Cicatrices mesocárdicas como sustrato de taquicardia ventricular en pacientes con tamaño y función ventricular normales / Mesocardiac scars as the substrate of ventricular tachycardia in patients with normal ventricular size and function

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Enfoque clínico de la taquicardia y el aleteo auricular desde su mecanismo: electrofisiología basada en la anatomía / Clinical approach to atrial tachycardia and atrial flutter from an understanding of the mechanisms. Electrophysiology based on anatomy

En el año 2009 se llevaron a cabo en España 2.343 procedimientos de ablación con catéter de aleteo, taquicardia macrorreentrante atípica o taquicardia auricular focal, con un crecimiento del 8% sobre el año anterior, lo que da una idea de la importancia clínica de estas arritmias. La clasificación tradicional que distingue la taquicardia auricular del aleteo auricular basándose en criterios de frecuencia y morfología de ondas ha dejado de ser relevante, en un momento en que el desarrollo de la electrofisiología clínica puede permitir una intervención curativa sobre la arritmia, basada en su mecanismo, y se hace muy necesario acercar la experiencia del laboratorio a la clínica. En esta revisión se dibuja el panorama actual de los mecanismos de taquicardias auriculares, tanto focales como reentrantes, procurando establecer lazos con los conceptos clásicos que permitan al clínico enfrentarse a los diagnósticos diferenciales y hacer las indicaciones correctas de tratamiento, incluido el estudio electrofisiológico. Algunos de los conceptos expuestos son complejos, pero creemos que es necesario apuntar la perspectiva de los métodos electrofisiológicos que permiten dibujar las bases anatómicas de las arritmias, que hoy resultan más fácilmente comprensibles gracias a la construcción de moldes anatómicos con sistemas computarizados de navegación (AU)

In 2009, 2343 catheter ablation procedures were performed in Spain for focal atrial tachycardia or atrial flutter (typical and atypical), with a yearly growth rate of 8%, indicating the clinical importance of these arrhythmias. The classic categorization of atrial tachycardia and atrial flutter based on rate and morphological criteria has become almost irrelevant at a time when clinical electrophysiology may lead to curative intervention based on a definition of the mechanism, making it necessary to bring laboratory experience closer to clinical practice. In this review we outline our present understanding of atrial tachycardia mechanisms, both focal and macroreentrant, and attempt to establish the conceptual links with classic concepts that may help the clinician to make a differential diagnosis and establish therapeutic indications, including that of an electrophysiologic study. Some of the concepts may seem complex, but we thought it important to provide an overview of the electrophysiological methods that may eventually lead to the description of the anatomic bases of the arrhythmias; currently, these are easier to understand thanks to the virtual anatomic casts built using computerized navigation systems (AU)

Arrhythmias (IV). Clinical approach to atrial tachycardia and atrial flutter from an understanding of the mechanisms. Electrophysiology based on anatomy.

In 2009, 2343 catheter ablation procedures were performed in Spain for focal atrial tachycardia or atrial flutter (typical and atypical), with a yearly growth rate of 8%, indicating the clinical importance of these arrhythmias. The classic categorization of atrial tachycardia and atrial flutter based on rate and morphological criteria has become almost irrelevant at a time when clinical electrophysiology may lead to curative intervention based on a definition of the mechanism, making it necessary to bring laboratory experience closer to clinical practice. In this review we outline our present understanding of atrial tachycardia mechanisms, both focal and macroreentrant, and attempt to establish the conceptual links with classic concepts that may help the clinician to make a differential diagnosis and establish therapeutic indications, including that of an electrophysiologic study. Some of the concepts may seem complex, but we thought it important to provide an overview of the electrophysiological methods that may eventually lead to the description of the anatomic bases of the arrhythmias; currently, these are easier to understand thanks to the virtual anatomic casts built using computerized navigation systems.

La eco-3D no ve la anatomía de la aurícula izquierda / 3-D echocardiography does not reveal left atrial anatomy

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Indicación de desfibrilador automático implantable en paciente con angina de Prinzmetal y síncopes / No disponible

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El infarto posterior existe / Posterior myocardial infarction is real

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[The superior vena cava as a site of ectopic foci in atrial fibrillation]. / La vena cava superior como inductora de fibrilación auricular de origen focal.

Radiofrequency catheter ablation of ectopic foci that trigger atrial fibrillation has been established as a curative method for patients with symptomatic paroxysmal atrial fibrillation. Although the majority of these foci are located in and around the pulmonary veins, other less common locations have been identified. Recognition that foci can lie outside the pulmonary veins is important for ensuring therapeutic success. The most frequently reported foci of ectopic activity outside the pulmonary veins are in the superior vena cava and the posterior wall of the left atrium. Here we report our experience with the ablation of ectopic foci located in the superior vena cava in patients with symptomatic paroxysmal atrial fibrillation.

¿Qué es y cómo se diagnostica la fibrilación auricular? / What exactly is atrial fibrillation and how do we diagnose it?

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La vena cava superior como inductora de fibrilación auricular de origen focal / The superior vena cava as a site of ectopic foci in atrial fibrillation

La ablación de focos auriculares precipitantes de fibrilación auricular se ha constituido como una técnica curativa para pacientes con fibrilación auricular paroxística sintomática. Aunque la mayoría de focos ha sido descrita en las venas pulmonares, se han identificado otras localizaciones que, aunque menos frecuentes, pueden ser de relevancia clínica en determinados pacientes. El reconocimiento de estas localizaciones durante un procedimiento de ablación es fundamental a la hora de planear el abordaje anatómico. La vena cava superior, junto con la pared posterior de la aurícula izquierda, suele ser la localización más frecuente de actividad ectópica fuera de las venas pulmonares. Presentamos nuestra experiencia de la ablación de focos ectópicos en la vena cava superior en pacientes con fibrilación auricular paroxística sintomática

Radiofrequency catheter ablation of ectopic foci that trigger atrial fibrillation has been established as a curative method for patients with symptomatic paroxysmal atrial fibrillation. Although the majority of these foci are located in and around the pulmonary veins, other less common locations have been identified. Recognition that foci can lie outside the pulmonary veins is important for ensuring therapeutic success. The most frequently reported foci of ectopic activity outside the pulmonary veins are in the superior vena cava and the posterior wall of the left atrium. Here we report our experience with the ablation of ectopic foci located in the superior vena cava in patients with symptomatic paroxysmal atrial fibrillation

[Atrial flutter: an update]. / Flúter auricular: perspectiva clínica actual.

Invasive electrophysiologic studies have changed the clinical outlook for patients with atrial flutter. Recognition of the reentrant circuit responsible for typical atrial flutter has led to the development of catheter ablation techniques that can prevent recurrence in >90% of cases. In addition, general understanding of atrial tachycardias has changed radically, such that ECG-based classifications are now obsolete. Atypical reentrant circuits associated with surgical scars or fibrotic areas in either atrium, which are indistinguishable from focal tachycardias on ECG, have been identified. These circuits also seem amenable to treatment by ablation. Recently, a new type of reentrant tachycardia that could be problematic in the future has emerged in patients who have undergone extensive left atrial ablation for the treatment of atrial fibrillation. These atypical circuits can be characterized using the mapping and entrainment techniques initially developed for typical flutter. In these cases, electroanatomical mapping, involving the construction of a virtual anatomical model of the atria, is extremely helpful. Despite the success of ablation, long-term prognosis is frequently overshadowed by the appearance of atrial fibrillation, which suggests that flutter and fibrillation share a common arrhythmogenic origin that is not modified by cavotricuspid isthmus ablation. In contrast with our clear electrophysiologic understanding of atrial flutter, little is known about the natural history of the condition because the literature has traditionally grouped patients with flutter and fibrillation together. Consequently, the complex relationship between the two arrhythmias has still to be clearly delineated. Primary prevention and preventing the development of atrial fibrillation after ablation remain outstanding clinical challenges.

Flúter auricular: perspectiva clínica actual / Atrial Flutter: an Update

Los estudios electrofisiológicos invasivos han cambiado la perspectiva clínica de los pacientes con flúter auricular. El conocimiento de la estructura del circuito de flúter típico ha permitido desarrollar técnicas de ablación con catéter que eliminan las recidivas en > 90% de los casos. También ha cambiado el concepto global de las taquicardias auriculares, lo que ha hecho obsoletas las clasificaciones basadas en el electrocardiograma. Se han demostrado circuitos reentrantes atípicos basados en cicatrices quirúrgicas o en zonas fibróticas en ambas aurículas, que son también asequibles a tratamiento por ablación y que en el electrocardiograma son indistinguibles de una taquicardia focal. La ablación amplia de la aurícula izquierda para el tratamiento de la fibrilación auricular está dando lugar a un nuevo tipo de taquicardias reentrantes que puede ser problemático en el futuro. Las técnicas de mapeo y encarrilamiento de los circuitos descritas inicialmente en el flúter permiten definir estos circuitos. El mapeo electroanatómico, que construye moldes anatómicos virtuales de las aurículas, es de gran ayuda en estos casos. A pesar del éxito de la ablación, el pronóstico a largo plazo se ensombrece con frecuencia por la aparición de fibrilación auricular, lo que indica que hay un sustrato arritmogénico común al flúter y la fibrilación, que la ablación del istmo cavotricuspídeo no cambia. En contraste con la clara definición electrofisiológica, hay escasa información sobre el curso clínico del flúter, ya que tradicionalmente la bibliografía se refiere a grupos de «flúter y fibrilación auricular» y las complejas relaciones entre ambas arritmias quedan aún por revelar claramente. La prevención primaria y la prevención de la aparición de fibrilación auricular tras la ablación son retos pendientes (AU)

Invasive electrophysiologic studies have changed the clinical outlook for patients with atrial flutter. Recognition of the reentrant circuit responsible for typical atrial flutter has led to the development of catheter ablation techniques that can prevent recurrence in >90% of cases. In addition, general understanding of atrial tachycardias has changed radically, such that ECG-based classifications are now obsolete. Atypical reentrant circuits associated with surgical scars or fibrotic areas in either atrium, which are indistinguishable from focal tachycardias on ECG, have been identified. These circuits also seem amenable to treatment by ablation. Recently, a new type of reentrant tachycardia that could be problematic in the future has emerged in patients who have undergone extensive left atrial ablation for the treatment of atrial fibrillation. These atypical circuits can be characterized using the mapping and entrainment techniques initially developed for typical flutter. In these cases, electroanatomical mapping, involving the construction of a virtual anatomical model of the atria, is extremely helpful. Despite the success of ablation, long-term prognosis is frequently overshadowed by the appearance of atrial fibrillation, which suggests that flutter and fibrillation share a common arrhythmogenic origin that is not modified by cavotricuspid isthmus ablation. In contrast with our clear electrophysiologic understanding of atrial flutter, little is known about the natural history of the condition because the literature has traditionally grouped patients with flutter and fibrillation together. Consequently, the complex relationship between the two arrhythmias has still to be clearly delineated. Primary prevention and preventing the development of atrial fibrillation after ablation remain outstanding clinical challenges (AU)

[Cardiac resynchronization in heart failure: well-established therapy or new approach with unanswered questions?]. / Resincronización ventricular en la insuficiencia cardíaca: ¿un método bien establecido o una línea de progreso con muchos interrogantes?

Biventricular pacing is a new development in the treatment of ventricular failure associated with intraventricular conduction delays, and the term ventricular resynchronization has been coined, implying for many authors that synchronous right and left ventricular activation and contraction are the goal of therapy. However, there is ample evidence that isolated left ventricular stimulation may be at least as efficacious as biventricular stimulation, and the mechanisms of functional improvement remain speculative. The role of mitral regurgitation and its modification with resynchronization has not been fully evaluated. Long-term prognosis, effect on mortality and predictors of a positive response are important unanswered questions. It is clear that a narrow-based QRS complex is not a good indicator of a favorable response. We need to better understand the effect of the activation sequence on left ventricular contraction dynamics, including mitral valve function, to refine the technique and indications for resynchronization therapy.

"Resincronización ventricular" en la insuficiencia cardíaca: ¿un método bien establecido o una línea de progreso con muchos interrogantes? / "Cardiac resychronization" in heart failure: well-established therapy or new approach with unanswered questions?

La estimulación biventricular ha supuesto una línea nueva de desarrollo para el tratamiento de los pacientes con insuficiencia cardíaca asociada a retrasos de la conducción intraventricular, y el término "resincronización ventricular", acuñado por muchos autores, implica que la sincronía entre la activación y contracción del ventrículo izquierdo y derecho es el objetivo de esta terapia. Sin embargo, existen amplias evidencias de que la estimulación aislada del ventrículo izquierdo puede ser, al menos,tan efectiva como la estimulación biventricular, haciendo que los mecanismos de mejoría citados sean especulativos. El papel de la insuficiencia mitral y sus cambios con la "resincronización" no han sido completamente evaluados. El pronóstico a largo plazo, el efecto en la mortalidad y los predictores de respuesta positiva son cuestiones importantes todavía no resueltas. Está bastante claro que perseguir un complejo QRS estrecho con la estimulación no es un buen indicador de una respuesta favorable,y que necesitamos comprender mejor el efecto que supone la secuencia de activación ventricular izquierda sobre la contracción, incluyendo el efecto sobre la función de la válvula mitral para, con ello, poder mejorar la técnica y las indicaciones de la terapia de "resincronización" (AU)

[Electrophysiological and clinical characterization of left atrial macroreentrant tachycardia]. / Caracterización electrofisiológica y clínica de la taquicardia macrorreentrante auricular izquierda.

BACKGROUND AND OBJECTIVE: We are reporting the characteristics of 9 patients with left atrial macroreentrant tachycardia, an arrhythmia not well studied in man. PATIENTS AND METHOD: Mean age was 60 years and 7 were men. Tachycardia was spontaneous in 6 and induced in 3. Two had no heart disease, 2 sick sinus syndrome, 3 aortic prosthesis, 2 hypertension, 1 cardiomyopathy and 1 chronic bronchitis. Simultaneous recordings from right atrial, coronary sinus and right pulmonary artery were obtained at baseline and with atrial pacing. Macroreentrant tachycardia was diagnosed when entrainment with fusion was documented. RESULTS: Cycle length was 230-440 ms (287 67). The ECG showed atypical flutter in 3 patients and P waves with flat baseline in 6. Coronary sinus activation was distal to proximal in 7. Right atrial activation was circular in 3 with previous typical flutter ablation. Entrainment from the right atrium produced long return cycles in the right atrial recordings, but equal to basal tachycardic cycle in coronary sinus recordings. Entrainment from the coronary sinus produced local return cycles equal to basal cycle in 8 and prolonged in 1. After stimulation, 4 recovered sinus rhythm, 4 went to atrial fibrillation and 1 had no change. After a follow-up of 9-19 months 5 remain in sinus rhythm treated with antiarrhythmic drugs and/or atrial pacing. CONCLUSIONS: Left atrial macroreentrant tachycardia is associated with organic heart disease. The ECG most frequent pattern tends to show P waves with flat baseline at a relatively slow rate. Most circuits turn clockwise in anterior view. Atrial stimulation is not very effective for cardioversion to sinus rhythm. The prognosis of long term rhythm is uncertain.