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Response to the letter 'Dual atrioventricular nodal non-reentrant tachycardia: an often overlooked diagnosis'
Interpolated junctional extrasystoles mimicking complex polymorphic ventricular arrhythmias in a healthy young athlete: a case report
Background In young competitive athletes, ventricular arrhythmias could be a reason for concern as they may represent the sign of a serious underlying cardiac condition. On the other hand, atrial or conduction system premature beats are usually benign. However, when the properties of the His-Purkinje system lead to conduction aberrancies, there is a risk of misinterpreting benign arrhythmias as potentially at risk ventricular ectopic beats.Case summary We described the case of a healthy young athlete with asymptomatic interpolated junctional ectopic beats interpreted as polymorphic ventricular tachycardia during pre-participation screening.Discussion Strange and rare electrocardiogram pictures may be observed during sport pre-participation screening. The small atrioventricular (AV) junction is made up of many specialized fibres with different conduction properties. Junctional arrhythmias can have a normal anterograde conduction or can be conducted with aberrancy. Rarely, they can be interpolated and cause PR prolongation or bundle branch block by increasing the refractory period of the AV node and/or the conduction system. When aberrancy occurs, they can be mistaken for 'atypical' ventricular arrhythmias. Prognosis of these events remains uncertain
Right Ventricular Outflow Tract Tachycardia with Structural Abnormalities of the Right Ventricle and Left Ventricular Diverticulum
A 43-year-old woman presented to the emergency room with a sustained ventricular tachycardia (VT). ECG showed a QRS in left bundle branch block morphology with inferior axis. Echocardiography, ventricular angiography, and cardiac magnetic resonance imaging (CMRI) revealed a normal right ventricle and a left ventricular diverticulum. Electrophysiology studies with epicardial voltage mapping identified a large fibrotic area in the inferolateral layer of the right ventricular wall and a small area of fibrotic tissue at the anterior right ventricular outflow tract. VT ablation was successfully performed with combined epicardial and endocardial approaches
2:1 Pulsus and electrical alternans during atrioventricular reciprocating tachycardia in a healthy young man: A case report
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
Arrhythmic Mitral Valve Prolapse in the Young: A Rare but Concerning Entity
Arrhythmic mitral valve prolapse (MVP) is an increasingly recognized clinical entity, characterized by the association of myxomatous mitral valve, ventricular arrhythmias (VAs) and sudden cardiac death (SCD). Prevalence of MVP is reported ranging between 2% and 5% of the general population, and risk of SCD is estimated approximately 0.3% per year. Diagnosis of MVP and the occurrence of fatal events involve generally adults aged 30 to 50 years, whereas in younger and even pediatric individuals has rarely been described. Herein, we report two clinical cases of malignant MVP in young patients, with the aim to point out the clinical features and the challenge of clinical management and risk stratification
Variations on the Author
“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
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