Antegrade or Retrograde Accessory Pathway Conduction: Who Dies First?

A 36 year-old man with Wolff Parkinson White syndrome due to a left-sided accessory pathway (AP) was referred for catheter ablation. Whether abolition of antegrade and retrograde AP conduction during ablation therapy occurs simultaneously, is unclear. At the ablation procedure, radiofrequency delivery resulted in loss of preexcitation followed by a short run of orthodromic tachycardia with eccentric atrial activation, demonstrating persistence of retrograde conduction over the AP after abolition of its antegrade conduction. During continued radiofrequency delivery at the same position, the fifth non-preexcitated beat failed to conduct retrogradely and the tachycardia ended. In this case, antegrade AP conduction was abolished earlier than retrograde conduction

Radiofrequency catheter ablation of frequent premature ventricular contractions using ARRAY multi-electrode balloon catheter

Background: The noncontact mapping system facilitates the mapping of premature ventricular contractions (PVCs) and ventricular tachycardia (VT) using a 64-electrode expandable balloon catheter (ARRAY, St. Jude Medical). The aim of this study is to analyze the results and follow-up of the PVC ablation using this system. Methods and results: Prospective and consecutive patients with frequent PVCs (6,000 or more) or monomorphic VT, suspected to be originated on the right ventricular outflow tract (RVOT), were included. The balloon catheter was positioned in the RVOT. Eighteen patients, 9 women, mean age 48 years (youngest/oldest 19–65) were included. Sixteen patients presented no structural heart disease. The origin of the arrhythmia was RVOT (n = 15), right ventricular inflow tract (n = 1), and left ventricular outflow tract (n = 2). Acute success was achieved in 15 patients; in 2 patients radiofrequency was not applied due to security reasons (origin site close to left coronary artery origin). The mean follow-up was 15 months (min. 4, max. 26); 13 patients presented abolition of the arrhythmia without drugs and 1 patient required antiarrhythmic drugs for arrhythmia control (previously ineffective). As an only complication, a femoral artery-venous fistula was observed. Conclusions: The noncontact mapping system using a multielectrode balloon allows right ventricular arrhythmia treatment with a high rate of efficacy and safety

The first Latin American Catheter Ablation Registry

Aims To assess the results of transcatheter ablation of cardiac arrhythmias in Latin America and establish the first Latin American transcatheter ablation registry.Methods and results All ablation procedures performed between 1 January and 31 December 2012 were analysed retrospectively. Data were obtained on the characteristics and resources of participating centres (public or private institution, number of beds, cardiac surgery availability, type of room for the procedures, days per week assigned to electrophysiology procedures, type of fluoroscopy equipment, availability and type of electroanatomical mapping system, intracardiac echo, cryoablation, and number of electrophysiologists) and the results of 17 different ablation substrates: atrio-ventricular node reentrant tachycardia, typical atrial flutter, atypical atrial flutter, left free wall accessory pathway, right free wall accessory pathway, septal accessory pathway, right-sided focal atrial tachycardia, left-sided focal atrial tachycardia, paroxysmal atrial fibrillation, non-paroxysmal atrial fibrillation, atrio-ventricular node, premature ventricular complex, idiopathic ventricular tachycardia, post-myocardial infarction ventricular tachycardia, ventricular tachycardia in chronic chagasic cardiomyopathy, ventricular tachycardia in congenital heart disease, and ventricular tachycardias in other structural heart diseases. Data of 15 099 procedures were received from 120 centres in 13 participating countries (Argentina, Bolivia, Brazil, Chile, Colombia, Cuba, El Salvador, Guatemala, Mexico, Peru, Dominican Republic, Uruguay, and Venezuela). Accessory pathway was the group of arrhythmias most frequently ablated (31%), followed by atrio-ventricular node reentrant tachycardia (29%), typical atrial flutter (14%), and atrial fibrillation (11%). Overall success was 92% with the rate of global complications at 4% and mortality 0.05%.Conclusion Catheter ablation in Latin America can be considered effective and safe.Hosp Privado Sur, Serv Electrofisiol, RA-8000 Bahia Blanca, Buenos Aires, ArgentinaCtr Privado Cardiol, San Miguel de Tucuman, ArgentinaEscola Paulista Med, São Paulo, BrazilCES Cardiol & Clin Amer, Serv Electrofisiol, Medellin, ColombiaISSSTE, Ctr Med Nacl 20 Noviembre, Mexico City, DF, MexicoFMUSP, Inst Coracao, São Paulo, BrazilUnidad Especializada Arritmias, Caracas, VenezuelaInst Nacl Cardiovasc INCOR EsSalud, Lima, PeruCEMIC, Buenos Aires, DF, ArgentinaHosp Nacl Alejandro Posadas, Buenos Aires, DF, ArgentinaInst Cardiol Corrientes, Corrientes, ArgentinaInst Cardiovasc Buenos Aires, Buenos Aires, DF, ArgentinaEscola Paulista Med, São Paulo, BrazilWeb of Scienc

Application and Comparison of the CHADS2 and CHA2DS2-VASc Risk Scores in a Population with Atrial Fibrillation

IntroductionThe CHADS2 score and the CHA2DS2-VASc score recently adopted by the medicalcommunity have been developed with international registry data and are widely usedin clinical practice. However, they have not been evaluated in national registries.ObjectivesThe aims of this study were first to evaluate the predictive power of the CHADS2and CHA2DS2-VASc stroke risk scores in the Atrial Fibrillation Registry conductedby the Argentine Society of Cardiology Research Area and second to compare bothscoring systems.MethodsThe Atrial Fibrillation Registry of 2001 was a multicenter, prospective study of allconsecutive patients with chronic atrial fibrillation (permanent and persistent)treated in 70 medical centers in Argentina. Demographic data, socioeconomic characteristics,background and clinical features were obtained. A 2-year follow-up wasperformed to assess stroke rate. For the present analysis patients without anticoagulanttreatment were selected. In this population, the two risk score systems wereassessed; a ROC curve was built for each score (reported as C statistic) and bothscoring systems were compared.ResultsThe study population consisted of 303 patients (49.3 %) not receiving anticoagulanttherapy. The stroke rate in the selected population was 9.5%. Both scoring systemspredicted significant stroke risk.The stroke rate increased as the CHADS2 and the CHA2DS2-VASc scores were higher,and were similar in both risk scales.The CHADS2 and CHA2DS2-VASc scores had C statistic values of 0.67 (0.55-0.78)and 0.69 (0.59 to 0.78), respectively, without significant differences between them.The score analyses divided into three risk profiles -low, moderate and high- revealedthat the predictive power decreased markedly. The C statistic of the CHADS2 was0.63 (95% CI 0.57-0.68) and that of the CHA2DS2-VASc score was 0.57 (95% CI 0.51-0.62, with a slightly better predictive trend for the CHADS2 score but without statisticalsignificance.ConclusionsThe two scoring systems used to predict stroke in an Argentine population of patientswith persistent and permanent atrial fibrillation have a similar predictivepower comparable to results reported in the literature.Introducción:El puntaje   CHADS2 y  el recientemente adoptado por la comunidad médica     CHA2DS2 VASc Han sido confeccionados con datos de registros internacionales y son ampliamente usados en la práctica  clínica, sin embargo, no han sido testeados en registros nacionales.Objetivo:El objetivo del presente estudio es evaluar el poder de predicción de los puntajes  de riesgo de ACV  (CHADS2 y CHA2DS2 VASc  ) en el registro de fibrilación auricular realizado por área de investigación de nuestra sociedad y comparar ambos sistemas de puntajes.Métodos:El registro de fibrilación auricular fue un estudio Multicéntrico y prospectivo de todos los pacientes consecutivos asistidos con Fibrilación Auricular Crónica (permanente y persistente) en 70 centros médicos de Argentina realizado en año 2001.Se obtuvieron los datos demográficos, las características socioeconómicas, los antecedentes y las características clínicas de la población con fibrilación auricular crónica (permanente y persistente).Se realizó un seguimiento a 2 años evaluando la tasa de  ACV . Se seleccionaron los pacientes sin tratamiento anticoagulante para el análisis. Se Testeo en esta población los dos sistemas de puntajes de riesgo confeccionándose una curva de ROC para cada puntaje (informándose como C estadístico) y realizándose un comparación entre ambos sistemas de puntajes.Resultados:El 49, 3 % (303 pacientes) de los pacientes seguidos no recibían tratamiento anticoagulante y esta fue nuestra población en estudio. La tasa de ACV en la población seleccionada  fue del  9,5 %.Los dos sistemas de puntajes de riesgo predijeron el ACV significativamente.En la tabla se ve la tasa de ACV por cada punto sumado. 012345678CHADS22,6%5.1%9,1%14,2%12,5%50%0%  CHADVASC0%2,8%6.3%1,4%14,4%20%7,6%22,2%  El C estadístico para ACV del CHADS2 fue de 0,67 (0,55-0,78) y C estadístico para ACV del CHA2DS2 VASc fue 0,69 (0,59-0,78)  sin diferencias significativas entre ambos. Conclusiones En una población  con fibrilación auricular de la república Argentina se observó que los 2 sistemas de puntajes  de predicción de ACV en pacientes con FA permanente y persistente  tienen un similar poder de predicción entre ellos y similar al reportado en la literatura

Brugada electrocardiographic pattern induced by fever

Brugada syndrome is a major cause of sudden death in young adults. Fever has been described to induce a Brugada-type electrocardiogram in asymptomatic patients with a negative family history, to disclose Brugada syndrome and to increase the risk of death and induce T wave alternans in patients with diagnosed Brugada syndrome. Risk stratification is challenging and demands a careful evaluation. Here we present 2 case reports and review the literature