986 resultados para Postoperative Myocardial-ischemia


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BACKGROUND: Coronary artery calcification (CAC) detected by computed tomography is a noninvasive measure of coronary atherosclerosis, which underlies most cases of myocardial infarction (MI). We sought to identify common genetic variants associated with CAC and further investigate their associations with MI. METHODS AND RESULTS: Computed tomography was used to assess quantity of CAC. A meta-analysis of genome-wide association studies for CAC was performed in 9961 men and women from 5 independent community-based cohorts, with replication in 3 additional independent cohorts (n=6032). We examined the top single-nucleotide polymorphisms (SNPs) associated with CAC quantity for association with MI in multiple large genome-wide association studies of MI. Genome-wide significant associations with CAC for SNPs on chromosome 9p21 near CDKN2A and CDKN2B (top SNP: rs1333049; P=7.58×10(-19)) and 6p24 (top SNP: rs9349379, within the PHACTR1 gene; P=2.65×10(-11)) replicated for CAC and for MI. Additionally, there is evidence for concordance of SNP associations with both CAC and MI at a number of other loci, including 3q22 (MRAS gene), 13q34 (COL4A1/COL4A2 genes), and 1p13 (SORT1 gene). CONCLUSIONS: SNPs in the 9p21 and PHACTR1 gene loci were strongly associated with CAC and MI, and there are suggestive associations with both CAC and MI of SNPs in additional loci. Multiple genetic loci are associated with development of both underlying coronary atherosclerosis and clinical events.

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Background: Transcatheter aortic valve implantations (TAVI) are indicated in high risk patients requiring aortic valve replacement (AVR). However, CT-scans, coronary angiograms and intraoperative aortographies can induce contrast-related nephro-toxicity with a concrete risk of acute postoperative renal failure, especially in severely diseased patients. To prevent this complication, we routinely perform transapical (TA) TAVI guided by transesophageal echocardiogram and fluoroscopy without angiography. Material and Methods: From November 2008 to December 2009, 31 high-risk patients suffering from severe symptomatic aortic stenosis underwent TA-TAVI in our institution. The preoperative imaging assessment (cardiac CT-scan and coronary angiogram) was performed no less than 10 days before the TA-TAVI in all patients (to recover the renal function) with a low-dose protocol for injected contrast medium (equivalent to the patient's weight for the CT-scan). During the TA-TAVI, the stent-valve positioning was performed without any contrast injection. Results: 32 consecutive stent-valve were successfully positioned in 31 patients (mean age 80.76 8 8.3 years; mean EuroSCORE: 32.2 8 12.9%) through a transapical access (1 patient required 2 valves for valve embolisation). The mean preoperative creatinine and urea blood levels were 102.6 8 67.7 _ g/dl (range 53-339 _ g/dl) and 8.45 8 4.9 mmol/l, respectively. A chronic renal insufficiency affected 12 patients (38.7%) with 1 patient in pre-dialysis. Postoperatively, no patient developed acute myocardial infarction, atrio-ventricular block or acute renal insufficiency (mean creatinine level: 89.7 8 64.55 _ g/dl; urea level: 7.11 8 3.47 mmol/l) and the 30-days mortality was 9.67% (3 patients). Conclusion: Specific preoperative and intraoperative protocols that require lowdoses or absence of contrast medium are useful to preserve the renal function in high risk patients operated for TAVI.

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The treatments for ischemic stroke can only be administered in a narrow time-window. However, the ischemia onset time is unknown in ~30% of stroke patients (wake-up strokes). The objective of this study was to determine whether MR spectra of ischemic brains might allow the precise estimation of cerebral ischemia onset time. We modeled ischemic stroke in male ICR-CD1 mice using a permanent middle cerebral artery filament occlusion model with laser Doppler control of the regional cerebral blood flow. Mice were then subjected to repeated MRS measurements of ipsilateral striatum at 14.1 T. A striking initial increase in γ-aminobutyric acid (GABA) and no increase in glutamine were observed. A steady decline was observed for taurine (Tau), N-acetyl-aspartate (NAA) and similarly for the sum of NAA+Tau+glutamate that mimicked an exponential function. The estimation of the time of onset of permanent ischemia within 6 hours in a blinded experiment with mice showed an accuracy of 33±10 minutes. A plot of GABA, Tau, and neuronal marker concentrations against the ratio of acetate/NAA allowed precise separation of mice whose ischemia onset lay within arbitrarily chosen time-windows. We conclude that (1)H-MRS has the potential to detect the clinically relevant time of onset of ischemic stroke.

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Endoscopy constitutes an important investigation in the presence of a gastro-oesophageal reflux. The primary intention is to exclude the possibility of an organic pathology, for example cancer, which has not been demonstrated by other investigative procedures. Accordingly it must provide a detailed exploration of the whole superior digestive tract, from the mouth to the duodenum. Secondly, endoscopy must establish the consequence of the reflux on the mucosa of the lower oesophagus both by a macroscopic and a detailed microscopic description. Peptic lesions are classified according to 4 degrees of severity. The difficulty in evaluating the very early lesions (1st degree) and the advanced stages (4th degree) necessitates systematic biopsies of the lesions. The erythroplasic type of carcinoma in situ can present the same endoscopic changes as a 1st degree peptic lesion, whereas the exclusion of an adenocarcinoma constitutes the major preoccupation at the time of endoscopy of a 4th degree oesophagitis.

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PURPOSE: To assess the feasibility and efficacy of accelerated postoperative radiation therapy (RT) in patients with squamous-cell carcinoma of the head and neck (SCCHN). PATIENTS AND METHODS: Between December 1997 and July 2001, 68 patients (male to female ratio: 52/16; median age: 60-years (range: 43-81) with pT1-pT4 and/or pN0-pN3 SCCHN (24 oropharynx, 19 oral cavity, 13 hypopharynx, 5 larynx, 3 unknown primary, 2 maxillary sinus, and 2 salivary gland) were included in this prospective study. Postoperative RT was indicated because extracapsular infiltration (ECI) was observed in 20 (29%), positive surgical margins (PSM) in 20 (29%) or both in 23 patients (34%). Treatment consisted of external beam RT 66 Gy in 5 weeks and 3 days. Median follow-up was 15 months. RESULTS: According to CTC 2.0, acute morbidity was acceptable: grade 3 mucositis was observed in 15 (22%) patients, grade 3 dysphagia in 19 (28%) patients, grade 3 skin erythema in 21 (31%) patients with a median weight loss of 3.1 kg (range: 0-16). No grade 4 toxicity was observed. Median time to relapse was 13 months; we observed only three (4%) local and four (6%) regional relapses, whereas eight (12%) patients developed distant metastases without any evidence of locoregional recurrence. The 2 years overall-, disease-free survival, and actuarial locoregional control rates were 85, 73 and 83% respectively. CONCLUSION: The reduction of the overall treatment time using postoperative accelerated RT with weekly concomitant boost (six fractions per week) is feasible with local control rates comparable to that of published data. Acute RT-related morbidity is acceptable.

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In vivo exposure to chronic hypoxia is considered to be a cause of myocardial dysfunction, thereby representing a deleterious condition, but repeated aeration episodes may exert some cardioprotection. We investigated the possible role of ATP-sensitive potassium channels in these mechanisms. First, rats (n = 8/group) were exposed for 14 days to either chronic hypoxia (CH; 10% O(2)) or chronic hypoxia with one episode/day of 1-hr normoxic aeration (CH+A), with normoxia (N) as the control. Second, isolated hearts were Langendorff perfused under hypoxia (10% O(2), 30 min) and reoxygenated (94% O(2), 30 min) with or without 3 microM glibenclamide (nonselective K(+)(ATP) channel-blocker) or 100 microM diazoxide (selective mitochondrial K(+)(ATP) channel-opener). Blood gasses, hemoglobin concentration, and plasma malondialdehyde were similar in CH and CH+A and in both different from normoxic (P < 0.01), body weight gain and plasma nitrate/nitrite were higher in CH+A than CH (P < 0.01), whereas apoptosis (number of TUNEL-positive nuclei) was less in CH+A than CH (P < 0.05). During in vitro hypoxia, the efficiency (ratio of ATP production/pressure x rate product) was the same in all groups and diazoxide had no measurable effects on myocardial performance, whereas glibenclamide increased end-diastolic pressure more in N and CH than in CH+A hearts (P < 0.05). During reoxgenation, efficiency was markedly less in CH with respect to N and CH+A (P < 0.0001), and ratex pressure product remained lower in CH than N and CH+A hearts (P < 0.001), but glibenclamide or diazoxide abolished this difference. Glibenclamide, but not diazoxide, decreased vascular resistance in N and CH (P < 0.005 and < 0.001) without changes in CH+A. We hypothesize that cardioprotection in chronically hypoxic hearts derive from cell depolarization by sarcolemmal K(+)(ATP) blockade or from preservation of oxidative phosphorylation efficiency (ATP turnover/myocardial performance) by mitochondrial K(+)(ATP) opening. Therefore K(+)(ATP) channels are involved in the deleterious effects of chronic hypoxia and in the cardioprotection elicited when chronic hypoxia is interrupted with short normoxic aeration episodes.

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The aim of this master's thesis was to assess the ten- year trends and regional differences in management and outcome of acute myocardial infarction (AMI) within Switzerland. The thesis is composed of two articles. First, in the article "Trends in hospital management of acute myocardial infarction in Switzerland, 1998 to 2008" over 102,700 cases of AMI with corresponding management and revascularization procedures were assessed. The results showed a considerable increase in the numbers of hospital discharges for AMI, namely due to the increase of between- hospital transfers. Rates of intensive care unit admissions remained stable. All types of revascularization procedures showed an increase. In particular, overall stenting rates increased with drug-eluting stents partly replacing bare stents. Second, in the article "The region makes the difference: disparities in management of acute myocardial infarction within Switzerland" around 25,600 cases of AMI with corresponding management were assessed for the period of 2007-2008 and according to seven Swiss regions. As reported by our results, considerable regional differences in AMI management were stated within Switzerland. Although each region showed different trends regarding revascularization interventions, Leman and Ticino contrast significantly by presenting the minimum and maximum rates in almost all assessed parameters. As a consequence these two regions differ the most from the Swiss average. The impact of the changes in trends and the regional differences in AMI management on Swiss patient's outcome and economics remains to be assessed. Purpose: To assess ten-year trends in management and outcome of acute myocardial infarction (AMI) in Switzerland. Methods: Swiss hospital discharge database for the 1998 to 2008 period. AMI was defined as a primary discharge diagnosis code I21 according to the CIM-10 classification of the World Health Organization. Management and revascularization procedures were assessed. Results: Overall, 102,729 hospital discharges with a diagnosis of AMI were analyzed. The number of hospital discharges increased almost three-fold from 5530 in 1998 to 13,834 in 2008, namely due to a considerable increase in between-hospital transfers (1352 in 1998, 6494 in 2008). Relative to all hospital discharges, Intensive Care Unit admission rate was 38.0% in 1998 and remained stable (36.2%) in 2008 (p for trend=0.25). Percutaneous revascularization rates increased from 6.0% to 39.9% (p for trend<0.001). Non-drug-eluting stent use increased from 1.3% to 16.6% (p for trend<0.05). Drug eluting stents appeared in 2004 and increased to 23.5% of hospital discharges in 2008 (p for trend=0.07). Coronary artery bypass graft increased from 1.0% to 3.0% (p for trend<0.001). Circulatory assistance increased from 0.2% to 1.7% (p for trend<0.001). Thrombolysis showed no significant changes, from 0.5% to 1.9% (p for trend=0.64). Most of these trends were confirmed after multivariate adjustment. Conclusion: Between 1998 and 2008 the number of hospital discharges for AMI increased considerably in Switzerland, namely due to between-hospital transfers. Overall stenting rates increased, drug-eluting stents partly replacing bare stents. The impact of these changes on outcome and economics remains to be assessed.

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OBJECTIVES: This study sought to investigate whether self-expanding stents are more effective than balloon-expandable stents for reducing stent malapposition at 3 days after implantation in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention. BACKGROUND: Acute myocardial infarction is associated with vasoconstriction and large thrombus burden. Resolution of vasoconstriction and thrombus load during the first hours to days after primary percutaneous coronary intervention may lead to stent undersizing and malapposition, which may subsequently lead to stent thrombosis or restenosis. In addition, aggressive stent deployment may cause distal embolization. METHODS: Eighty patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention were randomized to receive a self-expanding stent (STENTYS, STENTYS SA, Paris, France) (n = 43) or a balloon-expandable stent (VISION, Abbott Vascular, Santa Clara, California; or Driver, Medtronic, Minneapolis, Minnesota) (n = 37) at 9 European centers. The primary endpoint was the proportion of stent strut malapposition at 3 days after implantation measured by optical coherence tomography. Secondary endpoints included major adverse cardiac events (cardiac death, recurrent myocardial infarction, emergent bypass surgery, or clinically driven target lesion revascularization). RESULTS: At 3 days after implantation, on a per-strut basis, a lower rate of malapposed stent struts was observed by optical coherence tomography in the self-expanding stent group than in the balloon-expandable group (0.58% vs. 5.46%, p < 0.001). On a per-patient basis, none of the patients in the self-expanding stent group versus 28% in the balloon-expandable group presented ≥5% malapposed struts (p < 0.001). At 6 months, major adverse cardiac events were 2.3% versus 0% in the self-expanding and balloon-expandable groups, respectively (p = NS). CONCLUSIONS: Strut malapposition at 3 days is significantly lower in ST-segment elevation myocardial infarction patients allocated to self-expanding stents when than in those allocated to balloon-expandable stents. The impact of this difference on clinical outcome and the risk of late stent thrombosis need to be evaluated further. (Randomized Comparison Between the STENTYS Self-expanding Coronary Stent and a Balloon-expandable Stent in Acute Myocardial Infarction [APPOSITION II]; NCT01008085).

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Three-dimensional imaging for the quantification of myocardial motion is a key step in the evaluation of cardiac disease. A tagged magnetic resonance imaging method that automatically tracks myocardial displacement in three dimensions is presented. Unlike other techniques, this method tracks both in-plane and through-plane motion from a single image plane without affecting the duration of image acquisition. A small z-encoding gradient is subsequently added to the refocusing lobe of the slice-selection gradient pulse in a slice following CSPAMM acquisition. An opposite polarity z-encoding gradient is added to the orthogonal tag direction. The additional z-gradients encode the instantaneous through plane position of the slice. The vertical and horizontal tags are used to resolve in-plane motion, while the added z-gradients is used to resolve through-plane motion. Postprocessing automatically decodes the acquired data and tracks the three-dimensional displacement of every material point within the image plane for each cine frame. Experiments include both a phantom and in vivo human validation. These studies demonstrate that the simultaneous extraction of both in-plane and through-plane displacements and pathlines from tagged images is achievable. This capability should open up new avenues for the automatic quantification of cardiac motion and strain for scientific and clinical purposes.

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Postoperative delirium after cardiac surgery is associated with increased morbidity and mortality as well as prolonged stay in both the intensive care unit and the hospital. The authors sought to identify modifiable risk factors associated with the development of postoperative delirium in elderly patients after elective cardiac surgery in order to be able to design follow-up studies aimed at the prevention of delirium by optimizing perioperative management. A post hoc analysis of data from patients enrolled in a randomized controlled trial was performed. A single university hospital. One hundred thirteen patients aged 65 or older undergoing elective cardiac surgery with cardiopulmonary bypass. None. MEASUREMENTS AND MAINS RESULTS: Screening for delirium was performed using the Confusion Assessment Method (CAM) on the first 6 postoperative days. A multivariable logistic regression model was developed to identify significant risk factors and to control for confounders. Delirium developed in 35 of 113 patients (30%). The multivariable model showed the maximum value of C-reactive protein measured postoperatively, the dose of fentanyl per kilogram of body weight administered intraoperatively, and the duration of mechanical ventilation to be independently associated with delirium. In this post hoc analysis, larger doses of fentanyl administered intraoperatively and longer duration of mechanical ventilation were associated with postoperative delirium in the elderly after cardiac surgery. Prospective randomized trials should be performed to test the hypotheses that a reduced dose of fentanyl administered intraoperatively, the use of a different opioid, or weaning protocols aimed at early extubation prevent delirium in these patients.

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Kawasaki disease is an acute vasculitis of childhood. Its clinical presentation is well known, and coronary artery aneurysms are classical complications. Shock and pleural or pericardiac effusion are rare presentations of the disease. In intensive care units, the disease may be mistaken for septic shock or toxic shock syndrome. Owing to the fact that immunoglobulin therapy improves the course of the disease, especially if given early, and thus the diagnosis should not be delayed.

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No-reflow phenomenon is a consequence of percutaneous coronary intervention (PCI) which arises most of the time in the setting of myocardial infarction, but can be also the consequence of PCI in stable angina patients (rotatablator ablation technique or angioplasty in saphenous vein grafts). In this review, we summarize two ways of treating the no-reflow according to the current literature. First through the pharmacological approach where several compounds have been assessed like adenosine, nitroprusside, verapamil, nicorandil, dipyridamole, epinephrine or cyclosporine. Second through the mechanical approach where few strategies have been examined like intra-aortic balloon pumping or postconditioning. Finally, we provide an algorithm for treating a no-reflow even though no studies showed a beneficial effect in terms of clinical endpoints.