Arrhythmia detection using an implantable loop recorder after a negative electrophysiology study in Brugada syndrome: Observations from a multicenter international registry.

BACKGROUND: Risk stratification in Brugada syndrome (BrS) remains controversial. In this respect, the role of the electrophysiology study (EPS) has been a subject of debate. In some centers, it is common practice to use an implantable loop recorder (ILR) after a negative EPS to help in risk stratification. However, the diagnostic value of this approach has never been specifically addressed. OBJECTIVE: The aim of this study was to describe the baseline characteristics and the main findings of a diagnostic workup strategy with an ILR after a negative EPS in BrS. METHODS: We conducted a retrospective international registry including patients with BrS and negative EPS (ie, noninducible ventricular tachycardia or ventricular fibrillation) before ILR monitoring. RESULTS: The study included 65 patients from 8 referral hospitals in The Netherlands, Spain, and the United Kingdom (mean age, 39 ± 16 years; 72% male). The main indication for ILR monitoring was unexplained syncope/presyncope (66.2%). During a median follow-up of 39.0 months (Q1 25.0-Q3 47.6 months), 18 patients (27.7%) experienced 21 arrhythmic events (AEs). None of the patients died during follow-up. Bradyarrhythmias were the most common finding (47.6%), followed by atrial tachyarrhythmias (38.1%). Only 3 patients presented with ventricular arrhythmias. AEs were considered incidental in 12 patients (66.7%). In 11 patients (61.1%), AEs led to specific changes in treatment. CONCLUSION: The use of ILR after a negative EPS in BrS is a safe strategy that reflected the high negative predictive value of EPS for ventricular arrhythmia in this syndrome. In addition, it allowed the detection of AEs in a significant proportion of patients, with therapeutic implications in most of them.

Cluster Analysis of Urban Acoustic Environments on Barcelona Sensor Network Data.

As cities grow in size and number of inhabitants, continuous monitoring of the environmental impact of sound sources becomes essential for the assessment of the urban acoustic environments. This requires the use of management systems that should be fed with large amounts of data captured by acoustic sensors, mostly remote nodes that belong to a wireless acoustic sensor network. These systems help city managers to conduct data-driven analysis and propose action plans in different areas of the city, for instance, to reduce citizens' exposure to noise. In this paper, unsupervised learning techniques are applied to discover different behavior patterns, both time and space, of sound pressure levels captured by acoustic sensors and to cluster them allowing the identification of various urban acoustic environments. In this approach, the categorization of urban acoustic environments is based on a clustering algorithm using yearly acoustic indexes, such as Lday, Levening, Lnight and standard deviation of Lden. Data collected over three years by a network of acoustic sensors deployed in the city of Barcelona, Spain, are used to train several clustering methods. Comparison between methods concludes that the k-means algorithm has the best performance for these data. After an analysis of several solutions, an optimal clustering of four groups of nodes is chosen. Geographical analysis of the clusters shows insights about the relation between nodes and areas of the city, detecting clusters that are close to urban roads, residential areas and leisure areas mostly. Moreover, temporal analysis of the clusters gives information about their stability. Using one-year size of the sliding window, changes in the membership of nodes in the clusters regarding tendency of the acoustic environments are discovered. In contrast, using one-month windowing, changes due to seasonality and special events, such as COVID-19 lockdown, are recognized. Finally, the sensor clusters obtained by the algorithm are compared with the areas defined in the strategic noise map, previously created by the Barcelona city council. The developed k-means model identified most of the locations found on the overcoming map and also discovered a new area.

Guías de práctica clínica de la Sociedad Española de Cardiología en tromboembolismo e hipertensión pulmonar / Guidelines of the Spanish Society of Cardiology for Pulmonary Thromboembolism and Hypertension

La hipertensión pulmonar primaria es una enfermedad de carácter progresivo, más frecuente en mujeres jóvenes y de mediana edad. Su etiología se desconoce, aunque existe una predisposición familiar hasta en un 6 por ciento de los casos. Las teorías patogénicas actuales se centran en la existencia de disfunción endotelial y fallos en los canales iónicos de las fibras musculares lisas del vaso. Las pruebas diagnósticas se dirigen a descartar las causas secundarias y a evaluar la gravedad de la enfermedad. El test vasodilatador agudo es imprescindible para la elección del tratamiento más adecuado. La anticoagulación oral está indicada en todos los pacientes. El trasplante de pulmón queda reservado a aquellos casos en los que fracasa el tratamiento médico. La septostomía auricular es un procedimiento paliativo útil en casos seleccionados. La hipertensión pulmonar tromboembólica crónica es una forma especial de hipertensión pulmonar secundaria; aunque indistinguible clínicamente de la hipertensión pulmonar primaria, su diagnóstico resulta crucial, ya que es posible su curación mediante la realización de tromboendarterectomía pulmonar. El tromboembolismo pulmonar es frecuente en pacientes hospitalizados, presentando elevadas tasas de mortalidad (el 30 por ciento en pacientes no tratados). El diagnóstico es difícil, ya que puede acompañar o simular otras enfermedades cardiopulmonares. Las pruebas diagnósticas no invasivas tienen una baja sensibilidad y especificidad. Nuevas alternativas como la determinación de dímero D o la TAC helicoidal incrementan la precisión diagnóstica. El tratamiento estándar consiste en la administración de heparina durante 5-10 días y posteriormente anticoagulantes orales durante 3-6 meses. La prevención con heparinas o dextranos en los pacientes de alto riesgo ha demostrado claros beneficios (AU)

La arteriografía en el trasplante renal / Arteriography in renal transplantation

Se presenta la experiencia de los estudios de trasplante renal del Instituto de Nefrología de La Habana en un período de 25 meses. Se plantea que esta investigación fue de gran utilidad en el posoperatorio inmediato para establecer el diagnóstico entre obstrucción vascular, necrosis tubular aguda y rechazo agudo precoz, y en evolución más tardía, para el estudio de la hipertensión arterial y algunos casos de rechazo. Se describen 12 diversas patologías agrupadas en vasculares puras, perenquimatovasculares y urológicas. Se detallan las lesiones encontradas en nuestra casuística en los casos de rechazo, hipertensión arterial y lesiones de vías excretoras (AU)