, signs, or symptoms of CAD. RESULTS: CAD was found in 164 patients (29%); 53 (9%) had >or=50% diameter stenoses. Thirty patients (5%) had one-vessel, 13 (2%) two-vessel, and 10 (2%) three-vessel disease. Patients with CAD (n = 164) were older (60 +/- 9 vs. 53 +/- 10 years; P < 0.0001), more frequently male (76% vs. 59%; P = 0.0002), and had a higher body mass index (26.5 +/- 4.0 vs. 25.4 +/- 4.6; P = 0.006) and more cardiovascular risk factors (2.0 +/- 1.1 vs. 1.2 +/- 1.0; P < 0.0001). There were six procedural complications (1%). Two were unequivocally related to coronary angiography: one minor stroke (diplopia), and one iatrogenic dissection of the right coronary ostium requiring stenting. Furthermore, four arteriovenous fistulae at the puncture site requiring elective surgical closure were possibly related to coronary angiography. Forty-five patients (8% of total) underwent percutaneous (n = 43) or surgical (n = 2) revascularization. CONCLUSIONS: In selected asymptomatic patients referred for percutaneous PFO closure, incidental coronary angiography discloses a rather high prevalence of clinically unsuspected CAD. These findings are relevant not only for timely revascularization but also for maintenance of long-term antiplatelet therapy beyond the few months recommended after PFO closure.
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Migraine is a recurrent disabling disorder predominantly affecting middle-aged women. Migraine occurs with or without aura symptoms. Several studies have shown an increased prevalence of right-to-left shunts (RLSs) in migraine with aura. The overwhelming majority of these shunts were due to a patent foramen ovale (PFO). Furthermore, migraine with aura is more prevalent in clinical entities associated with a RLS, e.g. cryptogenic stroke, decompression illness in divers, or in patients with hereditary hemorrhagic teleangiectasia and pulmonary arteriovenous fistulas. Retrospective studies have consistently shown that shunt closure was associated with a significant reduction in migraine frequency. Its beneficial effect seemed to exceed the efficacy of conventional migraine therapy. Several randomized clinical trials to prospectively assess the benefit of shunt closure in migraine patients have been initiated. The only one completed, the MIST trial (Migraine Intervention with STARFLEX Technology), showed a significant reduction of migraine with aura after device implantation, compared with controls. However, the benefit of PFO closure was more modest than expected. This review recapitulates the current data regarding PFO closure and migraine with aura and summarizes in brief the current knowledge regarding migraine pathophysiology and the link to a RLS.
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Right atrial perforation can lead to tamponade and death. Closure devices are used for sealing of shunts in the heart. We describe an indwelling catheter that caused perforation of the right atrium and was treated with a percutaneous closure device.
Resumo:
BACKGROUND: Little is known on the performance of newly initiated carotid artery stenting (CAS) programs. The safety of the procedure is being questioned following the publication of the EVA-3S trial, a study criticized for the limited interventional experience required to enroll patients. METHODS: Within a newly started academic CAS program, patient data and outcomes were collected prospectively. The outcomes of the first 100 consecutive patients treated are reported. A CAS-fellowship-trained interventionalist was involved in all procedures. All patients underwent clinical assessment by a neurologist before and after the procedure, and serial ECG and cardiac enzymes were routinely obtained. Primary outcome measures included 30-day major adverse events (MAE), defined as death, stroke, or myocardial infarction, while on follow-up deaths and ipsilateral strokes were added. RESULTS: Between July 2003 and November 2006, 92 patients had a single internal carotid artery treated, while 7 underwent staged bilateral CAS. In one patient, the procedure was aborted prior to lesion treatment. The 30-day MAE rate per procedure was 1.9% (one major and one minor stroke). By a mean follow-up of 16 months (range 2-42 months), one patient had died of refractory heart failure, while one patient had a minor ipsilateral stroke and three had minor contralateral strokes, corresponding to total MAE per patient of 4%. The rate of any stroke or death was 7%. The rate of restenosis >or=50% per lesion by ultrasound was 3.8%. CONCLUSION: This single center experience suggests that it is safe to start a CAS program following dedicated fellowship.
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The technique of transseptal puncture for catheter ablation of atrial fibrillation after percutaneous closure of a foramen ovale with the Amplatzer Occluder is demonstrated based on 2 representative cases.
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Rotational atherectomy has been regaining interest over the last couple of years after it almost has disappeared from most interventional catheterization laboratories for several years due to failure to prove its original concept of improving long term results of percutaneous coronary interventions (PCI) as was repeatedly shown in studies in the 1990s. Its revival coupled the introduction of drug-eluting stents (DES); these devices have led to treating much more complex lesions and high-risk patients by PCI. However, real-world experience suggested that off-label use of DES is associated with a higher rate of early and late stent thrombosis. Therefore, more attention is now being paid to the initial implantation technique of DES including aggressive lesion preparation to facilitate stent delivery and expansion. The limited studies with rot-ablation and DES showed promising results with no long term safety concerns. In these studies, a subtle observation was made suggesting that rot-ablation prior to DES implantation in such lesions may have an add-on effect on long term outcome compared to DES alone. An ongoing multicenter study is investigating such effect among complex calcified coronary lesions. Even if this additive benefit does not prove true, rot-ablation remains an efficient tool for preparing certain lesions to facilitate effective and safe DES implantation. Therefore, interventional training programs should focus on this difficult technique to bridge the gap of experience which resulted from neglecting it for several years. In this regard, dedicated courses at experienced sites as well as medical simulation may be appropriate.
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BACKGROUND: Patent foramen ovale (PFO) has been linked to migraine, and several retrospective studies reported an improvement in migraine prevalence or frequency after PFO closure for other reasons, mostly for secondary prevention of paradoxical embolism or following diving accidents. We investigated the outcome of patients undergoing PFO closure solely for migraine headaches refractory to medical treatment. METHODS: Seventeen patients (age 44 +/- 12 years; 76% female; one atrial septal aneurysm) underwent percutaneous PFO closure using the Amplatzer PFO Occluder (AGA Medical Corporation, Golden Valley, MN). An 18-mm device was used in two patients, a 25-mm device in 13, and a 35-mm device in two. The interventions were solely guided by fluoroscopy, without intraprocedural echocardiography. RESULTS: All implantation procedures were successful. There were no peri-procedural complications. Contrast transesophageal echocardiography after Valsalva maneuver at 6 months showed complete PFO closure in 16 patients (94%), whereas a minimal residual shunt persisted in one (6%). During 2.7 +/- 1.5 years of follow-up, no deaths and no embolic events occurred. After PFO closure, migraine headaches disappeared in four patients (24%), and improved in eight additional patients (47%). Three patients (18%) reported a decrease of their headaches by 75%, three patients (18%) a decrease of 50%, and two patients (12%) a decrease of 25%, while headaches remained unchanged in five patients (29%). No patient experienced worsening headaches. Moreover, the prevalence of migraine with aura decreased from 82 to 24% (P = 0.002). CONCLUSIONS: These results suggest that percutaneous PFO closure durably alters the spontaneous course of shunt associated migraine.