Nonsurgical transthoracic epicardial radiofrequency ablation: an alternative in incessant ventricular tachycardia.

OBJECTIVES: The purpose of this study was to analyze the feasibility, efficacy, and safety of epicardial radiofrequency (RF) ablation in patients with incessant ventricular tachycardia (VT). BACKGROUND: Management of patients with incessant VT is a difficult clinical problem. Drugs and RF catheter ablation are not always effective. A nonsurgical transthoracic epicardial RF ablation can be an alternative in patients refractory to conventional therapy. METHODS: Epicardial RF ablation was performed in 10 patients who presented with incessant VT despite the use of two or more intravenous antiarrhythmic drugs. RESULTS: In eight patients, endocardial ablation (EdA) failed to control the tachycardia. In the remaining two patients, epicardial ablation (EpA) was first attempted because of left ventricular thrombus and severe artery disease, respectively. Eight patients had a diagnosis of coronary artery disease with healed myocardial infarction. One patient had dilated cardiomyopathy, and one patient had idiopathic, incessant VT. In patients with structural heart disease, the mean ejection fraction was 0.28 +/- 0.10%. Four patients previously received an implantable defibrillator. The EpA effectively terminated the incessant tachycardia in eight patients, which represents a success rate of 80%. In them, after a follow-up of 18 +/- 18 months, a single episode of a different VT was documented in one patient. No significant complications occurred related to the procedure. CONCLUSIONS: In patients with incessant VT despite the use of drugs or standard EdA, the epicardial approach was very effective and should be considered as an alternative in this life-threatening situation.

[Radiofrequency ablation in the treatment of focal atrial fibrillation using circumferential mapping and segmentary disconnection of pulmonary veins]. / Ablación por radiofrecuencia para el tratamiento de la fibrilación auricular focal a través de cartografía circunferencial y aislamiento segmentario de las venas pulmonares.

INTRODUCTION: The treatment of paroxysmal atrial fibrillation in patients without structural heart disease using radiofrequency ablation of pulmonary veins is a recently developed procedure with a good clinical success rate, although there have only been a few published series. We analyzed our results with this technique. METHOD: The procedure was performed in 33 highly symptomatic patients with focal atrial fibrillation that had probably originated in the pulmonary veins. The electrophysiological study was carried out with a decapolar catheter inserted by transeptal catheterization. Ablation was performed using a 4-mm catheter and directed to the segments of the ostium of pulmonary veins where venous potentials with greatest precocity were recorded. Subsequent radiofrecuency applications were performed until pulmonary vein disconnection was achieved. RESULTS: Venous electrical activity was recorded in 59 of 115 pulmonary veins that were mapped (58 were disconnected). During a median follow-up of 180 days, 8 patients recurred and only 2 of these continue with repeat episodes. The success rate at short term was 74.2% and at mid-term was 93.5%. Nineteen patients continue to receive antiarrhythmic treatment innefective before the procedure. Two patients showed complications related to catheter manipulation during tansseptal catheterization, probably due to air embolism, that was resolved spontaneously without consequences. No patient showed pulmonary stenosis. CONCLUSIONS: Teatment of focal atrial fibrillation using circumferential mapping and radiofrecuency application in segments of the ostium of pulmonary veins is a highly effective procedure in selected patients and has potentially severe although infrequent complications.

Electrical interference from an abdominal muscle stimulator unit on an implantable cardioverter defibrillator: report of two consecutive cases.

Two consecutive cases are presented of patients with ICDs in whom the use of commercial units for muscle stimulation for abdominal training caused interference with the device, mimicked cardiac signals, and resulted in inappropriate treatment shock delivery.

Ablación por radiofrecuencia para el tratamiento de la fibrilación auricular focal a través de cartografía circunferencial y aislamiento segmentario de las venas pulmonares / Radiofrequency ablation in the treatment of focal atrial fibrillation using circumferential mapping and segmentary disconnection of pulmonary veins

Introducción. El tratamiento de la fibrilación auricular paroxística en pacientes sin cardiopatía estructural a través de la ablación con radiofrecuencia de las venas pulmonares es un procedimiento reciente y con una tasa de éxito clínico importante, aunque las series publicadas son escasas. Analizamos nuestros resultados. Método. Fueron sometidos al procedimiento 33 pacientes muy sintomáticos y en fibrilación auricular de probable origen focal en venas pulmonares. Se realizó cartografía con un catéter decapolar por punción transeptal. Se utilizó un catéter de 4 mm para ablación de los segmentos del ostium de las venas donde se registraba el potencial eléctrico venoso con mayor precocidad, y se aplicó radiofrecuencia hasta obtener la desconexión de la vena pulmonar. Resultados. Se registró actividad eléctrica en 59 de 115 venas pulmonares cartografiadas (58 fueron desconectadas). Durante un seguimiento medio de 180 días, 8 pacientes presentaron recurrencia de la arritmia y de éstos sólo dos siguen con episodios repetitivos. La tasa de éxito a corto plazo fue del 74,2 por ciento y a medio plazo, del 93,5 por ciento. Diecinueve pacientes reciben tratamiento antiarrítmico antes inefectivo. Dos pacientes presentaron complicaciones en relación con el manejo de catéteres durante la punción transeptal, probablemente por embolia gaseosa, que se resolvieron espontáneamente sin secuelas. Ningún paciente presentó signos o síntomas de estenosis pulmonar. Conclusiones. El tratamiento de la fibrilación auricular focal a través de cartografía circunferencial y aplicación de radiofrecuencia en segmentos del ostium de las venas pulmonares es un procedimiento de gran eficacia en pacientes seleccionados y con complicaciones potencialmente graves pero infrecuentes (AU)