1,720,959 research outputs found
Left ventricular reverse remodeling after transcatheter aortic valve implantation complicated by paroxysmal complete atrioventricular block
No full textAn 86-year-old man with unremarkable clinical history complaining of asthenia and dyspnea was diagnosed with low-flow low-gradient aortic stenosis [LFLG-AS; left ventricular ejection fraction (LVEF) 40% and transaortic mean gradient 37 mmHg, increasing to 52% and 55 mmHg after dobutamine infusion]. The patient underwent transcatheter aortic valve implantation (TAVI; Edwards CENTERATM 29, Irvine, CA, USA). The procedure and the following hospital stay were free from complications, with no changes on electrocardiography (ECG). Six months later, few syncopal episodes occurred. No signs of orthostatic hypotension or neurologic disorders were present. Echocardiography showed normal functioning of the prosthetic valve and recovery of LV systolic function (LVEF 55%). Baseline ECG and 24-h Holter monitoring were unremarkable. An implantable loop recorder (ILR) was implanted to verify the occurrence of paroxysmal conduction disturbances. One month later, during a syncopal episode, ILR interrogation showed a complete atrioventricular (AV) block. Therefore, a dual chamber, single lead pacemaker was implanted. We are providing the first report of complete AV block occurring months after TAVI, possibly because of reverse LV remodeling following TAVI, with ensuing relative oversizing of the prosthetic valve. This possibility should be considered in patients with syncope not otherwise explained, and previous TAVI, especially in cases of LFLG-AS.
La funzione renale nello scompenso cardiaco
No full textNumerose malattie sono in grado di determinare Insufficienza Cardiaca ed Insufficienza Renale e la disfunzione di uno dei due organi tende a coinvolgere l’altro. Dalla letteratura apprendiamo che gli indici di alterata funzione renale sono predittori indipendenti di morbilità e mortalità cardiovascolare in genere ed in particolare nello scompenso cardiaco cronico.Anche l’anemia, spesso associata ad insufficienza renale cronica, è fattore di rischio indipendente per mortalità nei pazienti con scompenso cardiaco.
Scopo di questa tesi è stato quello di valutare la funzione renale in un’ampia popolazione di pazienti affetti da Scompenso cardiaco e di verificarne il valore predittivo.
La casistica comprende 1260 pazienti con scompenso cardiaco, dei quali sono stati studiati i parametri clinici e strumentali per la valutazione della funzione cardiaca e della funzione renale. Come parametri di funzione cardiaca sono stati scelti la frequenza cardiaca, la pressione arteriosa media ei i principali parametri ecocardiografici . Come parametri di funzione renale sono stati utilizzati la creatininemia e il Filtrato Glomerulare (GRF) calcolato secondo varie formule: la formula di Cockroft-Gault (C-G), il C-G corretto per la superficie corporea (C-G BSA) e il Modification of Diet in Renal Disease semplificato (sMDRD).
E’ stato effettuato un confronto tra maschi e femmine e tra pazienti che nel corso del follow-up sono deceduti e pazienti in vita.
L’ampiezza del campione ha inoltre permesso un confronto delle varie formule tra loro e con i principali dati antropometrici e clinico-strumentali.
Dal confronto tra maschi e femmine è emerso che le donne hanno una età media più alta ma una migliore funzione ventricolare sistolica mentre gli uomini hanno una funzione renale significativamente peggiore ma valori di emoglobinemia maggiori.
Dal confronto tra vivi e morti è emerso che i pazienti deceduti avevano età media maggiore, appartenevano a classi NYHA più alte, con una peggiore funzione ventricolare e con una pressione arteriosa media più bassa rispetto ai vivi. Inoltre avevano un BMI ridotto. La loro funzione renale risultava peggiore rispetto ai soggetti in vita con differenze significative sia per creatiniemia che C-G , C-G BSA e sMDRD.
Tutti i parametri di funzione renale analizzati sono tra loro correlati in maniera significativa, in particolare le correlazioni C-G - sMDRD (r 0.83, p <0.0001) e C-G BSA - sMDRD ( r 0.91, p<0.0001), indipendentemente dalla stratificazione per classi di BMI
Gestione del paziente con Sindrome Coronarica Acuta: dalle linee guida alla pratica clinica
No full textLe sindromi coronariche acute (SCA) rappresentano un problema sanitario in tutto il mondo con un’incidenza di 3 persone su 1.000 abitanti all’anno. Secondo dati amministrativi, ogni anno vengono ricoverati in Italia oltre 150.000 pazienti con SCA. L’insieme dei dati dei registi ANMCO e di quelli internazionali indica un chiaro trend verso un continuo aumento dei ricoveri per Infarto Miocardico Non-ST elevato (NSTEMI) ed angina instabile (UA) rispetto a quelli per Infarto Miocardico ST Elevato (STEMI). Lo scopo di questo studio è quello di descrivere l’epidemiologia dei pazienti dimessi dal nostro centro nel corso dell’anno 2015 con diagnosi di SCA, confrontare la gestione clinica di tali pazienti rispetto a quanto indicato nelle più recenti linee guida europee e valutarne l’impatto prognostico. Sono stati studiati retrospettivamente 369 pazienti (Maschi 260 - Femmine 109). In particolare sono stati valutati i seguenti aspetti :
•tempestività della terapia riperfusiva nei pazienti con STEMI (n = 179)
•stratificazione del rischio e conseguente scelta della strategia invasiva o conservativa nei pazienti con NSTEMI (n = 163) o UA (n = 27)
•aderenza alle linee guida nella prescrizione della terapia per la prevenzione secondaria in tutta la popolazione in studio
•impatto prognostico attraverso un follow-up di 10±4 mes
Predictors of zero X ray procedures in supraventricular arrhythmias ablation
No full textTo evaluate predictors of zero-X ray procedures for supraventricular arrhythmias (SVT) using minimally fluoroscopic approach (MFA). Patients referred for RF catheter ablation of SVT were admitted for a MFA with an electro-anatomical navigation system or a conventional fluoroscopic approach (ConvA). Exclusion criterion was the need to perform a transseptal puncture. 206 patients (98 men, age 53 +/- 19 years) underwent an EP study, 93 (45%) with an MFA and 113 (55%) with a ConvA. Fifty-five had no inducible arrhythmias (EPS). Fifty-four had AV nodal reentrant tachycardia (AVNRT), 49 patients had typical atrial flutter (AFL), 37 had AV reciprocating tachycardia (AVRT/WPW), 11 had focal atrial tachycardia (AT), and underwent a RF ablation. X-ray was not used at all in 51/93 (58%) procedures (zero X ray). MFA was associated with a significant reduction in total fluoroscopy time (5.5 +/- 10 vs 13 +/- 18 min, P = 0.01) and operator radiation dose (0.8 +/- 2.5 vs 3 +/- 8.2 mSV, P < 0.05). The greatest absolute dose reduction was observed in AVNRT (0.1 +/- 0.3 vs 5.1 +/- 10 mSV, P = 0.01, 98% relative dose reduction) and in AFL (1.3 +/- 3.6 vs 11 +/- 16 mSV, P = 0.003, 88% relative dose reduction) groups. Both AVNRT or AFL resulted the only statistically significant predictors of zero x ray at multivariate analysis (OR 4.5, 95% CI 1.5-13 and OR 5, 95% CI 1.7-15, P < 0.001, respectively). Success and complication rate was comparable between groups (P = NS). Using MFA for SVT ablation, radiological exposure is significantly reduced. Type of arrhythmia is the strongest predictor of zero X ray procedure
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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