Stabilization of unstable reentrant atrial tachycardias via fractionated continuous electrical activity ablation (CHAOS study)

Background: Unstable reentrant atrial tachycardias (ATs) (i.e. those with frequent circuit modification or conversion to atrial fibrillation) are challenging to ablate. We tested a strategy to achieve arrhythmia stabilization into mappable stable ATs based on the detection and ablation of rotors. Methods: All consecutive patients from May 2017 to December 2019 were included. Mapping was performed using conventional high-density mapping catheters (IntellaMap ORION, PentaRay NAV or Advisor HD Grid). Rotors were subjectively identified as fractionated continuous (or quasi-continuous) electrograms on 1–2 adjacent bipoles, without dedicated software. In patients without detectable rotors, sites with spatiotemporal dispersion (i.e. all the cycle length comprised within the mapping catheter) plus non-continuous fractionation on single bipoles were targeted. Ablation success was defined as conversion to a stable AT or sinus rhythm. Results: Ninety seven patients with reentrant ATs were ablated. Of these, 18 (18.6%) presented unstable circuits. 13 (72%) patients had detectable rotors (median 2 [1–3] rotors per patient); focal ablation was successful in 12 (92%). In the other 5 patients, 17 sites with spatiotemporal dispersion were identified and targeted. Globally, and excluding 1 patient with spontaneous AT stabilization, ablation success was achieved in 16/17 patients (94.1%). One-year freedom from atrial arrhythmias was similar between patients with unstable and stable ATs (66.7% vs. 65.8%, p = 0.946). Conclusions: Most unstable reentrant ATs show detectable rotors, identified as sites with single-bipole fractionated quasi-continuous signals, or spatiotemporal dispersion plus non-continuous fractionation. Ablation of these sites is highly effective to stabilize the AT or convert it into sinus rhythm

Long-term outcome after ablation of right atrial tachyarrhythmias after the surgical repair of congenital and acquired heart disease

[EN]Atrial myopathy, atriotomies, and fibrotic scars are the pathophysiological substrate of lines of conduction block, promoting atrial macroreentry. The aim of this study was to determine the acute and long-term outcome of radiofrequency catheter ablation (RFCA) for right atrial tachyarrhythmia (AT) in adults after cardiac surgery for congenital heart disease (CHD) and acquired heart disease (AHD) and predictors of these outcomes. Clinical records of adults after surgery for heart disease undergoing RFCA of right-sided AT were analyzed retrospectively. Multivariate analyses identified clinical and procedural factors predicting acute and long-term outcomes. A total of 372 patients (69% men; age 61 ± 15 years) after surgical repair of CHD (n = 111) or AHD (n = 261) were studied. Cavotricuspid isthmus-dependent atrial flutter (CTI-AFL) was observed in 300 patients and non-CTI-AFL in 72 patients. Ablation was successful in 349 cases (94%). During a mean follow-up of 51 ± 30 months, recurrences were observed in 24.5% of patients. Multivariate analysis showed that non-CTI-AFL (hazard ratio [HR] 1.78, 95% confidence interval [CI] 1.1 to 2.9) and CHD (HR 1.75, 95% CI 1.07 to 2.9) were independent predictors of long-term recurrences. Multivariate analysis showed that female gender (HR 2.29, 95% CI 1.6 to 3.3), surgery for AHD (HR 95% 2.31, 95% CI 1.5 to 3.7), and left atrial dilatation (HR 2.1, 95% CI 1.3 to 3.2) were independent predictors of long-term atrial fibrillation. In conclusion, RFCA of right-sided AT after cardiac surgery is associated with high acute success rates and significant long-term recurrences. Non-CTI-dependent AFL and surgery for CHD are at higher risk of recurrence. Atrial fibrillation is common during follow-up, particularly in patients with AHD and enlarged left atrium

Impact of previous cardiac surgery on long-term outcome of cavotricuspid isthmus-dependent atrial flutter ablation

[EN]The aim of this study was to determine the acute and long-term outcome of radiofrequency catheter ablation (RFCA) for cavotricuspid isthmus-dependent atrial flutter (CTI-AFL) in adults with and without previous cardiac surgery (PCS), and predictors of these outcomes. Structural alterations of the anatomical substrate of the CTI-AFL are observed in post-operative patients, and these may have an impact on the acute success of the ablation and in the long-term. Clinical records of consecutive adults undergoing RFCA of CTI-AFL were analysed. Two main groups were considered: No PCS and PCS patients, who were further subdivided into acquired heart disease (AHD: ischaemic heart disease and valvular/mixed heart disease) and congenital heart disease [CHD: ostium secundum atrial septal defect (OS-ASD) and complex CHD]. Multivariate analysis identified clinical and procedural factors that predicted acute and long-term outcomes. A total of 666 patients (73% men, age 65 ± 12 years) were included: 307 of them with PCS. Ablation was successful in 647 patients (97%), 96% in the PCS group and 98% in the No PCS group (P = 0.13). Regression analysis showed that surgically corrected complex CHD was related to failure of the procedure [odds ratio 5.6; 95% confidence interval (CI) 1.6-18, P = 0.008]. After a follow-up of 45 ± 15 months, recurrences were observed in 90 patients (14%), more frequently in the PCS group: absolute risk of recurrence 18 vs. 10.5%, relative risk 1.71, 95% CI: 1.2-2.5, P = 0.006. Multivariate analysis indicated that the types of PCS [OS-ASD vs. No PCS: hazard ratio (HR) 2.57; 95% CI: 1.1-6.2, P = 0.03 and complex CHD vs. No PCS: HR 2.75; 95% CI: 1.41-5.48, P = 0.004], female gender (HR 1.55; 95% CI: 1.04-2.4, P = 0.048), and severe LV dysfunction (HR 1.36; 95% CI: 1.06-1.67, P = 0.04) were independent predictors of long-term recurrence. Radiofrequency catheter ablation of CTI-AFL after surgical correction of AHD and CHD is associated with high acute success rates. The severity of the structural alterations of the underlying heart disease and consequently the type of surgical correction correlates with higher risk for recurrence

Catheter ablation vs. antiarrhythmic drug treatment of persistent atrial fibrillation : A multicentre, randomized, controlled trial (SARA study)

BackgroundCatheter ablation (CA) is a highly effective therapy for the treatment of paroxysmal atrial fibrillation (AF) when compared with antiarrhythmic drug therapy (ADT). No randomized studies have compared the two strategies in persistent AF. The present randomized trial aimed to compare the effectiveness of CA vs. ADT in treating persistent AF.Methods and resultsPatients with persistent AF were randomly assigned to CA or ADT (excluding patients with long-standing persistent AF). Primary endpoint at 12-month follow-up was defined as any episode of AF or atrial flutter lasting >24 h that occurred after a 3-month blanking period. Secondary endpoints were any atrial tachyarrhythmia lasting >30 s, hospitalization, and electrical cardioversion. In total, 146 patients were included (aged 55 ± 9 years, 77% male). The ADT group received class Ic (43.8%) or class III drugs (56.3%). In an intention-to-treat analysis, 69 of 98 patients (70.4%) in the CA group and 21 of 48 patients (43.7%) in the ADT group were free of the primary endpoint (P = 0.002), implying an absolute risk difference of 26.6% (95% CI 10.0-43.3) in favour of CA. The proportion of patients free of any recurrence (>30 s) was higher in the CA group than in the ADT group (60.2 vs. 29.2%; P < 0.001) and cardioversion was less frequent (34.7 vs. 50%, respectively; P = 0.018).ConclusionCatheter ablation is superior to medical therapy for the maintenance of sinus rhythm in patients with persistent AF at 12-month follow-up.Clinical Trial Registration InformationNCT00863213 (http://clinicaltrials.gov/ct2/show/NCT00863213)

Morbid liver manifestations are intrinsically bound to metabolic syndrome and nutrient intake based on a machine-learning cluster analysis

Metabolic syndrome (MetS) is one of the most important medical problems around the world. Identification of patient ' s singular characteristic could help to reduce the clinical impact and facilitate individualized management. This study aimed to categorize MetS patients using phenotypical and clinical variables habitually collected during health check-ups of individuals considered to have high cardiovascular risk. The selected markers to categorize MetS participants included anthropometric variables as well as clinical data, biochemical parameters and prescribed pharmacological treatment. An exploratory factor analysis was carried out with a subsequent hierarchical cluster analysis using the z-scores from factor analysis. The first step identified three different factors. The first was determined by hypercholesterolemia and associated treatments, the second factor exhibited glycemic disorders and accompanying treatments and the third factor was characterized by hepatic enzymes. Subsequently four clusters of patients were identified, where cluster 1 was characterized by glucose disorders and treatments, cluster 2 presented mild MetS, cluster 3 presented exacerbated levels of hepatic enzymes and cluster 4 highlighted cholesterol and its associated treatments Interestingly, the liver status related cluster was characterized by higher protein consumption and cluster 4 with low polyunsaturated fatty acid intake. This research emphasized the potential clinical relevance of hepatic impairments in addition to MetS traditional characterization for precision and personalized management of MetS patients

Utilidad diagnóstica de un protocolo de ecografía transesofágica en el período perioperatorio del trasplante cardiaco ortotópico

Los objetivos de esta Tesis son, en primer lugar, conocer la rentabilidad de un protocolo de estudio transesofágico en el periodo perioperatorio del trasplante cardiaco realizado con la técnica quirúrgica convencional, con especial atención a las complicaciones tromboembólicas. ¨Y en segundo lugar, estudiar los factores relacionados con la presencia de trombos auriculares y contraste ecocardiográfico espontáneo en los estudios transesofágicos realizados en el periodo perioperatorio

Desarrollo de un proceso de transferencia tecnológica y gestión de la innovación en la Facultad de Ciencias Físicas y Matemáticas de la Universidad de Chile

Ingeniero Civil IndustrialEl presente Trabajo de título se enmarca en el contexto del programa Innova CORFO: Nueva ingeniería para 2030, adjudicado por la Universidad de Chile, que tiene como objetivo elaborar, implementar y dar seguimiento a planes estratégicos, destinados a transformar bajo estándares internacionales las escuelas de ingeniería chilenas, en los ámbitos de investigación aplicada, desarrollo y transferencia tecnológica, innovación y emprendimiento. El objetivo central es proponer un rediseño del proceso de Transferencia Tecnológica en la Facultad de Ciencias Físicas y Matemáticas (FCFM) de la Universidad de Chile con el fin de aumentar el emprendimiento académico mediante el estudio y análisis de proyectos de transferencia tecnológica. Para lograr dicho objetivo, en una primera etapa se realizó un benchmarking de buenas prácticas nacionales e internacionales, identificando las estructuras y mecanismos relevantes que utilizan las universidades para facilitar los procesos de Transferencia Tecnológica. Luego, se realizó un análisis de los actores, estructura, financiamiento y legislación involucrada en el proceso de transferencia de la FCFM. A partir de esto, se determinó que no existe un proceso estandarizado para generar emprendimientos desde de los resultados de investigación. No obstante, la Facultad tiene un gran volumen de investigación básica y aplicada, y se relaciona con la industria principalmente a través de sus centros de investigación. Posteriormente, se realizaron entrevistas a autoridades relevantes como académicos, investigadores, directores de unidades de transferencia tecnológica y personal administrativo de la Facultad a partir de las cuales se obtuvieron percepciones y visiones. Finalizado este estudio, las dos conclusiones principales son: (i) la generación de Spin-off es una alternativa bien percibida por los expertos, dado su potencial formativo, sobretodo cuando son liderados por alumnos. Además, que la investigación aplicada esta sujeta al financiamiento que se pueda acceder, el cual es primordialmente de origen estatal y (ii) que las relaciones entre la Universidad y la empresa no se dan en forma natural, principalmente por diferencias en sus objetivos. En base a lo anterior, se estudiaron proyectos de Transferencia Tecnológica desarrollados en la FCFM y se identificaron los factores críticos que inciden en este tipo de proyectos. Finalmente, se propone un rediseño de los procesos de Transferencia Tecnológica a través de la creación de una Oficina de Relación con la Industria (OPI), que tiene como objetivos mejorar sistemáticamente los procesos administrativos, incrementar los proyectos con potencial innovador, aumentar los proyectos de transferencia tecnológica y sistematizar la relación con la industria. La evaluación económica de la propuesta indica que la OPI requeriría de un subsidio de CLP $ 332.484.000 para su funcionamiento durante los primeros cuatro años, utilizando una tasa de descuento de 12%