Catheter Ablation in Neonate with Heart Failure Due to Incessant Atrioventricular Reentrant Tachycardia

Abstract The atrioventricular (AV) reentrant tachycardia (AVRT) is the most common cause of supraventricular tachycardia (SVT) in the young pediatric population. Some newborns might present with congestive heart failure and require interventional treatment. Catheter ablation in small infants (<6 months and <5 kg) is still poorly performed and controversial due to high complications rate in this group of patients.1 We report a case of a 28 days old infant (3,5 kg) with a drug-refractory left accessory pathway mediated tachycardia and severe hemodynamic compromise, who underwent catheter ablation. Radiofrequency ablation should be part of the therapeutic arsenal in a context of drug-resistant supraventricular tachycardia with hemodynamic compromise, despite the greater risks of complications in this special population.

Taquicardia por reentrada nodal recurrente en paciente con transposición congénita corregida de grandes vasos. Utilización de mapeo no fluoroscópico / Use of non-fluoroscopic mapping in recurrent atrioventricular nodal reentrant tachycardia in a patient with corrected transposition of the great arteries

La complejidad anatómica y la variabilidad en el sistema de conducción en la transposición congénita corregida de los grandes vasos plantean intervenciones con el uso de recursos tecnológicos que faciliten un desenlace favorable. Describimos un caso de ablación de taquicardia por reentrada intranodal en donde el mapeo no fluoroscópico facilitó una intervención compleja.

The anatomy in congenital corrected transposition of the great arteries is complex and the conduction system may experience large degrees of variation. Invasive procedures should be done with the use of the highest possible technological sources to warrant success. We describe here, a patient with recurrent atrioventricular node reentry tachycardia where non-fluoroscopic navigation system helped in a complex ablation.

Catheter cryoablation of atrio-ventricular nodal reentrant tachycardia. A clinical review / Crioablación con catéter de la taquicardia por reentrada intranodal. Una revisión clínica

Cryoablation is a new method in interventional cardiac electrophysiology for percutaneous catheter ablation of cardiac arrhythmias. Cryothermal mapping enables the functional assessment of a particular site before permanent ablation. In this way, the targeted tissue may be confirmed as safe for ablation. This is useful in high-risk ablation, for example, next to the His bundle or the compact AV node. In the last decade, several studies have been addressed to AV-nodal reentry tachycardia (AVNRT) cryoablation. Current experiences indicate that cryoablation for AV-nodal reentry tachycardia is effective and safe. However, its wide use seems to be somewhat limited by a slightly lower efficacy when compared to radiofrequency. Further studies evaluating long-term success of cryothermal ablation versus radiofrequency are warranted. However, for high-risk ablations, cryoenergy is very helpful and should be systematically used. This article is a review of acute and long-term effects of cryoablation in patients suffering of AV-nodal reentry tachycardia episodes.

La crioablación es un nuevo método en la electrofisiología cardiaca intervensionista para la ablación percutánea de las arritmias cardiacas. El mapeo criotérmico permite la evaluación funcional de un sitio en particular antes de la ablación permanente; de esta manera, el tejido blanco puede confirmarse como seguro para el procedimiento. Esto es útil en la ablación de alto riesgo, por ejemplo, cerca del haz de His o del nodo AV compacto. En la última década, varios estudios se han orientado a la crioablación para la taquicardia de reentrada del nodo AV (TRNAV). Las experiencias actuales indican que la crioablación de la taquicardia de reentrada del nodo AV es efectiva y segura. Sin embargo, la apertura para ampliar su uso está parcialmente limitada por su eficacia ligeramente menor al compararla con el empleo de la radiofrecuencia. Se justifican ensayos clínicos futuros con objeto de evaluar el éxito a largo plazo de la ablación criotérmica en comparación con la radiofrecuencia. Para las ablaciones de alto riesgo, la crioenergía es muy útil y debería ser usada sistemáticamente. Este artículo consiste en una revisión sobre los efectos inmediatos y a largo plazo de la crioablación en pacientes que presentan episodios de taquicardia por reentrada del nodo AV.

Prevention of atrioventricular block during radiofrequency ablation by pace mapping of Koch's triangle

Complete atrioventricular block [AV block] is a serious complication of slow pathway ablation therapy in the treatment of atrioventricular nodal re-entrant tachycardia [AVNRT]. The present study was aimed at determining whether the electroanatomical pace mapping of Koch's triangle could significantly improve the safety, efficiency, and efficacy of selective slow pathway ablation in the treatment of AVNRT. A total number of 124 patients were selected to be studied consecutively for radiofrequency [RF] ablation therapy in the treatment of AVNRT. The subjects were divided into two groups: one, designated Group 1, to serve as the control group, and the other, designated Group 2, to serve as the study group. Conventional fluoroscopic slow pathway ablation was performed on the Group 1 subjects [n=66], with the Group 2 subjects receiving slow pathway ablation therapy guided by pace mapping of Koch's triangle. The slow pathway ablation in Group 2 [n=58] was performed with regard to the pace mapping data obtained on the basis of the St-H interval in the anteroseptal [AS], midseptal [MS], and posteroseptal [PS] regions of Koch's triangle. The anterograde fast pathway [AFP] location was determined based on the shortest St-H interval obtained by stimulating the anteroseptal [AS], midseptal [MS], and posteroseptal [PS] aspects of Koch's triangle. In the Group 2 subjects, AFP location was AS in 50 [86.2%] of the cases, MS in 7 [12%] of the cases, and PS in 1 case [1.7%]. One patient with posteroseptal AFP was administered retrograde fast pathway ablation therapy. One patient in the control group [Group 1], representing 1.5% of the group, developed persistent AV block in the course of the treatment, but none of the subjects in the study group [Group 2] developed any complications. It was concluded that an atypical fast pathway location is conducive to the development of atrioventricular block in the ablation therapy in AVNRT, with pace mapping of Koch's triangle having the capacity to eliminate the risk of any such complication developing. It follows that it helps to identify the AFP location before ablation therapy is administered in AVNRT, thereby improving the safety of the treatment

Contribuição da análise eletrofisiológica e anatômica do circuito atípico da taquicardia atrioventricular nodal / Contribution of the electrophysiological and anatomical analysis of the atypical atrioventricular nodal tachycardia circuit

OBJETIVOS: Analisar a condução retrógrada durante os episódios de ritmo juncional ectópico acelerado (JET) e avaliar a existência da relação entre a presença de um bloqueio retrógrado e o risco de desenvolvimento de bloqueio atrioventricular (BAV) durante os procedimentos de ablação por radiofreqüência de pacientes portadores de taquicardia atrioventricular nodal (TAVN). MÉTODOS: Foram 145 pacientes portadores de TAVN, de ambos os sexos, com 16 a 84 anos submetidos à ablação com cateter de radiofreqüência na região póstero-septal do átrio direito. Critérios avaliados: localização anatômica e comportamento eletrofisiológico da condução retrógrada durante TAVN (definindo a taquicardia como típica ou atípica) e monitorização da condução retrógrada durante o JET para eventos de risco para BAV. RESULTADOS: Dos 145 pacientes estudados, 132 (91 por cento) preencheram critérios eletrofisiológicos e anatômicos da forma típica da TAVN e 13 (9 por cento), da atípica. Durante a ablação, 5,3 por cento do grupo das típicas e 30,8 por cento das atípicas apresentaram eventos de risco para BAV. Complicações após ablação foram um episódio de BAV total e outro de BAV de primeiro grau nas típicas e um de BAV de primeiro grau nas atípicas. Os três episódios foram precedidos de eventos de risco que resultaram em uma injúria nodal após procedimento. CONCLUSÃO: Portadores de TAVN atípica apresentaram porcentualmente mais eventos preditores de risco para BAV do que os da típica (p = 0,021), sendo fundamental a observação criteriosa da condução retrógrada durante o JET, afim de se evitar permanente da condução nodal, como o BAVT, após o procedimento ablativo.

OBJECTIVES: To analyze retrograde conduction during junctional ectopic tachycardia (JET) episodes and investigate the existence of a relationship between the presence of a retrograde block and the risk of atrioventricular block (AVB) development during radiofrequency ablation procedures in patients with nodal atrioventricular tachycardia (NAVT). METHODS: 145 male and female patients aged 16-84 years, with NAVT who had undergone radiofrequency catheter ablation in the posteroseptal region of the right atrium were studied. Evaluation criteria were anatomical location and electrophysiological behavior of retrograde conduction during NAVT, in order to understand the nodal reentrant circuit (classifying the tachycardia as typical or atypical), and monitoring of retrograde conduction during JET episodes for risk-predicting AVB events. RESULTS: Of the 145 patients studied, 132 (91 percent) met electrophysiological and anatomical criteria of the typical form of NAVT, and 13 (9 percent) of atypical form. During the ablation, 5.3 percent with the typical form and 30.8 percent of the atypical form presented risk events for AVB. After the ablation, complications were a total AVB episode in one patient and a first-degree AVB episode in another in the typical group, and one first-degree AVB in the atypical group. All three episodes were preceded by risk events and resulted in permanent nodal injury. CONCLUSION: Patients with atypical NAVT presented higher percentages of risk events for atrioventricular block than did patients with the typical form (p=0.021).A careful observation of retrograde conduction during JET episodes is vital in order to avoid permanent damage in AV nodal conduction, such as TAVB, after the ablation procedure.

Long-term results of radiofrequency ablation of slow pathway in patients with atrioventricular nodal reentrant tachycardia: single-center experience.

BACKGROUND: This study sought to evaluate the long-term recurrence rate of atrioventricular nodal reentrant tachycardia (AVNRT) after radiofrequency catheter ablation. The clinical and electrophysiological features of patients with AVNRT and their immediate outcomes after undergoing slow pathway ablation/modification were also studied. METHODS AND RESULTS: The study included 264 consecutive patients with AVNRT (mean age 46 -/+ 15 years, 143 women, 121 men) who underwent slow pathway ablation/modification using a combined electrophysiological and anatomical approach. The primary endpoint of ablation procedure was non- inducibility of the arrhythmia. The primary endpoint of the study was the recurrence of AVNRT on follow-up. Acute success was achieved in 262 (99.6%) patients. Complication rate of the ablation procedure was 2.6% and the average fluoroscopy time was 18.3 -/+ 11 minutes. The patients were followed up for a mean duration of 20 -/+ 9 months during which there was only one case of recurrence. CONCLUSION: Radiofrequency ablation or modification of slow pathway is highly effective in the treatment of AVNRT. The technique has a high initial success rate and a low complication rate. The recurrence rates are extremely low (0.3%) on long-term follow-up.

Ablación transquirúrgica de vía accesoria atrioventricular en anomalía de Ebstein / Surgical radioerequency catheter ablation of accessory pathways in Ebstein's anomaly

Fueron estudiados 13 pacientes con anomalía de Ebstein con taquicardia por reentrada atrioventricular y al menos una vía accesoria. En 7 pacientes (53.8%) existía una vía accesoria y en 6 pacientes (46.1%) vías múltiples. En 5 pacientes (38.4%) se encontró vía accesoria tipo Mahaim. Un total de 22 vías accesorias fueron identificadas de las cuales 2 (9%) eran ocultas. El 100% se localizaron en el anillo tricuspídeo. Los sitios más frecuentes de ubicación fueron: región lateral derecha con 11 (50%) y postero-septal derecha con 5 (22.7%). Diez pacientes recibieron tratamiento mediante ablación con radiofrecuencia vía transquirúrgica y tres mediante sección quirúrgica. Se obtuvo un éxito de 100%. No se presentaron complicaciones durante los procedimientos. Conclusión: La ablación transquirúrgica de vías accesorias atrioventriculares en pacientes con anomalía de Ebstein es un procedimiento seguro y eficaz.

Thirteen patients with Ebstein anomaly and atrioventricular reentrant tachycardia and at least one accessory pathway were included in this study. One accessory pathway in 7 (53.8%) patients and multiple accessory pathways in 6 (46.1%) were found. Mahaim accessory pathway was observed in 5 (38.4%) patients. A total of 22 accessory pathways was found, 2 (9%) were concealed. In all (100%), the accessory pathways were located in the tricuspid ring. The most frequent regions were right lateral free wall with 11 (50%) and 5 right posteroseptal (22.7%). Ten patients underwent surgical radiofrequency catheter ablation and three subjected to surgical section. We obtained success in 100%. No complications were observed during the procedures. In conclusion, surgical ablation therapy in patients with accessory pathways and Ebstein's anomaly is safe and effective.

Mapeo electroanatómico 3D y ablación percutánea transtorácica de taquicardia auricular en pacientes post cirugía de Fontan / Electro anatomic 3-D mapping and percutaneous transthoracic ablation of atrial tachycardia after Fontan surgery

Introducción: La incidencia de taquicardias auriculares (TA) luego de la operación de Fontan es alta. El acceso a la aurícula pulmonar (AuP) requiere de una punción transeptal o acceso aórtico retrógrado. Se presentan resultados iniciales con una técnica percutánea que permite el acceso a la AuP para mapeo y ablación por radiofrecuencia (ARF). Métodos: Seis EEF con mapeo 3D electroanatómico (CARTO) y ARF se efectuaron en 5 pacientes (1.2 a 17 años). Todos tenían un Fontan (túnel lateral) y TA. Vía transtoráxica se posicionó en la AuP un catéter Navistar para mapeo, estimulación y ARF. Se indujo TA con estimulación programada e isoproterenol. La secuencia de activación, áreas de bloqueo eléctrico y anatómico, y la ubicación del electrograma de His fueron definidas con mapeo 3D electroanatómico. Las zonas de interés fueron estudiadas con técnicas de “entrainment”. Luego de la ARF, el éxito se definió como la imposibilidad de reinducir TA. Resultados: Se encontró taquicardia por reentrada auricular en 5 casos y taquicardia ectópica en uno. La ARF fue exitosa en todos ellos. Hubo 1 pneumotórax y hemotórax en dos casos. En un paciente se observó recurrencia de la TA a los 3 meses, que requirió una segunda ARF, sin nueva recidiva. Ningún paciente esta recibiendo tratamiento antiarrítmico. Resumen: El acceso transtorácico percutáneo a la AuP parece apropiado para mapear y tratar las taquicardias auriculares en pacientes con cirugía de Fontan.

Seguimiento a largo plazo en 413 pacientes con vía accesoria atrioventricular sometidos a ablación con radiofrecuencia

Objetivo: se analizan los resultados clínicos y el seguimiento a largo plazo de los pacientes que fueron sometidos a ablación endocárdica mediante radiofrecuencia para el tratamiento de la taquicardia paroxística supraventricular por vía accesoria atrioventricular. Material y métodos: se incluyeron 413 pacientes a quienes se les realizó ablación con radiofrecuencia de vías accesorias atrioventricular de abril de 1992 a diciembre de 1995. Resultados: de los 413 pacientes seleccionados, 234 (57%) eran hombres y 179 (43%) eran mujeres, con edad promedio de 31.3 ± 16.3 años (límites 2 a 69 años). Se localizó un total de 437 vías accesorias atrioventriculares, 389 (93)% eran únicas y en 24 enfermos estuvieron presentes dos vías accesorias. La ablación tuvo éxito inmediato en 381 vías atrioventriculares (87%), durante el seguimiento promedio de siete años, se observó recurrencia de 51 vías atrioventriculares (13%), de estas 41 (80%) recurrieron en los primeros tres meses. A cincuenta y seis pacientes se les realizó una segunda sesión de ablación, con éxito de 35 (62.5%) y nueva recurrencia en 2 (5.7%). Son 365 vías accesorias (83.5) que permanecen sin recurrencia de taquicardia o preexcitación. Conclusiones: durante el seguimiento, los efectos de la ablación exitosa con RF se preservan en el tiempo. La taquicardia identificada en recurrencia siempre correspondió al mecanismo de reentrada a través de la vía accesoria.

Objective: the aim of this study was shown clinical characteristics and follow-up of patients with atrioventricular reentrant tachycardia (AVRT) who underwent radiofrequency catheter ablation (RCA) therapy. Material and Methods: from April 1992 to December 1995, 413 patients with AVRT underwent RCA therapy. Results: two hundred thirty four men (57%) and one hundred seventy nine women (43%) aged 31.3 ± 16-3 years were studied. 437 single accessory pathways were found; 24 had multiple accessory pathways. Ablation therapy was successful in 381 accessory pathways. During follow-up of 7 years, AVRT recurred in 51 patients (13%) and in 80% this occurred within the first 3 months after the procedure. 56 patients underwent a second RCA therapy with success in 35 patients (83.5); two reoccurred (5.7%); 365 accessory pathways (83.5) remained without evidence of preexcitation AVRT. Conclusions: during follow-up, these patients with successful ablation therapy remained without symptoms. In patients who underwent a second RCA therapy, atrioventricular reentrant mechanism was always present.

Taquicardia por reentrada nodal atrioventricular: Ablación con radiofrecuencia / Atrioventricular nodal reentrant tachycardia: radiofrequency ablation

La taquicardia por reentrada nodal atrioventricular, es una de las causas más frecuentes de taquicardia supraventricular. Es generalmente una arritmia benigna y usualmente no está asociado a cardiopatía estructural, se presenta más frecuentemente en mujeres de media edad, pero no es infrecuente encontrarlo en personas jóvenes y en ancianos. El desarrollo de la ablación con radiofrecuencia a través de un catéter facilita la cura definitiva de la arritmia y permite una mejor compresión del sustrato anatómico electrofisiológico.

Atrioventricular nodal reentrant tachycardia is the most frequent regular supraventricular tachycardia. It is generally a benign arrhythmia and usually it is no associated with heart disease. It is more often seen in middle-aged women but it is no infrequent in younger and older patients. The development of radiofrequency with catheter ablation has provided the possibility to definitely cure the arrhythmia and moreover permit a better comprehension of the underlying electrophysiologic and anatomic substrate. (Arch Cardiol Mex 2003; 73:143-154).

Catheter ablation of left free wall accessory pathway in a patient with inferior vena cava interruption.

Access to the right side of the heart for diagnostic and interventional procedures is usually obtained via the femoral vein and inferior vena cava. Anatomic variations or obstruction of the inferior vena cava can make this access difficult. In such cases, alternative routes to the right side of the heart such as the azygos vein and the superior vena cava can be used.

Relaçäo entre a persistência da conduçäo / Relation between the persistence of AV conduction over the slow pathway after AVRNT radiofrequency ablation and its recurrences

Objetivo - Verificar se a persistência de salto nodal relaciona-se à taxa de recorrência de taquicardia por reentrada nodal (TRN) após ablação com radiofreqüência (RF) da via lenta do nó atrioventricular. Métodos - Num seguimento de 20+12 meses, foi analisada a recorrência de TRN em 126 pacientes consecutivos submetidos a ablação com RF da via lenta nodal. O critério de interrupção do procedimento foi a não reindução da TRN, após estimulação atrial programada, com e sem isoproterenol intravenoso. Ao final do procedimento, 98 pacientes não apresentavam salto nodal, e em 28 persistia o salto nodal e/ou o eco atrial. Resultados - Houve recorrência clínica de TRN em 15 (11 por cento) pacientes: 9 no grupo sem salto nodal e/ou eco atrial e em 6 do grupo que persistiu com salto e/ou eco atrial. A recorrência tendeu a ser maior no 2§ grupo (9 por cento vs 21 por cento), mas não houve significância estatistica entre os resultados (p=0,09). Conclusão - Desde que a TRN não passa ser induzida após a infusão de isoproterenol, a recorrência espontânea da arritmia após a ablação por RF da via lenta nodal não é diferente entre pacientes que persistem ou não com salto nodal e/ou eco atrial.

Ablación con radiofrecuencia en el tratamiento de las arritmias supraventriculares en pediatría. Experiencia en 203 pacientes consecytivos / Radiofrequency ablation in the treatment of supraventricular arbhythmias in pediatric patients. Experience with 203 consecutive patients

Informamos los resultados de la ablación con radiofrecuencia en 203 pacientes menores de 18 años con taquiarritmias supraventriculares tratadas en el Departamento de Electrofisiología del Instituto Nacional de Cardiología "Ignacio Chávez" entre abril de 1992 y junio de 1997. La taquicardia fue causada por una vía accesoria en 181 pacientes (89.1 por ciento) con un total de 187 vías accesorias, por reentrada intranodal en 18 casos (8.8 por ciento) y flutter atrial en 4 pacientes (1.9 por ciento). El procedimiento tuvo éxito en los pacientes con vías accesorias en 171 casos (91.4 por ciento), 23 pacientes tuvieron recurrencias (12.2 por ciento). La ablación de la reentrada intranodal tuvo éxito en 18 casos: con ablación selectiva de la vía lenta en 17 y de la vía rápida en un paciente; en 3 pacientes recurrió la arritmia (16.6 por ciento. En los casos de flutter atrial, la ablación tuvo éxito en los 4 pacientes en quienes se realizó con una sola recurrencia (25 por ciento). En el total de la serie, la ablación fue exitosa en 193 casos (95 por ciento) con recurrencias en 27 casos (13.3 por ciento). Hubo complicaciones sólo en 5 pacientes (2.4 por ciento). Se concluye que la ablación de vías accesorias con radiofrecuencia es un procedimiento eficaz y seguro para suprimir las arritmias supraventriculares en niños

Ablación por catéter con radiofrecuencia en la taquicardia por reentrada nodal en pacientes con PR largo: reporte de un caso / Radiofrequency catheter ablation for nodal reentry tachycardia in patients with long PR

La taquicardia por reentrada nodal es la más común de las taquicardias supraventriculares y su tratamiento de elección es la ablación por catéter con radiofrecuencia. Esta se dirige habitualmente a eliminar la vía nodal lenta, procedimiento igualmente eficaz pero considerado más seguro que la ablación de la vía rápida. Existen situaciones clínicas sin embargo, donde puede existir indicación de realizar la ablación de la vía rápida. Presentamos el caso de un paciente con intervalo PR prolongado y con taquicardia supraventricular por reentrada nodal prácticamente incesante en el cual se realizó mapeo y ablación de la vía rápida

Radiofrequency catheter ablation for AV nodal reentrant tachycardias (AVNRT).

Radiofrequency (RF) catheter ablation is the curative treatment of choice for atrioventricular (AV) nodal reentrant tachycardia (AVNRT). Analogous to the development of surgical techniques, catheter ablation has evolved from AV nodal ablation to selective "fast" and "slow" pathway ablation. "Slow" ablation is now the method of choice because of the lower incidence of associated AV block. Though slow pathway ablation can be achieved with equal success using either the anatomic or the electrogram-guided approach, fewer applications of RF energy are required for the potential-guided technique.

Fulguración con radiofrecuencia de la vía nodal lenta: experiencia en 30 casos consecutivos / Radiofrequency fulguration of the slow nodal pathway: experience in 30 consecutives cases

Atrioventricular nodal reentry tachycardia (AVNRT) is one of the most mechanisms of paroxysmal supraventricular tachycardia. In these patients tachycardia is maintained due to anterograde conduction through a slow pathway and retrograde conduction to the atrium via a fast pathway. We present here our experience in ablation of the slow pathway. Since January 1993, 30 consecutive patients with AVNRT underwent attempted catheter ablation of the slow pathway. Mean age was 37ñ3.7 years. All patients had symptomatic tachycardia and six had history of syncope. Electrophysiological studies revealed AVNRT in all patients, in addition, 2 patients had a left accesory pathway. Slow pathway ablation was performed with Mansfield 7 F catheter, guided by both fluoroscopic positioning and endocardial signals. A mean of 13 burst were applied. In the 30 patients conduction though the slow pathway was interrupted and thus tachycardia was no longer inductible. Retrograde conduction post ablation was evaluated in 17 of the 30 patients, significant changes were observed in three of them. One patient developed second degree AV block and a permanent pacemaker was implanted. Another patient had recurrence of tachycardia three months post ablation. After a second attempt she is arrhythmia free. Patients have been followed for a mean of 15.7ñ2.5 months and are asymptomatic in the absence of antiarrhythmic therapy

Primer año del funcionamiento del Centro Nacional de Arritmias: resultados de la ablación con radiofrecuencia para el manejo de taquiarritmias / First year of functioning of the Nacional Arrhythmia Center: results in radiofrequency ablation for tachyarrhythmia therapy

Se presentan los resultados de los primeros pacientes tratados con radiofrecuencia en el Centro Nacional de Arritmias. Los resultados obtenidos son comparables a los reportes de las más grandes series norteamericanas y europeas. Por ser un centro de referencia, la mayor parte de estos pacientes son de alta complejidad y se incluyen incluso 4 enfermos tratados sin éxito en otro centro y que fueron exitosamente tratados en nuestro hospital. De esta forma, la ablación con radiofrecuencia se presenta como una excelente terapia curativa para la TPSV y TVI refractarias. Su rol en el flutter y taquicardia auricular debe definirse mejor con una mayor casuística, y su utilidad parece ser limitada en la TV secundaria a daño estructural cardíaco. Igualmente, en enfermos con taquiarritmias supraventriculares con alta frecuencia ventricular refractarios a drogas la inducción de BAV completo con RF y modulación de la frecuencia ventricular con un MP es una muy buena alternativa terapéutica

Use of a 64 channel computerized cardiac mapping system in arrhythmia surgery

A multipoint and computerized intraoperative mapping system has been known to be of value in improving the results of surgery for cardiac arrhythmia. It shows great potential as a new tool in the surgical intervention of the more common and lethal types of supraventricular tachyarrhythmias such as atrial flutter and atrial fibrillation. In addition, it also enhances the ability of the investigators to map and ablate the sometimes fleeting automatic atrial tachycardia. The authors developed a 64 channel computerized cardiac mapping system using a microcomputer (Macintosh IIx) and this has been used for basic research in cardiac electrophysiology as well as in arrhythmia surgery. In this system, bipolar electrograms are obtained from 64 different cardiac sites simultaneously at a sampling rate of 1 Ksample/sec and with a continuous and total data storage of up to 30 seconds. When the reference electrode is selected, delay time from the reference point is displayed on a two dimensional diagram of the heart. This system was used in one patient who underwent a surgical ablation of a ventricular tachycardia in whom we observed a ventricular activation sequence involving a variety of rhythms over several minutes. The system design permits easy expansion to a simultaneous sampling from 256 sites. This 64-channel mapping appeared to have the potential to be of great help in our understanding of cardiac arrhythmia as well as in its diagnosis and surgical treatment.