963 resultados para Tricuspid Valve


Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: This study determines the prevalence of Congenital Heart Defects (CHD), diagnosed prenatally or in infancy, and fetal and perinatal mortality associated with CHD in Europe. METHODS AND RESULTS: Data were extracted from the European Surveillance of Congenital Anomalies central database for 29 population-based congenital anomaly registries in 16 European countries covering 3.3 million births during the period 2000 to 2005. CHD cases (n=26 598) comprised live births, fetal deaths from 20 weeks gestation, and terminations of pregnancy for fetal anomaly (TOPFA). The average total prevalence of CHD was 8.0 per 1000 births, and live birth prevalence was 7.2 per 1000 births, varying between countries. The total prevalence of nonchromosomal CHD was 7.0 per 1000 births, of which 3.6% were perinatal deaths, 20% prenatally diagnosed, and 5.6% TOPFA. Severe nonchromosomal CHD (ie, excluding ventricular septal defects, atrial septal defects, and pulmonary valve stenosis) occurred in 2.0 per 1000 births, of which 8.1% were perinatal deaths, 40% were prenatally diagnosed, and 14% were TOPFA (TOPFA range between countries 0% to 32%). Live-born CHD associated with Down syndrome occurred in 0.5 per 1000 births, with > 4-fold variation between countries. CONCLUSION: Annually in the European Union, we estimate 36 000 children are live born with CHD and 3000 who are diagnosed with CHD die as a TOFPA, late fetal death, or early neonatal death. Investing in primary prevention and pathogenetic research is essential to reduce this burden, as well as continuing to improve cardiac services from in utero to adulthood.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The stable isotope composition of ostracod fossils is useful for palaeoenvironmental reconstruction. Laboratory as well as 'natural environment' cultures demonstrate that the carbon and oxygen isotope compositions of ostracod shells faithfully record the environmental conditions at the time of valve precipitation. Oxygen isotope composition of ostracod calcite reflects the composition and temperature of the host water, but ostracod shells are enriched in 18O compared to the value expected for inorganic calcite precipitating under equilibrium under the same conditions. This 'vital effect' is generally constant for closely related species and equals 1.5 to 3 0/00 for Candoninae, 0 to 2.5 0/00 for Cyprididae and 0.8 to 1.5 0/00 for Cytheroidea. The carbon isotope composition of ostracod calcite is controlled by a complex interaction between the ecology of the species and environmental parameters. Previous natural environmental studies suggest that many (but not all) taxa crystallize their shells in or very close to equilibrium with the carbon isotope composition of dissolved inorganic carbon, and that the composition of littoral, epifaunal species reflects seasonal variation in the carbon isotope composition of dissolved inorganic carbon of bottom water according to their life cycles, while that of deep-water, infaunal species reflects the variation interstitial pore water according to microhabitat preferences.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Infective endocarditis (IE) mostly occurs after spontaneous low-grade bacteremia. Thus, IE cannot be prevented by circumstantial antibiotic prophylaxis. Platelet activation following bacterial-fibrinogen interaction or thrombin-mediated fibrinogen-fibrin polymerization is a critical step in vegetation formation. We tested the efficacy of antiplatelet and antithrombin to prevent experimental IE. METHODS: A rat model of experimental IE following prolonged low-grade bacteremia mimicking smoldering bacteremia in humans was used. Prophylaxis with antiplatelets (aspirin, ticlopidine [alone or in combination], eptifibatide, or abciximab) or anticoagulants (antithrombin dabigatran etexilate or anti-vitamin K acenocoumarol) was started 2 days before inoculation with Streptococcus gordonii or Staphylococcus aureus. Valve infection was assessed 24 hours later. RESULTS: Aspirin plus ticlopidine, as well as abciximab, protected 45%-88% of animals against S. gordonii and S. aureus IE (P < .05). Dabigatran etexilate protected 75% of rats against IE due to S. aureus (P < .005) but failed to protect against S. gordonii (<30% protection). Acenocoumarol was ineffective. CONCLUSIONS: Antiplatelet and direct antithrombin agents may be useful in the prophylaxis of IE in humans. In particular, the potential dual benefit of dabigatran etexilate might be reconsidered for patients with prosthetic valves, who require life-long anticoagulation and in whom S. aureus IE is associated with high mortality.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

OBJECTIVES: Laboratory detection of vancomycin-intermediate Staphylococcus aureus (VISA) and their heterogeneous VISA (hVISA) precursors is difficult. Thus, it is possible that vancomycin failures against supposedly vancomycin-susceptible S. aureus are due to undiagnosed VISA or hVISA. We tested this hypothesis in experimental endocarditis.¦METHODS: Rats with aortic valve infection due to the vancomycin-susceptible (MIC 2 mg/L), methicillin-resistant S. aureus M1V2 were treated for 2 days with doses of vancomycin that mimicked the pharmacokinetics seen in humans following intravenous administration of 1 g of the drug every 12 h. Half of the treated animals were killed 8 h after treatment arrest and half 3 days thereafter. Population analyses were done directly on vegetation homogenates or after one subculture in drug-free medium to mimic standard diagnostic procedures.¦RESULTS: Vancomycin cured 14 of 26 animals (54%; P<0.05 versus controls) after 2 days of treatment. When vegetation homogenates were plated directly on vancomycin-containing plates, 6 of 13 rats killed 8 h after treatment arrest had positive cultures, 1 of which harboured hVISA. Likewise, 6 of 13 rats killed 3 days thereafter had positive valve cultures, 5 of which harboured hVISA. However, one subculture of vegetations in drug-free broth was enough to revert all the hVISA phenotypes to the susceptible pattern of the parent. Thus, vancomycin selected for hVISA during therapy of experimental endocarditis due to vancomycin-susceptible S. aureus. These hVISA were associated with vancomycin failure. The hVISA phenotype persisted in vivo, even after vancomycin arrest, but was missed in vitro after a single passage of the vegetation homogenate on drug-free medium.¦CONCLUSIONS: hVISA might escape detection in clinical samples if they are subcultured before susceptibility tests.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Because of its severity, it is agreed that infectious endocarditis should be prevented whenever possible. Determining adequate prophylactic measures involves establishing (a) the patients at risk, (b) the procedures that might provoke bacteraemia, (c) the most effective prophylactic regimen, and (d) a balance between the risks of side effects from prophylaxis and of developing infectious endocarditis. Patients at risk and procedures inducing bacteraemia have been identified by clinical studies. On the other hand, the efficacy of prophylactic antibiotics has been based on animal studies. Randomised, placebo-controlled studies do not exist in humans because they would require large patient numbers and would raise ethical issues due to the severity of the disease. Case-control studies have indicated that infectious endocarditis prophylaxis is effective, but prevents only a limited number of cases. Animal experiments have revealed several key issues for human application. First, antibiotics do not prevent the early stages of valve colonisation, but rather kill the microorganisms after their attachment to the cardiac lesions. Second, the duration of antibiotic presence in the serum is critical. Under experimental conditions, the drugs must remain above their minimal inhibitory concentration for the organisms for > or = 10 h, to allow time for bacterial clearance from the valves. Third, antibiotic-induced killing is not the only mechanism allowing bacterial clearance. Other factors, such as platelet microbicidal proteins, may act in concert with the drugs to sterilise the lesions. Recommendations for prophylaxis have recently been revised in Europe and the USA. New information has improved the definition of groups at risk. Since most cases of infectious endocarditis are not preceded by medical procedures, primary prevention of infectious endocarditis should target infected foci responsible for spontaneous bacteraemia (e.g. poor dental hygiene). The purpose of this article is to update the existing recommendations in Switzerland, under the perspective of changing epidemiology, the availability of new drugs, and harmonisation with recommendations in other countries.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We report a patient with Marfan's syndrome and pectus excavatum who underwent open heart surgery with simultaneous correction of the sternal malformation. Permanent internal stabilization, achieved by bilateral overlapping of the bevelled ends of the lowest ribs and reinforced with sternal closure wires offered a maintained postoperative chest wall stability, avoided the potential postoperative complications of cardiac compression, and improved the aesthetic appearance of the anterior chest wall. The increased risk of bleeding due to extensive dissection was minimized by postponing the repair of pectus excavatum to when protamin is administered after termination of cardiopulmonary bypass.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This study analyzed the development of bacterial endocarditis following dental extraction in rats with periodontal disease. Periodontal disease was produced in rats by tying silk ligatures around the two maxillary first molars, and placing the animals on a high sucrose diet. Sterile aortic valve vegetations were produced by means of a transaortic catheter, and 24 hours later the maxillary first molars were extracted. The animals were killed 72 hours after the extractions. In rats with periodontal disease induced for 10 and 14 weeks, extractions resulted in an incidence of bacterial endocarditis of 24% and 50%, respectively, most of which were due to streptococcal species (two were caused by Staphylococcus [corrected] aureus). The difference, though not statistically significant (p = 0.10, chi 2 with Yates correction), shows a trend toward increased incidence of endocarditis with increasing severity of periodontal disease. This model demonstrates that one can reliably induce bacterial endocarditis after dental extractions in rats with periodontal disease.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

OBJECTIVES: The aim of this study was to evaluate the risk factors associated with Contegra graft (Medtronic Minneapolis, MN, USA) infection after reconstruction of the right ventricular outflow tract. METHODS: One hundred and six Contegra grafts were implanted between April 1999 and April 2010 for the Ross procedure (n = 46), isolated pulmonary valve replacement (n = 32), tetralogy of Fallot (n = 24), double-outlet right ventricle (n = 7), troncus arteriosus (n = 4), switch operation (n = 1) and redo of pulmonary valve replacement (n = 2). The median age of the patients was 13 years (range 0-54 years). A follow-up was completed in all cases with a median duration of 7.6 years (range 1.7-12.7 years). RESULTS: There were 3 cases of in-hospital mortality. The survival rate during 7 years was 95.7%. Despite the lifelong endocarditis prophylaxis, Contegra graft infection was diagnosed in 12 (11.3%) patients at a median time of 4.4 years (ranging from 0.4 to 8.7 years). Univariate analysis of preoperative, perioperative and postoperative variables was performed and the following risk factors for time to infection were identified: female gender with a hazard ratio (HR) of 0.19 (P = 0.042), systemic-to-pulmonary shunt (HR 6.46, P < 0.01), hypothermia (HR 0.79, P = 0.014), postoperative renal insufficiency (HR 11.97, P = 0.015) and implantation of permanent pacemaker during hospitalization (HR 5.29, P = 0.075). In 2 cases, conservative therapy was successful and, in 10 patients, replacement of the infected valve was performed. The Contegra graft was replaced by a homograft in 2 cases and by a new Contegra graft in 8 cases. Cox's proportional hazard model indicated that time to graft infection was significantly associated with tetralogy of Fallot (HR 0.06, P = 0.01), systemic-to-pulmonary shunt (HR 64.71, P < 0.01) and hypothermia (HR 0.77, P < 0.01). CONCLUSION: Contegra graft infection affected 11.3% of cases in our cohort, and thus may be considered as a frequent entity that can be predicted by both intraoperative and early postoperative factors. After the diagnosis of infection associated with the Contegra graft was confirmed, surgical treatment was the therapy of choice.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Genotypic and phenotypic tolerance was studied in penicillin treatment of experimental endocarditis due to nontolerant and tolerant Streptococcus gordonii and to their backcross transformants. The organisms were matched for in vitro and in vivo growth rates. Rats with aortic endocarditis were treated for 3 or 5 days, starting 12, 24, or 48 h after inoculation. When started at 12 h, during fast intravegetation growth, 3 days of treatment cured 80% of the nontolerant parent compared with &lt;30% of the tolerant derivative (P &lt; .005). When started at 24 or 48 h and if intravegetation growth had reached a plateau, 3 days of treatment failed against both bacteria. However, a significant difference between the 2 organisms was restored when treatment was extended to 5 days. Thus, genotypic tolerance conferred a survival advantage in both fast- and slow-growing bacteria, demonstrating that the in vitro-defined tolerant phenotype also carried the risk of treatment failure in vivo.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In the developing heart, Notch signaling plays an essential role in several key developmental processes, such as epithelial-to-mesenchymal transition and myocyte proliferation and differentiation. The importance of Notch in cardiac development has been demonstrated in knockout mice carrying null mutations in genes encoding components of the Notch pathway. Furthermore, humans with inactivating mutations in the Notch ligand Jagged1 suffer from Alagille syndrome, a condition characterized by several cardiac defects. Notch1 receptor haploinsufficiency has also been involved in aortic valve disease in humans. In addition, accumulating evidence indicates that Notch may also regulate homeostasis in the adult heart. Notch may protect the heart from an excessive and detrimental hypertrophic response and increase cardiomyocyte survival. Emerging evidence also suggests that Notch could be important for cardiac tissue renewal by controlling the maintenance and commitment of a cardiac stem cell compartment.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Primitive lymphatic vessels are remodeled into functionally specialized initial and collecting lymphatics during development. Lymphatic endothelial cell (LEC) junctions in initial lymphatics transform from a zipper-like to a button-like pattern during collecting vessel development, but what regulates this process is largely unknown. Angiopoietin 2 (Ang2) deficiency leads to abnormal lymphatic vessels. Here we found that an ANG2-blocking antibody inhibited embryonic lymphangiogenesis, whereas endothelium-specific ANG2 overexpression induced lymphatic hyperplasia. ANG2 inhibition blocked VE-cadherin phosphorylation at tyrosine residue 685 and the concomitant formation of button-like junctions in initial lymphatics. The defective junctions were associated with impaired lymph uptake. In collecting lymphatics, adherens junctions were disrupted, and the vessels leaked upon ANG2 blockade or gene deletion. ANG2 inhibition also suppressed the onset of lymphatic valve formation and subsequent valve maturation. These data identify ANG2 as the first essential regulator of the functionally important interendothelial cell-cell junctions that form during lymphatic development.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background/Purpose: The primary treatment goals for gouty arthritis (GA) are rapid relief of pain and inflammation during acute attacks, and long-term hyperuricemia management. A post-hoc analysis of 2 pivotal trials was performed to assess efficacy and safety of canakinumab (CAN), a fully human monoclonal anti-IL-1_ antibody, vs triamcinolone acetonide (TA) in GA patients unable to use NSAIDs and colchicine, and who were on stable urate lowering therapy (ULT) or unable to use ULT. Methods: In these 12-week, randomized, multicenter, double-blind, double-dummy, active-controlled studies (_-RELIEVED and _-RELIEVED II), patients had to have frequent attacks (_3 attacks in previous year) meeting preliminary GA ACR 1977 criteria, and were unresponsive, intolerant, or contraindicated to NSAIDs and/or colchicine, and if on ULT, ULT was stable. Patients were randomized during an acute attack to single dose CAN 150 mg s.c. or TA 40 mg i.m. and were redosed "on demand" for each new attack. Patients completing the core studies were enrolled into blinded 12-week extension studies to further investigate on-demand use of CAN vs TA for new attacks. The subpopulation selected for this post-hoc analysis was (a) unable to use NSAIDs and colchicine due to contraindication, intolerance or lack of efficacy for these drugs, and (b) currently on ULT, or contraindication or previous failure of ULT, as determined by investigators. Subpopulation comprised 101 patients (51 CAN; 50 TA) out of 454 total. Results: Several co-morbidities, including hypertension (56%), obesity (56%), diabetes (18%), and ischemic heart disease (13%) were reported in 90% of this subpopulation. Pain intensity (VAS 100 mm scale) was comparable between CAN and TA treatment groups at baseline (least-square [LS] mean 74.6 and 74.4 mm, respectively). A significantly lower pain score was reported with CAN vs TA at 72 hours post dose (1st co-primary endpoint on baseline flare; LS mean, 23.5 vs 33.6 mm; difference _10.2 mm; 95% CI, _19.9, _0.4; P_0.0208 [1-sided]). CAN significantly reduced risk for their first new attacks by 61% vs TA (HR 0.39; 95% CI, 0.17-0.91, P_0.0151 [1-sided]) for the first 12 weeks (2nd co-primary endpoint), and by 61% vs TA (HR 0.39; 95% CI, 0.19-0.79, P_0.0047 [1-sided]) over 24 weeks. Serum urate levels increased for CAN vs TA with mean change from baseline reaching a maximum of _0.7 _ 2.0 vs _0.1 _ 1.8 mg/dL at 8 weeks, and _0.3 _ 2.0 vs _0.2 _ 1.4 mg/dL at end of study (all had GA attack at baseline). Adverse Events (AEs) were reported in 33 (66%) CAN and 24 (47.1%) TA patients. Infections and infestations were the most common AEs, reported in 10 (20%) and 5 (10%) patients treated with CAN and TA respectively. Incidence of SAEs was comparable between CAN (gastritis, gastroenteritis, chronic renal failure) and TA (aortic valve incompetence, cardiomyopathy, aortic stenosis, diarrohea, nausea, vomiting, bicuspid aortic valve) groups (2 [4.0%] vs 2 [3.9%]). Conclusion: CAN provided superior pain relief and reduced risk of new attack in highly-comorbid GA patients unable to use NSAIDs and colchicine, and who were currently on stable ULT or unable to use ULT. The safety profile in this post-hoc subpopulation was consistent with the overall _-RELIEVED and _-RELIEVED II population.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Context Heart failure (HF) is the most common complication of infective endocarditis. However, clinical characteristics of HF in patients with infective endocarditis, use of surgical therapy, and their associations with patient outcome are not well described.Objectives To determine the clinical, echocardiographic, and microbiological variables associated with HF in patients with definite infective endocarditis and to examine variables independently associated with in-hospital and 1-year mortality for patients with infective endocarditis and HF, including the use and association of surgery with outcome.Design, Setting, and Patients The International Collaboration on Endocarditis-Prospective Cohort Study, a prospective, multicenter study enrolling 4166 patients with definite native- or prosthetic-valve infective endocarditis from 61 centers in 28 countries between June 2000 and December 2006.Main Outcome Measures In-hospital and 1-year mortality.Results Of 4075 patients with infective endocarditis and known HF status enrolled, 1359 (33.4% [95% CI, 31.9%-34.8%]) had HF, and 906 (66.7% [95% CI, 64.2%-69.2%]) were classified as having New York Heart Association class III or IV symptom status. Within the subset with HF, 839 (61.7% [95% CI, 59.2%-64.3%]) underwent valvular surgery during the index hospitalization. In-hospital mortality was 29.7% (95% CI, 27.2%-32.1%) for the entire HF cohort, with lower mortality observed in patients undergoing valvular surgery compared with medical therapy alone (20.6% [95% CI, 17.9%-23.4%] vs 44.8% [95% CI, 40.4%-49.0%], respectively; P < .001). One-year mortality was 29.1% (95% CI, 26.0%-32.2%) in patients undergoing valvular surgery vs 58.4% (95% CI, 54.1%-62.6%) in those not undergoing surgery (P < .001). Cox proportional hazards modeling with propensity score adjustment for surgery showed that advanced age, diabetes mellitus, health care-associated infection, causative microorganism (Staphylococcus aureus or fungi), severe HF (New York Heart Association class III or IV), stroke, and paravalvular complications were independently associated with 1-year mortality, whereas valvular surgery during the initial hospitalization was associated with lower mortality.Conclusion In this cohort of patients with infective endocarditis complicated by HF, severity of HF was strongly associated with surgical therapy and subsequent mortality, whereas valvular surgery was associated with lower in-hospital and 1-year mortality.