Doble tormenta tiroidea y arrítmica en una gestante con múltiples taquicardias refractarias mediadas por un haz de kent intermitente ablacionado exitosamente

La tormenta tiroidea es un estado crítico y poco frecuente que condiciona la disfunción de múltiples órganos por el efecto del exceso de las hormonas tiroideas, esta disfunción endócrina tiene una elevada mortalidad y genera manifestaciones típicas como la taquicardia, fiebre, alteraciones gastrointestinales, cardiovasculares y del sistema nervioso central. El embarazo se ha asociado con un incremento en la incidencia de arritmias. Necesitan un tratamiento inmediato con drogas antiarrítmicas, cardioversión eléctrica o cesárea de urgencia. El WPW es una anormalidad cardiaca congénita que consiste en la presencia de un haz anómalo (Haz de Kent) que evita el sistema normal de conducción uniendo directamente aurículas y ventrículos. Veremos el caso de una gestante de 32 semanas que presenta un cuadro de tormenta tiroidea y múltiples episodios de taquicardia paroxística supraventricular (TPS), de tórpida y sombría evolución clínica mediada por un haz anómalo de Kent intermitente. Es evidente que la tormenta tiroidea en el contexto de la gestación produjo cambios en las propiedades electrofisiológicas del haz anómalo de Kent intermitente lo cual propició el desarrollo de múltiples taquicardias paroxísticas supraventriculares refractarias a la cardioversión eléctrica y farmacológica. Tampoco mejoró con la tiroidectomía total, solamente cedió por completo con la ablación por catéter de radiofrecuencia del haz anómalo de Kent.

Thyroid storm is a critical and infrequent state that conditions the dysfunction of multiple organs due to the effect of excess thyroid hormones. This endocrine dysfunction has a high mortality and generates typical manifestations such as tachycardia, fever, gastrointestinal, cardiovascular and heart disorders, and the central nervous system. Pregnancy has been associated with an increased incidence of arrhythmias. They need immediate treatment with antiarrhythmic drugs, electrical cardioversion, or emergency caesarean section. WPW is a congenital cardiac abnormality that consists of the presence of an abnormal bundle (Kent bundle) that prevents the normal conduction system, directly joining the atria and ventricles. We will see the case of a 32-week pregnant woman who presented symptoms of thyroid storm and multiple episodes of paroxysmal supraventricular tachycardia (PST), with a torpid clinical course mediated by an abnormal intermittent Kent bundle. It is evident that the thyroid storm in the context of pregnancy produced changes in the electrophysiological properties of the intermittent Kent bundle, which led to the development of multiple PST refractory to electrical and pharmacological cardioversion. Moreover, it also did not improve with total thyroidectomy, only resolved completely with radiofrequency catheter ablation of the Kent bundle.

SparkleMap-based left atrial flutter mapping and ablation.

Ablation of atypical left atrial flutters (LAF) is very challenging due to the complexity of the underlying atrial substrate and diverse arrhythmia mechanisms. The interpretation of the arrhythmia mechanism is usually difficult, even using advanced three-dimensional (3D) mapping systems. SparkleMap is a novel mapping algorithm that displays each electrogram as a green dot that lights up at the point corresponding to the local activation time, superimposed either on the substrate or the local activation time 3D-maps. It is not affected by the setting of the "window of interest" and there is no need for user post-processing. We present the case of patient with a persistent atypical LAF in whom we tested the concept of complex arrhythmia interpretation exclusively based on the analysis of the substrate and evaluation of SparkleMap-derived wavefront propagation. We describe the workflow for map collection and the systematic approach for arrhythmia interpretation that resulted in the identification of a dual loop perimitral mechanism with a common slow conducting isthmus inside a scar at the septum/anterior atrial wall. This new method of analysis enabled the use of a specifically targeted and precise approach for ablation, with restoration of sinus rhythm within five seconds of radiofrequency application. After 18 months of follow-up, the patient remains free from recurrences, without anti-arrhythmic medication. This case report exemplifies how helpful new mapping algorithms can be in the interpretation of the arrhythmia mechanism in patients with complex LAF. It also suggests an innovative workflow to integrate the SparkleMap into the mapping approach.

Flutter auricular en neonatologia. reporte de caso / Atrial flutter in neonatology. Case Report

El flutter auricular es la taquicardia confinada al atrio más frecuente en la edad neonatal, su adecuado tratamiento requiere un diagnóstico precoz. La posibilidad de presentar efectos adversos con los fármacos antiarrítmicos en recién nacidos es alta, por lo que se debe evitar el manejo empírico de la taquicardia en éste grupo etario. Se presenta el caso de un recién nacido con flutter auricular en corazón sano, que respondió favorablemente a las medidas farmacológicas convencionales, con buena evolución a mediano plazo.

Atrial flutter is the atrial confined tachycardia more frequent in the neonatal age, its adequate treatment requires an early diagnosis. The possibility of presenting adverse effects with antiarrhythmic drugs in newborns is high, so the empirical management of tachycardia should be avoided in this age group. We present the case of a newborn with atrial flutter in healthy heart, who responded favorably to conventional pharmacological measures, with good evolution in the medium term.

Flutter auricular neonatal: presentación de tres casos / Neonatal atrial flutter: Presentation of three cases

Resumen Introducción: El flutter auricular es un tipo poco frecuente de arritmia fetal y neonatal. A pesar de que puede conducir a graves morbilidades, como hidrops fetal o incluso el fallecimiento, el diagnóstico y tratamiento precoz confieren un buen pronóstico a la mayoría de los casos. Pacientes y métodos: Se presentan tres casos de flutter auricular, dos de inicio en periodo fetal y uno en periodo neonatal, y se revisa la literatura en relación con las características clínicas, diagnósticas y terapéuticas del flutter auricular fetal y neonatal. Resultados y discusión: En el flutter auricular fetal la terapia materna con fármacos antiarrítmicos es el tratamiento más empleado durante la gestación. El tratamiento postnatal más utilizado es la cardioversión eléctrica sincronizada. El flutter auricular no suele asociar cardiopatía estructural; la recidiva neonatal es poco habitual y normalmente no precisa la administración de tratamiento profiláctico.

Abstract Introduction: Atrial flutter is a rare type of fetal and neonatal arrhythmia. Although it can lead to serious morbidities such as fetal hydrops or even death, diagnosis and early treatment confer a good prognosis in most cases. Patients and methods: Three cases of atrial flutter are presented, two of which start in the fetal period and one in the neonatal period. The literature is reviewed in relation to the clinical, diagnostic and therapeutic characteristics of fetal and neonatal atrial flutter. Results and discussion: In fetal atrial flutter maternal therapy with antiarrhythmic drugs is the most used treatment during pregnancy. The most used postnatal treatment is synchronized electrical cardioversion. Atrial flutter does not usually associate structural heart disease, neonatal recurrence is uncommon and usually does not require prophylactic treatment.

A new electrophysiologic triad for identification and localization of the critical isthmus in atrial flutter.

INTRODUCTION: Atypical atrial flutter (AFL) is a supraventricular arrhythmia that can be treated with catheter ablation. However, this strategy yields suboptimal results and the best approach is yet to be defined. Carto® electroanatomical mapping (EAM) version 7 displays a histogram of the local activation times (LAT) of the tachycardia cycle length (TCL), in addition to activation and voltage maps. Using these EAM tools, the study aimed to assess the ability of an electrophysiologic triad to identify and localize the critical isthmus in AFL. METHODS: Retrospective analysis using Carto® EAM of a single center registry of individuals who underwent left AFL ablation over one year. Subjects with non-left AFL, no high-density EAM, under 2000 points or no left atrium wall or structure mapping were excluded. Sites where arrhythmia is terminated via ablation were compared to an electrophysiologic triad comprising areas of low-voltage (0.05 to 0.3 mV), deep histogram valleys (LAT-valleys) with less than 20% density points relative to the highest density zone and a prolonged LAT-valley duration, which included 10% or more of the TCL. The longest LAT-valley was designated as the primary valley, while additional valleys were named as secondary. RESULTS: A total of nine subjects (six men, median age 75, interquartile range 71-76 years) were included. All patients presented with left AFL and 66% had a history of ablation for atrial fibrillation and/or flutter. The median TCL and collected points were 254 ms (220-290) and 3300 (IQR 2410-3926) points, respectively. All individuals with AFL presented with at least one LAT-valley on the analyzed histograms, which corresponded to heterogeneous low voltage areas (0.05 to 0.3 mV) and affected more than 10% of TCL. Six of the nine patients presented with a secondary LAT-valley. All arrhythmias were terminated successfully following radiofrequency ablation at the primary LAT-valley location. After a minimum three-month follow-up all patients remained in sinus rhythm. CONCLUSION: An electrophysiologic triad identified the critical isthmus in AFL for all patients. Further studies are needed to assess the usefulness of this algorithm in improving catheter ablation outcomes.

Late atypical atrial flutter after ablation of atrial fibrillation. / Flutter auricular atípico tardio após ablação de fibrilhação auricular.

Cardiac surgery for structural heart disease (often involving the left atrium) and radiofrequency catheter ablation of atrial fibrillation have led to an increased incidence of regular atrial tachycardias, often presenting as atypical flutters. This type of flutter is particularly common after pulmonary vein isolation, especially after extensive atrial ablation including linear lesions and/or defragmentation. The authors describe the case of a 51-year-old man, with no relevant medical history, referred for a cardiology consultation in 2009 for paroxysmal atrial fibrillation. After failure of antiarrhythmic therapy, he underwent catheter ablation, with criteria of acute success. Three years later he again suffered palpitations and atypical atrial flutter was documented. The electrophysiology study confirmed the diagnosis of atypical left flutter and reappearance of electrical activity in the right inferior pulmonary vein. This vein was again ablated successfully and there has been no arrhythmia recurrence to date. In an era of frequent catheter ablation it is essential to understand the mechanism of this arrhythmia and to recognize such atypical flutters.

Remote magnetic navigation for ablation of typical atrial flutter: Long-term results.

INTRODUCTION AND AIM: Remote magnetic navigation has proved to be effective in the ablation of most supraventricular and ventricular arrhythmias. Initial studies reported worse results with this system compared to conventional ablation for atrial flutter. The aim of this study was to assess the acute and long-term success of atrial flutter ablation with remote magnetic navigation and to retrospectively compare the results obtained with an 8-mm tip catheter versus an irrigated catheter. METHODS: We studied 38 consecutive patients, mean age 61 ± 15 years, 28 male, who underwent ablation of typical atrial flutter with the Niobe II remote magnetic navigation system (Stereotaxis). Ablation was performed with an 8-mm tip catheter in 17 patients and with an irrigated-tip catheter in 21 patients. Acute success was defined as the presence of bidirectional isthmus block, and long-term success as absence of symptoms and atrial flutter during Holter monitoring. RESULTS: Bidirectional isthmus block was achieved in 37 patients (97%), and the success rate was similar in both groups. Total procedure time was not significantly different between the groups but fluoroscopy time was shorter in the irrigated tip group (13.4 ± 3.7 min vs. 6 ± 4.4 min; p<0.01). The number of applications and total radiofrequency time did not differ. There were no complications. During a follow-up of 32 ± 19 months there were two relapses, one in each group. CONCLUSIONS: The Niobe II remote control system for ablation of typical atrial flutter is safe and effective in both the short and long term. The 8-mm and irrigated-tip catheters showed similar safety and efficacy.

Taquicardiomiopatía: una causa reversible y poco reconocida de falla cardíaca / Tachycardiomyopathy: a reversible little known cause of heart failure

Se presenta el caso de una mujer de 74 años de edad, con síndrome de falla cardíaca, antecedente de enfermedad coronaria con revascularización percutánea previa y flutter auricular con respuesta ventricular rápida sin adecuado control con betabloqueadores y antiarrítmicos; tenía dilatación progresiva del ventrículo izquierdo, deterioro de la función sistólica y de la fracción de eyección hasta 18%, luego del episodio de arritmia incesante. Se demostró en la angiografía coronaria estenosis moderada a grave de los stents previamente implantados en las arterias descendente anterior y circunfleja, por lo cual se implantaron stents medicados. Posteriormente se hizo cardioversión eléctrica exitosa y cuatro semanas después permanecía en ritmo sinusal con recuperación de la función ventricular, evidenciada por la normalización de la fracción de eyección del ventrículo izquierdo, lo que corroboró la presunción diagnóstica de taquicardiomiopatía.

We report the case of a 74 year-old woman with heart failure syndrome, history of coronary artery disease with percutaneous revascularization and atrial flutter with rapid ventricular response without adequate control with beta-blockers and antiarrhythmic therapy, dilated left ventricle with impaired systolic function and ejection fraction of 18%; she had stent restenosis in the left anterior descending and the circumflex arteries. Medicated stents were implanted. Successful electrical cardioversion was performed and four weeks later she remained in sinus rhythm; ventricular function was normalized with ejection fraction of 60%, which corroborated the presumptive diagnosis of tachycardiomyopathy.

[Wide QRS tachycardia preceded by pacemaker spikes]. / Taquicardias de complejo QRS ancho precedidas de espiga de marcapasos.

The differential diagnosis and therapeutic management of wide QRS tachycardia preceded by pacemaker spike is presented. The pacemaker-mediated tachycardia, tachycardia fibrillo-flutter in patients with pacemakers, and runaway pacemakers, have a similar surface electrocardiogram, but respond to different therapeutic measures. The tachycardia response to the application of a magnet over the pacemaker could help in the differential diagnosis, and in some cases will be therapeutic, as in the case of a tachycardia-mediated pacemaker. Although these conditions are diagnosed and treated in hospitals with catheterization laboratories using the application programmer over the pacemaker, patients presenting in primary care clinic and emergency forced us to make a diagnosis and treat the haemodynamically unstable patient prior to referral.

Flutter auricular atípico en un niño con corazón estructuralmente sano / Atypical atrial flutter in a child with structurally normal heart

El flutter auricular es una causa infrecuente de taquicardia supraventricular en la edad pediátrica, con una incidencia de 0,01%, cifra subestimada por la baja tasa de sospecha clínica. Se presenta el caso de un niño con la asociación más rara de flutter auricular: debut en edad escolar, corazón estructuralmente sano y circuito de re-entrada localizado en aurícula izquierda. El tratamiento correcto de la taquicardia supraventricular fue importante para el adecuado diagnóstico y manejo a largo plazo de la arritmia.

Atrial flutter is an uncommon cause of supraventricular tachycardia in children, with an incidence of 0.01%, which is underestimated by the low rate of clinical suspicion. The case of a child with the rare association of atrial flutter is presented: school-age debut, structurally normal heart, and reentry circuit located in the left atrium. Correct treatment of supraventricular tachycardia was important for adequate diagnosis and long-term management of the arrhythmia.

Posible valor pronóstico de la fibrilación y el flutter auricular en el síndrome de Brugada / Possible prognostic value of atrial fibrillation and atrial flutter in Brugada syndrome

Objetivo: Analizar el riesgo específico para las variables: patrón tipo 1 espontáneo, patrón tipo 1 inducido, patrón tipo 1 con variabilidad espontánea, síncope, antecedente de muerte súbita familiar, fibrilación auricular y flutter auricular, con el desarrollo subsecuente de eventos arrítmicos malignos. Métodos: Se analizaron retrospectivamente 43 pacientes con síndrome de Brugada (90% hombres; edad media 40.4 años), con patrón tipo 1 espontáneo (74.4%) o inducido por ajmalina (25.6%). El 58.1% presentó variabilidad espontánea. El 18.6% tenía antecedente de muerte súbita familiar. El 39.5% era sintomático. El 18.6% presentó fibrilación auricular o flutter auricular. El antecedente de un paro cardiaco resucitado, muerte súbita o choque apropiado del desfibrilador automático implantable se consideró evento arrítmico maligno. Durante un seguimiento promedio de 51 meses no se registraron muertes, el 6.9% de los pacientes presentó un evento arrítmico maligno, y en su totalidad fueron choques apropiados. La tasa anual de eventos arrítmicos malignos en los pacientes con síncope fue del 1.7%, con un patrón tipo 1 espontáneo, del 2.79%, y con variabilidad espontánea, del 2.87%. No se observaron eventos arrítmicos malignos en los asintomáticos y en aquellos con un patrón persistente o tipo 1 inducido. La tasa anual de eventos con antecedente positivo o negativo de muerte súbita familiar fue del 2.94 y 1.7%, respectivamente. En presencia de fibrilación auricular, flutter auricular y fibrilación auricular/flutter auricular fue del 7.3, 15.69 y 10%, respectivamente. En ausencia de fibrilación/flutter no se observaron eventos arrítmicos malignos. Conclusión: De las variables analizadas, las que tuvieron mayor relación con la presencia de un evento arrítmico maligno fueron la presencia de fibrilación auricular (p = 0,046) y de flutter auricular (p = 0,03).

Objective: To analyze the specific risk for the variables: type 1 spontaneous pattern, type 1 induced pattern, type 1 pattern with spontaneous variability, syncope, family history of sudden death, atrial fibrillation and atrial flutter with the subsequent development of malignant arrhythmic events. Methods: Forty-three Brugada patients (90% males; mean age 40.4 years), with a type 1 spontaneous pattern (74.4%) or induced by ajmaline (25.6%) were retrospectively analyzed. Of these, 58.1% presented spontaneous variability, 18.6% had family history of sudden death, 39.5% were symptomatic, and 18.6% presented atrial fibrillation or atrial flutter. The antecedents of resuscitated cardiac arrest, sudden death or appropriate shock from implantable automatic defibrillator were considered malignant arrhythmic events. During a mean follow up of 51 months, no deaths were recorded, 6.9% of the patients presented a malignant arrhythmic event, and all of them were appropriate shocks. The annual rate of events in patients with syncope was 1.7%, with a spontaneous type 1 pattern was 2.79%, and spontaneous variability was 2.87%. No malignant arrhythmic event was observed in asymptomatic patients or in those with a persistent pattern or induced type 1 pattern. The annual rate of events with positive or negative history of family sudden death was 2.94 and 1.7%, respectively. In the presence of atrial fibrillation, atrial flutter and atrial fibrillation/atrial flutter were 7.3, 15.69 and 10%, respectively. In the absence of atrial fibrillation/atrial flutter no malignant arrhythmic events were observed. Conclusion: Of the variables analyzed, the one that was most related to a malignant arrhythmic event was the presence of atrial fibrillation (P= .046) and atrial flutter (P= .03).

Flutter auricular: Hallazgo inusual en neonatos

Objetivo general: Describir y analizar la presentación neonata de un flutter auricular. Presentamos el caso de un recién nacido que desde su primeras horas de visa cursa con taquicardia sostenida. Durante su segundo día de vida, luego de múltiples intentos fallidos de reversión con maniobras pagables o medicamentos, se hace diagnostico de flutter auricular; por lo que se le realiza cardioversión eléctrica con excelente evolución. El flutter auricular es una taquicardia supraventricular de QRS estrecho irregular, cuyo tratamientos la cardioversión eléctrica; con excelente pronóstico en la ausencia de arritmias asociadas o malformaciones cardíacas.

Objetive: Describe and analyze the neonatal presentation of an atrial flutter. This is the case of a newborn, who develops tachycardia i this first hours of life. During his second day, after many unsuccessful attempts with vagal maneuvers and drugs, diagnosis of atrial flutter was done. We performed electric cardio version with excellent results. Atrial flutter is a supraventricular tachycardia with an irregular, narrow QRS; the treatment is electrical cardio version; with excellent prognosis in the absence of arrhythmia or structural cardiac malformations.