1,720,964 research outputs found
What Is New in Risk Assessment in Nuclear Cardiology?
No full text: Nuclear cardiology techniques allow in-depth evaluation of cardiac patients. A body of literature has established the use of nuclear cardiology. The results obtained with traditional cameras have been reinforced by those obtained with a series of innovations that have revolutionized the field of nuclear cardiology. This article highlights the role of nuclear cardiology in the risk assessment of patients with cardiac disease and sheds light on advancements of nuclear imaging techniques in the cardiovascular field. Patient risk stratification has a key role in modern precision medicine. Nuclear cardiac imaging techniques may quantitatively investigate major disease mechanisms of different cardiac pathologies
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
Utility of risk scores to predict adverse events in cardiac lead extraction
No full textIntroduction: Increasing device implantations, patient comorbidities, and longer life expectancy contribute to an increased need for lead extraction. Even if transvenous lead extraction (TLE) is a highly successful procedure, some serious procedural complications are reported. In order to identify those patients who are at higher risk, risk stratification scores were proposed.Areas covered: The major obstacles to lead extractions are represented by the body's response to the foreign implanted material and by the following development of fibrotic reaction between the lead and the vascular system. Several clinical factors and device features are associated with major complications and worse outcomes. Although different multiparametric scores predicting the safety and the efficacy of TLE procedures were reported, none of these scores were prospective evaluated.Expert commentary: A correct risk stratification is needed in order to refer complex patients to centers with proven experience and avoid futile procedures. Furthermore, the identification of high-risk patients allows to perform the extraction procedure in the operating room instead of electrophysiology lab. Albeit some risk scores able to predict adverse event in cardiac lead extraction were described, there are still several limitations to their use and reproducibility
Predictors of recurrence of paroxysmal atrial fibrillation after REDO ablation procedures using an automated lesion tagging system
No full textAims: To evaluate the long-term outcome of patients with paroxysmal atrial fibrillation (AF) undergoing REDO ablation procedures with an automated ablation tagging module (VISITAG), and to define the major predictors of AF recurrence.
Methods: Fifty-three patients with symptomatic paroxysmal AF undergoing REDO ablation procedures with VISITAG were enrolled. In every patient, the technique used during the first ablation procedure was evaluated, including the previous use of VISITAG. Patients were followed-up for a mean of 15±6 months and the main predictors of AF recurrence among clinical, cardiac functional, and procedural variables were individuated. To provide a comparison, a matched group of historical patients who underwent REDO AF ablation procedures without VISITAG was also selected.
Results: The average age of the population was 61±9 years, with a higher prevalence of men over women (41 vs 12 patients, respectively). The majority of the patients presented left atrial dilatation (68%) and preserved left ventricle ejection fraction (mean 60±4%) on echocardiography. In 24 (45%) patients VISITAG was already used during the first ablation procedure. After REDO ablation 35 patients (66%) were free from AF recurrence at the last available follow-up. The long-term recurrence rate of AF was numerically higher in patients ablated with VISITAG during the first procedure than in the rest of the population (50% vs 21%; P=0.024). However, on multivariate Cox regression analysis, female gender (HR: 6.17; 95% CI: 1.60-23.73; P=0.008) and left atrial dilatation (HR: 9.47; 95% CI: 1.23-72.75; P=0.031) resulted the only independent predictors of long-term AF recurrence, overwhelming the effects of major clinical and procedural data. The success rate of REDO ablation procedures of the study population was not significantly different from that of the historical cohort (P=0.932).
Conclusions: Female gender and left atrial dilatation are the most powerful predictors of AF recurrence after REDO ablation procedures. No significant impact of major procedural data was detected, with limited additional benefit coming from the use of dedicated ablation VISITAG tagging module
Patogenesi multifattoriale dell'ischemia miocardica nella cardiopatia ischemica cronica
No full textLa cardiopatia ischemica è una sindrome a patogenesi, presentazione clinica e prognosi ampiamente variabili nelle popolazioni affette. Anche considerando pazienti con quadri clinici relativamente omogenei, quali quelli affetti da angina da sforzo, la patogenesi della malattia è costantemente multifattoriale.Questo lavoro è stato progettato con lo scopo di delineare, in una popolazione omogenea di pazienti affetti da angina stabile da sforzo, i meccanismi patogenetici responsabili della sindrome ischemica. Ogni paziente della popolazione in studio sarà sottoposto in sequenza casuale al test da sforzo, al test eco-dipiridamolo, al test eco-dobutamina e successivamente, indipendentemente dal risultato dei precedenti test, alla coronarografia, con lo scopo di accertare in questa popolazione la prevalenza dell’aterosclerosi coronarica e la riproducibilità dei sintomi, delle modificazioni elettrocardiografiche e delle alterazioni della cinetica cardiaca causati dai tre test. Il ruolo predittivo delle variabili considerate sarà quindi valutato in un follow-up di breve e medio termine
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
Feasibility and long-term effectiveness of a non-apical Micra pacemaker implantation in a referral centre for lead extraction
No full textAims To demonstrate the feasibility and long-term performances of a non-apical Micra pacemaker implantation.Methods and results Fifty-two consecutive patients underwent Micra implantation, targeting a non-apical site of delivery when feasible. Each patient received a regular follow-up (mean 13 +/- 9 months). The first 17 patients were also enrolled in the Micra transcatheter pacing system trial (Group 1); the remaining ones presented broader indications and included post-extraction subjects (Group 2). In 19 of 52 patients (Group 1: 6%, Group 2: 51%; P = 0.002) Micra was implanted because of high-risk characteristics that discouraged the implantation of a traditional pacemaker. In 31 of 52 patients (60%) Micra was implanted in a non-apical location, with a lower rate of single delivery compared with apical sites (48% vs. 81%, P = 0.035), but without any impact on electrical performance. Pacing threshold remained optimal in the majority of patients (94%), regardless of the site of implantation (apical vs. non-apical location: 0.50 vs. 0.52 V/0.24 ms; P = 0.856) and group membership, with only 6% of the subjects showing elevated values (mean 1.92 +/- 0.92 V/0.24 ms) at the last follow-up. No device-related adverse events were registered.Conclusion Micra pacemaker implant is a safe and effective procedure even in a real life cohort of high-risk patients. A non- apical site of implantation is feasible in the majority of patients allowing stable electrical performance at long-term follow-up
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