21 research outputs found

    In Situ Spectrophotometric Measurement of Dissolved Inorganic Carbon in Seawater

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    Autonomous in situ sensors are needed to document the effects of today’s rapid ocean uptake of atmospheric carbon dioxide (e.g., ocean acidification). General environmental conditions (e.g., biofouling, turbidity) and carbon-specific conditions (e.g., wide diel variations) present significant challenges to acquiring long-term measurements of dissolved inorganic carbon (DIC) with satisfactory accuracy and resolution. SEAS-DIC is a new in situ instrument designed to provide calibrated, high-frequency, long-term measurements of DIC in marine and fresh waters. Sample water is first acidified to convert all DIC to carbon dioxide (CO2). The sample and a known reagent solution are then equilibrated across a gas-permeable membrane. Spectrophotometric measurement of reagent pH can thereby determine the sample DIC over a wide dynamic range, with inherent calibration provided by the pH indicator’s molecular characteristics. Field trials indicate that SEAS-DIC performs well in biofouling and turbid waters, with a DIC accuracy and precision of ∼2 μmol kg–1 and a measurement rate of approximately once per minute. The acidic reagent protects the sensor cell from biofouling, and the gas-permeable membrane excludes particulates from the optical path. This instrument, the first spectrophotometric system capable of automated in situ DIC measurements, positions DIC to become a key parameter for in situ CO2-system characterizations

    PREAMI: Perindopril and remodelling in elderly with acute myocardial infarction: Study rationale and design

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    PREAMI: Perindopril and remodelling in elderly with acute myocardial infarction: Study rationale and design

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    Angiotensin-converting enzyme (ACE) inhibitors reduce mortality, the development of remodeling, left ventricular (LV) dysfunction, and ischemic events, both when administered alone as long-term treatment in patients with impaired LV function and/or heart failure (HF) and as short-term treatment, early after acute myocardial infarction (AMI) and/or HF. The few data available on the use of ACE inhibitors in the elderly after AMI are conflicting. Nothing is known about the effects of ACE inhibitors in elderly postinfarction patients with preserved LV function: these patients have a remarkable medium- to long-term mortality and HF incidence after infarction. The aim of this study is to evaluate, in patients with AMI aged ≥65 years, the effects of Perindopril on the combined outcome of death, hospitalization for HF, and heart remodeling, considered to be a ≥8% increase in LV end-diastolic volume (LVEDV). Secondary objectives include the same factors listed in the primary end points hut considered separately. In addition, safety of the drug, ventricular remodeling, and adaptation are being evaluated. A total of 1100 patients with AMI (first episode or reinfarction), aged ≥65 years, and preserved or only moderately depressed LV (LV ejection fraction ≥40%), are to he enrolled and randomly assigned to treatment (8 mg for 12 months of Perindopril or placebo, in double-blind conditions). Clinical assessment is performed at fixed times, and periodic evaluations of (1) ventricular shape, dimensions, and function by quantitative 2-D echocardiography, and (2) heart rate variability and arrhythmias by ambulatory electrocardiographic monitoring are anticipated. The results and conclusions will be available by 2002 year

    Long-term reduction of atrial tachyarrhythmia recurrences in patients paced for bradycardia-tachycardia syndrome

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    Background: Atrial tachyarrhythmias (AT) are considered progressive diseases. Several rhythm control therapies for treatment of AT have been proposed. Objectives: The Italian AT500 Registry was designed to prospectively study long-term AT evolution in patients paced for the brady-tachy form of sinus node disease (BT-SND). Methods: Three hundred forty-six BT-SND patients received an antitachycardia dual-chamber pace-maker and were followed-up for a minimum of 12 months (median 19 months). Prevention and antitachycardia pacing (ATP) features were enabled in all patients. Results: During the observation period, 224 (65%) patients were treated by antiarrhythmic drugs and 45 (13%) patients were cardioverted. Five patients suffered a stroke, 4 transient ischemic attack, 22 permanent AT, and 98 AT recurrences longer than 7 days. AT mean cycle length changed from 246 to 2 70 ms, and the percentage of patients with AT-related hospitalizations significantly decreased with an annual 28% relative reduction. AT burden and the percentage of patients with AT recurrences longer than 2 days remained constant with time in the overall population but decreased significantly in the subgroup of patients who did not develop permanent AT. High ATP efficacy was associated with an increasingly higher prevention of AT recurrences longer than 2 days. Conclusion: In a long-term observation of BT-SND patients, AT-related hospitalizations decreased significantly and mean AT cycle length increased significantly. The data suggest that rhythm control therapies induce inversion of AT progression. © 2005 Heart Rhythm Society. All rights reserved

    Antithrombotic strategies in the catheterization laboratory for patients with acute coronary syndromes undergoing percutaneous coronary interventions: Insights from the EmploYEd antithrombotic therapies in patients with acute coronary Syndromes HOspitalized in Italian cardiac care units Registry

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    Aims: In the last decades, several new therapies have emerged for the treatment of acute coronary syndromes (ACS). We sought to describe real-world patterns of use of antithrombotic treatments in the catheterization laboratory for ACS patients undergoing percutaneous coronary interventions (PCI). Methods: EmploYEd antithrombotic therapies in patients with acute coronary Syndromes HOspitalized in Italian cardiac care units was a nationwide, prospective registry aimed to evaluate antithrombotic strategies employed in ACS patients in Italy. Results: Over a 3-week period, a total of 2585 consecutive ACS patients have been enrolled in 203 cardiac care units across Italy. Among these patients, 1755 underwent PCI (923 with ST-elevation myocardial infarction and 832 with non-ST-elevation ACS). In the catheterization laboratory, unfractioned heparin was the most used antithrombotic drug in both ST-elevation myocardial infarction (64.7%) and non-ST-elevation ACS (77.5%) undergoing PCI and, as aspirin, bivalirudin and glycoprotein IIb/IIIa inhibitors (GPIs) more frequently employed before or during PCI compared with the postprocedural period. Any crossover of heparin therapy occurred in 36.0% of cases, whereas switching from one P2Y12 inhibitor to another occurred in 3.7% of patients. Multivariable analysis yielded several independent predictors of GPIs and of bivalirudin use in the catheterization laboratory, mainly related to clinical presentation, PCI complexity and presence of complications during the procedure. Conclusion: In our contemporary, nationwide, all-comers cohort of ACS patients undergoing PCI, antithrombotic therapies were commonly initiated before the catheterization laboratory. In the periprocedural period, the most frequently employed drugs were unfractioned heparin, leading to a high rate of crossover, followed by GPIs and bivalirudin, mainly used during complex PCI

    Contemporary antithrombotic strategies in patients with acute coronary syndromes managed without revascularization: Insights fromthe EYESHOT study

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    Aims Patients with acute coronary syndromes (ACSs) whoare managed without coronary revascularization represent a mixed and understudied population that seems to receive suboptimal pharmacological treatment. Methods and results We assessed patterns of antithrombotic therapies employed during the hospitalization and in-hospital clinical events of medically managed patients withACS enrolled in the prospective, multicentre, nationwideEYESHOT(EmploYEd antithrombotic therapies in patients with acute coronary Syndromes HOspitalized in Italian cardiac care units) registry.Among the 2585 consecutive ACS patients enrolled in EYESHOT, 783 (30.3%) did not receive any revascularization during hospital admission. Of these, 478 (61.0%) underwent coronary angiography (CA), whereas 305 (39.0%) did not. The median GRACE and CRUSADE risk scores were significantly higher among patients who did not undergo CA compared with those who did (180 vs. 145, P, 0.0001 and 50 vs. 33, P, 0.0001, respectively). Antithrombotic therapies employed during hospitalization significantly differ between patients who received CA and those who did not with unfractioned heparin and novel P2Y12 inhibitors more frequently used in the first group, and low-molecular-weight heparins and clopidogrel in the latter group. During the index hospitalization, patients who did not receive CA presented a higher incidence of ischaemic cerebrovascular events and of mortality compared with those who underwent CA (1.6 vs. 0.2%, P = 0.04 and 7.9 vs. 2.7%, P = 0.0009, respectively). Conclusion Almost one-third of ACS patients are managed without revascularization during the index hospitalization. In this population, a lower use of recommended antiplatelet therapy and worse clinical outcome were observed in those who did not undergo CA when compared with those who did
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