Enrique Rodríguez Font

Atrial Fibrillation Is Associated With Increased Spontaneous Calcium Release From the Sarcoplasmic Reticulum in Human Atrial Myocytes

Background—Spontaneous Ca2+ release from the sarcoplasmic reticulum (SR) can generate afterdepolarizations, and these have the potential to initiate arrhythmias. Therefore, an association may exist between spontaneous SR Ca2+ release and initiation of atrial fibrillation (AF), but this has not yet been reported. Methods and Results—Spontaneous Ca2+ release from the SR, manifested as Ca2+ sparks and Ca2+ waves, was recorded with confocal microscopy in atrial myocytes isolated from patients with and those without AF. In addition, the spontaneous inward current associated with Ca2+ waves was measured with the use of the perforated patch-clamp technique. The Ca2+ spark frequency was higher in 8 patients with AF than in 16 patients without (6.0±1.2 versus 2.8±0.8 sparks/mm per second, P<0.05). Similarly, the spontaneous Ca2+ wave frequency was greater in patients with AF (2.8±0.5 versus 1.1±0.3 waves/mm per second, P<0.01). The spontaneous inward current frequency was also higher in 10 patients with AF than in 13 patients without this arrhythmia (0.101±0.028 versus 0.031±0.007 per second, P<0.05, at a clamped potential of −80 mV). In contrast, both the Ca2+ released from the SR and the Na+-Ca2+ exchange rate induced by a rapid caffeine application were comparable in patients with and without AF. Conclusions—The observed increase in spontaneous Ca2+ release in patients with AF probably is due to an upregulation of the SR Ca2+ release channel activity, which may contribute to the development of AF.

Spanish Registry of Catheter Ablation. Third Official Report of the Working Group on Electrophysiology and Arrhythmias of the Spanish Society of Cardiology (2003)

INTRODUCTION The results of the Third Spanish Catheter Ablation Registry, developed by the Working Group on Electrophysiology and Arrhythmias, are presented for the third consecutive year (2003). MATERIAL AND METHOD In contrast to previous years, data were collected in two different ways at the discretion of the participating center. Retrospective were obtained with a standard questionnaire, as in previous years. Prospective data were obtained from a database of records completed after each ablation was performed. Results and complications are presented according to different arrhythmic substrates. RESULTS Thirty-nine centers participated in the registry (25 supplied prospective data and 14 retrospective data), representing more than 80% of all electrophysiological laboratories in Spain. A total number of 4354 ablations were recorded (111 procedures per center, 2723 from the prospective registry and 1631 from the retrospective one). The substrate most frequently treated was AV nodal reentry tachycardia (31.6%, 98% success), followed by accessory pathways (26%, 89% success) and atrial macro-reentry tachycardia (23%, 90% success). The incidence of complications was 1.7% and mortality was 0.11%. With the prospective registry we obtained more comprehensive information individualized for each procedure (age, sex, underlying cardiomyopathy, anticoagulation, sedation, type of catheter, etc.). CONCLUSIONS The high rate of participation in the registry and the consistency of the results with previous years help to consolidate the registry as a reference for the rest of the scientific community. The results from the prospective registry showed better-quality information and more detailed reporting of results and complications.

Registro Español de Ablación con Catéter. III Informe Oficial de la Sección de Electrofisiología y Arritmias de la Sociedad Española de Cardiología (2003)

Introduccion Por tercer ano consecutivo se presentan los resultados del Registro Nacional de Ablacion con Cateter, elaborado por la Seccion de Electrofisiologia y Arritmias, con datos del ano 2003. Material y metodo A diferencia de anos anteriores, la recogida de datos se realizo a traves de 2 vias y cada centro eligio libremente entre ellas. Una via fue retrospectiva, a traves de un cuestionario estandarizado. La otra via fue prospectiva, a traves de una base de datos que habia que rellenar tras cada ablacion. Se presentan los resultados y las complicaciones por sustrato arritmico tratado. Resultados Participaron en el registro 39 centros (25 de forma prospectiva y 14 retrospectiva), lo que supone una participacion de mas del 80% de centros que realizan ablacion en Espana. Se registraron un total de 4.354 ablaciones (111 ablaciones/centro, 2.723 del registro prospectivo y 1.631 del retrospectivo), con un exito por procedimiento del 91%. El sustrato tratado con mas frecuencia fue la taquicardia intranodal (31,6%, con un 98% de exito), seguido de las vias accesorias (26%, con un 89% de exito) y la macrorreentrada auricular (23%, con un 90% de exito). La incidencia de complicaciones fue del 1,7% y la mortalidad periprocedimiento, del 0,11%. A traves del registro prospectivo se pudo obtener amplia informacion individualizada de cada procedimiento (edad, sexo, cardiopatia, anticoagulacion, sedacion, tipo de cateter, etc.). Conclusiones La elevada participacion y la consistencia de los resultados con los de anos previos ayudan a consolidar este Registro como referencia para el resto de la comunidad cientifica. Los resultados del registro prospectivo ofrecen una informacion de mejor calidad y mas detallada en sus resultados y complicaciones.

Pulmonary vein isolation in cases of difficult catheter placement: A new pacing maneuver to demonstrate complete isolation of the veins

BACKGROUND Pulmonary vein electrical isolation is the main goal of atrial fibrillation ablation. To ensure electrical isolation of the pulmonary veins, entrance and exit block should be demonstrated. However, this is sometimes challenging due to the complex anatomy of the pulmonary vein area and the anatomical variations that may preclude the correct position of the commonly used circular multielectrode catheter inside the veins. OBJECTIVE To describe a new pacing maneuver useful to demonstrate complete isolation of ipsilateral veins in cases of difficult catheter placement. METHODS Three representative cases illustrate the usefulness of the maneuver either at the right or left pulmonary veins. RESULTS After the circumferential ablation of ipsilateral veins, the circular catheter is positioned in one vein and the ablation catheter in the other ipsilateral vein. When local capture in one vein can be demonstrated while pacing from the other vein and no conduction to the atria is observed, isolation of both veins can be assured. CONCLUSION This novel maneuver might be of help in assessing complete isolation of the pulmonary veins in cases of difficult circular catheter placement.

Flúter auricular típico en corazón trasplantado

El flúter auricular es la arritmia más frecuente en los pacientes sometidos a trasplante cardíaco ortotópico. Se presenta un caso representativo de un flúter auricular típico con rotación antihoraria alrededor del anillo tricuspídeo en una paciente sometida a trasplante cardíaco ortotópico 13 años antes. El mapa de activación de la arritmia (fig. 1) muestra el encuentro entre las zonas más precoces y más tardías característico de las macrorreentradas. Se representó como «escara» (en gris) la zona correspondiente a la aurícula receptora, que presentaba una taquisistolia auricular con longitud de ciclo ligeramente más lenta que la del flúter y sin relación con IMÁGENES EN CARDIOLOGÍA

Spanish Catheter Ablation Registry. Fourth Official Report of the Spanish Society of Cardiology Working Group on Electrophysiology and Arrhythmias (2004)

Introduction This article details the findings (i.e., success and complication rates) of the 2004 Spanish Catheter Ablation Registry, which was established by the Spanish Society of Cardiology Working Group on Electrophysiology and Arrhythmias. This is the fourth consecutive annual report. Material and method Similar to last year, data were collected in two ways: retrospectively using a standard questionnaire, and prospectively using a central database containing details of each ablation procedure. Each center was asked to participate by selecting one of these methods. Results Thirty-six centers contributed voluntarily to the registry. Overall, 4147 ablation procedures were reported, giving a mean of 115 [66] procedures per center. The three main conditions treated were AV node reentry tachycardia (32%), the presence of accessory pathways (25%), and common atrial flutter (23%). Success rates were 98%, 89%, and 91%, respectively. The overall success rate was 90%, with a major complication rate of 1.4% and a mortality rate of 0.07%. Conclusions Although the participation rate was slightly lower than in previous years, the comparability of data collected on a substantial number of ablation procedures (more than 4000) with earlier registry data confirm the validity and consistency of the register.

Identification of the critical isthmus of a reentrant ventricular tachycardia at a glance

A 61-year-old male with prior inferior myocardial infarction was referred for catheter ablation of a monomorphic ventricular tachycardia (VT). His left ventricular ejection fraction was 45% and a cardiac magnetic resonance showed late gadolinium enhancement at the inferobasal left ventricle. Detailed endocardialmapping of the left ventricle was performed during sinus rhythm, using the multielectrode catheter Pentaray and the CARTO 3 mapping system (Biosense Webster, Inc., Diamond Bar, CA, USA). A low-voltage area (<1.5 mV) was identified at the inferobasal left ventricle. During VT, tiny diastolic potentials were recorded along the entirely VT cycle length at the septal border of the scar (Figure 1A and B). Following the sequence of activation of the diastolic potentials recorded by the multipolar catheter, we were able to reconstruct the activation along the critical isthmus of the VT that was confirmed by entrainment maneuvers. Interestingly, spontaneous termination of the VT showed that most of the diastolic potentials recorded during VT were canceled by the ventricular electrogram during sinus rhythm at the same location, and therefore, difficult to identify by voltage criteria. This emphasizes how the configuration of the recorded electrograms is influenced by the wave front activation and suggests that at least part or the isthmuswas functional. Pacing during sinus rhythm from different poles of the Pentaray catheter identified nonexcitable tissue in close proximity to the critical isthmus, leading to a better delimitation of the substrate involved in the VT circuit. Radiofrequency applications across the isthmus terminatedVTand rendered the tachycardia not inducible. The case illustrates the potential of the simultaneous recording from multiple small electrodes in improving our understanding of the VT substrate.

Registro Español de Ablación con Catéter. III Informe Oficial (2003)

Se presentan los resultados del Registro Nacional de Ablacion con Cateter, elaborado por la Seccion de Electrofisiologia y Arritmias, con datos del ano 2003. A diferencia de anos anteriores, la recogida de datos se realizo a traves de 2 vias y cada centro eligio libremente entre ellas. Una via fue retrospectiva, a traves de un cuestionario estandarizado. La otra via fue prospectiva, a traves de una base de datos que habia que rellenar tras cada ablacion. Se presentan los resultados y las complicaciones por sustrato arritmico tratado. Participaron en el registro 39 centros (25 de forma prospectiva y 14 retrospectiva), lo que supone una participacion de mas del 80% de centros que realizan ablacion en Espana. Se registraron un total de 4.354 ablaciones (111 ablaciones/centro, 2.723 del registro prospectivo y 1.631 del retrospectivo), con un exito por procedimiento del 91%. El sustrato tratado con mas frecuencia fue la taquicardia intranodal (31,6%, con un 98% de exito), seguido de las vias accesorias (26%, con un 89% de exito) y la macrorreentrada auricular (23%, con un 90% de exito). La incidencia de complicaciones fue del 1,7% y la mortalidad periprocedimiento, del 0,11%. A traves del registro prospectivo se pudo obtener amplia informacion individualizada de cada procedimiento (edad, sexo, cardiopatia, anticoagulacion, sedacion, tipo de cateter, etc.). La elevada participacion y la consistencia de los resultados con los de anos previos ayudan a consolidar este registro como referencia para el resto de la comunidad cientifica. Los resultados del registro prospectivo ofrecen una informacion de mejor calidad y mas detallada en sus resultados y complicaciones.

Imagen de seudocaptura por microdesplazamiento del electrodo en un marcapasos VDD

Los nuevos marcapasos secuenciales auriculoventriculares(AV) han mejorado la individualizacionen el modo de estimulacion para cada paciente. Lacomplejidad de los sistemas hace en ocasiones dificildetectar algunas malfunciones. En el caso clinicoque presentamos se expone como un fallo decaptura por microdesplazamiento del electrodopuede pasar desapercibido en un control sencillode marcapasos, al unirse varios factores como presentarconduccion AV normal en ese momento, laconcordancia entre la espicula y el QRS conducidoy la similar morfologia entre el complejo QRS conducidoy el estimulado.