Spectral responsivity vs. action spectrum in digital photography

We propose an experimental and theoretical methodology based on spectroradiometric procedures to determine the spectral sensitivity of digital still cameras (DSC). The opto-electronic conversion spectral functions (OECSF's) are obtained from normalized digital level (NDL) vs. spectral exposure data, fitted by a typical sigmoidal transition curve. At this stage, we define spectral responsivity r(λ, H) and action spectrum a(λ, NDL), which are conceptual derivations of the general concept of spectral sensitivity of any image sensor. Then, the real spectral responsivity and action spectrum are represented as 3-dimensional functions, where r(λ, H = constant) and a(λ, NDL = constant) profiles are scaled relatively to determine the valid linear output range of the digital image capture device. This range would serve to design the colorimetric profile of the camera with CIE-1931 XYZ standard observer, which is considered as a linear color image sensor.This research was supported by the Comisión Interministerial de Ciencia y Tecnología (CICYT) (Spain) under grants TAP96-0887 and TAP99-0856

Resultados de la aplicación de algoritmos de manejo en la gestión clínica de un servicio de angiología y cirugía vascular. Análisis del período 1990 - 2001

Objetivo: Analizar el impacto de la gestión clínica en los indicadores basicos de calidad asistencial en un servicio de Cirugía Vascular durante un periodo de 10 años. Métodos: Analisis retrospectivo de los indicadores asistenciales del servicio de Angiología y Cirugía Vascular en el periodo 1990 - 2001 y la influencia que una guia de manejo clínico y la elaboración de unos estandares de calidad tienen sobre ellos. Se compara el periodo 1990 - 1994, previo a la aplicación de estas guias, con el periodo 1995 - 200 l. Resultados: Todos los indicadores de calidad asistencial analizados presentan una mejora evidente cuando se comparan ambos periodos. El nivel de seguridad asistencial médico-quirúrgico no se vio afectado por la aplicación de algoritmos de manejo y de guías de cuidados clínicos. Conclusiones: La gestión clínica de los servicos basada en el binomio coste - calidad puede asegurar la eficiencia de un servicio y optimizar los recursos sanitarios sin menoscabo de la calidad de los procedimientos asistenciales. Es posible definir el estandar de calidad por grupo de procedimientos, en función de la utilización de recursos hospitalarios y de las tasas de morbi-mortalidad

Arrhythmic syncope: From diagnosis to management

Arrhythmia; Electrophysiological study; MyocardiopathyArítmia; Estudi electrofisiològic; MiocardiopatiaArritmia; Estudio electrofisiológico; MiocardiopatíaSyncope is a concerning symptom that affects a large proportion of patients. It can be related to a heterogeneous group of pathologies ranging from trivial causes to diseases with a high risk of sudden death. However, benign causes are the most frequent, and identifying high-risk patients with potentially severe etiologies is crucial to establish an accurate diagnosis, initiate effective therapy, and alter the prognosis. The term cardiac syncope refers to those episodes where the cause of the cerebral hypoperfusion is directly related to a cardiac disorder, while arrhythmic syncope is cardiac syncope specifically due to rhythm disorders. Indeed, arrhythmias are the most common cause of cardiac syncope. Both bradyarrhythmia and tachyarrhythmia can cause a sudden decrease in cardiac output and produce syncope. In this review, we summarized the main guidelines in the management of patients with syncope of presumed arrhythmic origin. Therefore, we presented a thorough approach to syncope work-up through different tests depending on the clinical characteristics of the patients, risk stratification, and the management of syncope in different scenarios such as structural heart disease and channelopathies

Complicaciones vasculares tras cateterismo cardíaco

Objetivos: Establecer la incidencia de complicaciones vasculares tras un cateterismo cardíaco y determinar los factores que influyen en la aparición de los mismos. Material y métodos: Revisión retrospectiva de los 3723 cateterismos cardíacos realizados en nuestro hospital durante un período de 50 meses. Se recogieron 32 traumatismos vasculares, distribuidos entre pseudoaneurismas, hematomas o hemorragias incoercibles, fístulas arteriovenosas e isquemias agudas por trombosis arterial. Se realizó un analisis estadístico mediante tablas de contingencia (método de Jicuadrado, con corrección de Yates). Resultados: La incidencia anual de traumatismos vasculares se encuentra alrededor del 1 %. La incidencia de traumatismos tras un cateterismo terapéutico es ligeramente superior a la incidencia tras un cateterismo diagnóstico, sin presentar diferencias significativas. La edad media del grupo de pacientes con traumatismo vascular (grupo estudio) es de 64'2 ± 1 '9 años, ligeramente superior a la edad media del grupo sin traumatismo vascular (grupo control) (61 '1 - 0'2 años). En ambos grupos predominaban los varones, pero en el grupo estudio dicho predominio es sensi blemente inferior (p 0'012) . En el grupo estudio la incidencia de pacientes obesos es superior con respecto al grupo control (p 0'024). El abordaje por vía humeral (p 0'03), el diametro de cateter mayor al 8F (p 0'001) Y la anticoagulación tras el cateterismo (p<0'001) son factores favorecedores par la aparición de un traumatismo vascular tras un cateterismo cardíaco

Enantio- and diastereocontrol in intermolecular cyclopropanation reaction of styrene catalyzed by dirhodium(II) complexes with bulky ortho-metalated aryl phosphines

Enantiomerically pure dirhodium(II) complexes with ortho-metalated p-substituted aryl phosphines have been shown to be enantio- and diastereoselective in the cyclopropanation of styrene by ethyl diazoacetate. Enantioselectivities up to 91% and diastereoselectivities up to 90% are observed for ethyl cis-2-phenylcyclopropanecarboxylate.Estevan Estevan, Francisco, [email protected] ; Lahuerta Peña, Pascual, [email protected] ; Lloret Fillol, Julio, [email protected] ; Sanau Torrecilla, Mercedes, [email protected] ; Ubeda Picot, M Angeles, [email protected] ; Vila Gomez, Jaume Llorenc, [email protected]

Diagnosis of right bundle branch block: a concordance study

Bundle branch block; ConcordanceBloqueig de branca; ConcordançaBloqueo de rama; ConcordanciaBACKGROUND: Right bundle branch block is one of the most common electrocardiographic abnormalities. Most cases of right bundle branch block are detected in asymptomatic patients in primary care, so a correct interpretation of electrocardiograms (ECGs) at this level is necessary. The objective of this research is to determine the degree of concordance in the diagnosis of incomplete and complete right bundle branch block between four primary care researchers and a cardiologist. METHODS: The research design is a retrospective cohort study of patients over 18 years of ages of patients over 18 years of ages who underwent an ECG for any reason and were diagnosed with right bundle branch block by their physician. The physicians participating, 4 primary care researchers and a cardiologist were specialized in interpreting electrocardiographic records. The diagnosis of incomplete and complete right bundle branch block was recorded and other secondary variables were analysed. In case of diagnostic discordance between the researchers, the ECGs were reviewed by an expert cardiologist, who interpreted them, established the diagnosis and analysed the possible causes for the discrepancy. RESULTS: We studied 160 patients diagnosed with right bundle branch block by their general practise. The patients had a mean age of 64.8 years and 54% of them were men. The concordance in the diagnosis of incomplete right bundle branch block showed a Fleiss' kappa index (k) of 0.71 among the five researchers and of 0.85 among only the primary care researchers. The k for complete right bundle branch block was 0.93 among the five researchers and 0.96 among only the primary care researchers. CONCLUSION: The interobserver agreement in the diagnosis of right bundle branch block performed by physicians specialized in ECG interpretation (primary care physicians and a cardiologist) was very good. The variability was greater for the diagnosis of incomplete right bundle branch block

Cardiac monitoring for patients with palpitations

Monitoreo cardíaco; Grabadora de bucle; PalpitaciónCardiac monitoring; Loop recorder; PalpitationMonitorització cardíaca; Gravadora de bucle; PalpitacióPalpitations are one of the most common reasons for medical consultation. They tend to worry patients and can affect their quality of life. They are often a symptom associated with cardiac rhythm disorders, although there are other etiologies. For diagnosis, it is essential to be able to reliably correlate the symptoms with an electrocardiographic record allowing the identification or ruling out of a possible rhythm disorder. However, reaching a diagnosis is not always simple, given that they tend to be transitory symptoms and the patient is frequently asymptomatic at the time of assessment. In recent years, electrocardiographic monitoring systems have incorporated many technical improvements that solve several of the 24-h Holter monitor limitations. The objective of this review is to provide an update on the different monitoring methods currently available, remarking their indications and limitations, to help healthcare professionals to appropriately select and use them in the work-up of patients with palpitations

Accuracy of a Smartwatch to Assess Heart Rate Monitoring and Atrial Fibrillation in Stroke Patients

Accuracy; Atrial fibrillation; SmartwatchPrecisión; Fibrilación auricular; Reloj inteligentePrecisió; Fibril·lació auricular; Rellotge intel·ligentBackground: Consumer smartwatches may be a helpful tool to screen for atrial fibrillation (AF). However, validation studies on older stroke patients remain scarce. The aim of this pilot study from RCT NCT05565781 was to validate the resting heart rate (HR) measurement and the irregular rhythm notification (IRN) feature in stroke patients in sinus rhythm (SR) and AF. (2) Methods: Resting clinical HR measurements (every 5 min) were assessed using continuous bedside ECG monitoring (CEM) and the Fitbit Charge 5 (FC5). IRNs were gathered after at least 4 h of CEM. Lin’s concordance correlation coefficient (CCC), Bland-Altman analysis, and mean absolute percentage error (MAPE) were used for agreement and accuracy assessment. (3) Results: In all, 526 individual pairs of measurements were obtained from 70 stroke patients—age 79.4 years (SD ± 10.2), 63% females, BMI 26.3 (IQ 22.2–30.5), and NIHSS score 8 (IQR 1.5–20). The agreement between the FC5 and CEM was good (CCC 0.791) when evaluating paired HR measurements in SR. Meanwhile, the FC5 provided weak agreement (CCC 0.211) and low accuracy (MAPE 16.48%) when compared to CEM recordings in AF. Regarding the accuracy of the IRN feature, analysis found a low sensitivity (34%) and high specificity (100%) for detecting AF. (4) Conclusion: The FC5 was accurate at assessing the HR during SR, but the accuracy during AF was poor. In contrast, the IRN feature was acceptable for guiding decisions regarding AF screening in stroke patients.This study was funded by the Instituto de Salud Carlos III and the European Union (ERDF/ESF)—A way to build Europe (PI20/01210). Funding was also received in the framework of the “Digital Health Research Promotion Program: from the idea to the project” from the eHealth Center of the Universitat Oberta de Catalunya (UOC)

Proteins and pathways in atrial fibrillation and atrial cardiomyopathy underlying cryptogenic stroke

Atrial fibrillation (AF) is one of the most prevalent causes of cryptogenic stroke. Also, apart from AF itself, structural and remodelling changes in the atria might be an underlying cause of cryptogenic stroke. We aimed to discover circulating proteins and reveal pathways altered in AF and atrial cardiomyopathy, measured by left atrial volume index (LAVI) and peak atrial longitudinal strain (PALS), in patients with cryptogenic stroke. An aptamer array (including 1310 proteins) was measured in the blood of 20 cryptogenic stroke patients monitored during 28 days with a Holter device as a case-control study of the Crypto-AF cohort. Protein levels were compared between patients with (n = 10) and without AF (n = 10) after stroke, and the best candidates were tested in 111 patients from the same cohort (44 patients with AF and 67 without AF). In addition, in the first 20 patients, proteins were explored according to PALS and LAVI values. Forty-six proteins were differentially expressed in AF cases. Of those, four proteins were tested in a larger sample size. Only DPP7, presenting lower levels in AF patients, was further validated. Fifty-seven proteins correlated with LAVI, and 270 correlated with PALS. NT-proBNP was common in all the discovery analyses performed. Interestingly, many proteins and pathways were altered in patients with low PALS. Multiple proteins and pathways related to AF and atrial cardiomyopathy have been revealed. The role of DPP7 as a biomarker for stroke aetiology should be further explored. Moreover, the present study may be considered hypothesis-generatin

Life-threatening and life-saving inappropriate implantable cardioverter defibrillator shocks

An implantable cardioverter defibrillator (ICD) lead dislodgement into the right atrium is a dangerous situation, particularly in patients in atrial fibrillation because atrial fibrillation can be sensed as ventricular fibrillation and true ventricular fibrillation induced with an inappropriate shock. In the presence of shocks, ICD interrogation should be performed as soon as possible