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FUNDAMENTO: A complexidade dos circuitos reentrantes relacionados às taquicardias ventriculares diminui os índices de sucesso dos procedimentos de ablação por radiofrequência. OBJETIVO: Avaliar se o mapeamento epicárdico com múltiplos eletrodos realizado simultaneamente com o mapeamento endocárdico auxilia na ablação da taquicardia ventricular (TV) sustentada em pacientes com cardiopatia não isquêmica. MÉTODOS: Vinte e seis pacientes com TV sustentada recorrente, sendo 22 (84,6%) com cardiopatia chagásica crônica, dois (7,7%) com cardiomiopatia dilatada idiopática e dois (7,7%) portadores de displasia arritmogênica do ventrículo direito, foram submetidos a mapeamento epicárdico com dois ou três microcateteres, com 8 eletrodos cada, simultaneamente ao mapeamento endocárdico convencional. Utilizou-se cateter com ponta de 4 mm para ablação com radiofrequência (RF) realizada durante a TV induzida. RESULTADOS: Das 33 TVs induzidas, 25 foram mapeadas e 20 tiveram sua origem definida. Onze com origem epicárdica e 9 endocárdica. A estimulação ventricular programada não induziu TV sustentada em 11 (42,0%) dos 26 pacientes após a ablação. Eventos como recorrência da TV e morte ocorreram em 10,0% dos pacientes submetidos à ablação com sucesso, e em 59,0% dos insucessos, em seguimento ambulatorial médio de 357 ± 208 dias. CONCLUSÃO: Circuitos subepicárdicos são frequentes em pacientes com cardiopatia não isquêmica. O mapeamento epicárdico com múltiplos cateteres realizado simultaneamente com o mapeamento endocárdico contribui para a identificação destes circuitos em um mesmo procedimento. BACKGROUND: The complexity of reentrant circuits related to ventricular tachycardias decreases the success rate of radiofrequency ablation procedures. OBJECTIVE: To evaluate whether the epicardial mapping with multiple electrodes carried out simultaneously with the endocardial mapping helps in ablation procedures of sustained ventricular tachycardia (VT) in patients with nonischemic heart disease. METHODS: Twenty-six patients with recurrent sustained VT, of which 22 (84.6%) presenting chronic chagasic cardiomyopathy, 2 (7.7%) with idiopathic dilated cardiomyopathy and 2 with right ventricular arrhythmogenic dysplasia (RVAD), were submitted to epicardial mapping with two or three microcatheters, with 8 electrodes each, simultaneously to the conventional endocardial mapping. A catheter with a 4-mm tip was used for the ablation by radiofrequency (RF) carried out during the induced VT. RESULTS: Of the 33 induced VT, 25 were mapped and 20 had their origin defined. Eleven had epicardial and 9 had endocardial origin. The programmed ventricular stimulation did not induce sustained VT in 11 (42.0%) of the 26 patients after the ablation. Events such as VT recurrence and death occurred in 10.0% of the patients submitted to successful ablation and in 59.0% of the unsuccessful cases, during a mean ambulatory follow-up of 357 ± 208 days. CONCLUSION: Subepicardial circuits are frequent in patients with nonischemic heart disease. The epicardial mapping with multiple catheters carried out simultaneously with the endocardial mapping contributes to the identification of these circuits in a same procedure. FUNDAMENTO: La complejidad de los circuitos reentrantes relacionados a las taquicardias ventriculares disminuye los índices de éxito de los procedimientos de ablación por radiofrecuencia. OBJETIVO: Evaluar si el mapeo epicárdico con múltiples electrodos realizado simultáneamente con el mapeo endocárdico ayuda en la ablación de la taquicardia ventricular (TV) sostenida en pacientes con cardiopatía no isquémica. MÉTODOS: Veinte y seis pacientes con TV sostenida recurrente, siendo 22 (84,6%) con cardiopatía chagásica crónica, dos (7,7%) con cardiomiopatía dilatada idiopática y dos (7,7%) portadores de displasia arritmogénica del ventrículo derecho, fueron sometidos a mapeo epicárdico con dos o tres microcatéteres, con 8 electrodos cada uno, simultáneamente al mapeo endocárdico convencional. Se utilizó catéter con punta de 4 mm para ablación con radiofrecuencia (RF) realizada durante la TV inducida. RESULTADOS: De las 33 TVs inducidas, 25 fueron mapeadas y 20 tuvieron su origen definido. Once con origen epicárdica y 9 endocárdica. La estimulación ventricular programada no indujo TV sostenida en 11 (42,0%) de los 26 pacientes después de la ablación. Eventos como recurrencia de la TV y muerte ocurrieron en 10,0% de los pacientes sometidos a la ablación con éxito, y en 59,0% de los fracasos, en control ambulatorio medio de 357 ± 208 días. CONCLUSIÓN: Circuitos subepicárdicos son frecuentes en pacientes con cardiopatía no isquémica. El mapeo epicárdico con múltiples catéteres realizado simultáneamente con el mapeo endocárdico contribuye a la identificación de estos circuitos en un mismo procedimiento.

The complexity of reentrant circuits related to ventricular tachycardias decreases the success rate of radiofrequency ablation procedures.To evaluate whether the epicardial mapping with multiple electrodes carried out simultaneously with the endocardial mapping helps in ablation procedures of sustained ventricular tachycardia (VT) in patients with nonischemic heart disease.Twenty-six patients with recurrent sustained VT, of which 22 (84.6%) presenting chronic chagasic cardiomyopathy, 2 (7.7%) with idiopathic dilated cardiomyopathy and 2 with right ventricular arrhythmogenic dysplasia (RVAD), were submitted to epicardial mapping with two or three microcatheters, with 8 electrodes each, simultaneously to the conventional endocardial mapping. A catheter with a 4-mm tip was used for the ablation by radiofrequency (RF) carried out during the induced VT.Of the 33 induced VT, 25 were mapped and 20 had their origin defined. Eleven had epicardial and 9 had endocardial origin. The programmed ventricular stimulation did not induce sustained VT in 11 (42.0%) of the 26 patients after the ablation. Events such as VT recurrence and death occurred in 10.0% of the patients submitted to successful ablation and in 59.0% of the unsuccessful cases, during a mean ambulatory follow-up of 357 ± 208 days.Subepicardial circuits are frequent in patients with nonischemic heart disease. The epicardial mapping with multiple catheters carried out simultaneously with the endocardial mapping contributes to the identification of these circuits in a same procedure.

Objective - To demonstrate the feasibility and safety of simultaneous catheterization and mapping of the 4 pulmonary veins for ablation of atrial fibrillation. Methods - Ten patients, 8 with paroxysmal atrial fibrillation and 2 with persistent atrial fibrillation, refractory to at least 2 antiarrhythmic drugs and without structural cardiopathy, were consecutively studied. Through the transseptal insertion of 2 long sheaths, 4 pulmonary veins were simultaneously catheterized with octapolar microcatheters. After identification of arrhythmogenic foci radiofrequency was applied under angiographic or ultrasonographic control. Results - During 17 procedures, 40 pulmonary veins were mapped, 16 of which had local ectopic activity, related or not with the triggering of atrial fibrillation paroxysms. At the end of each procedure, suppression of arrhythmias was obtained in 8 patients, and elimination of pulmonary vein potentials was accomplished in 4. During the clinical followup of 9.6±3 months, 7 patients remained in sinus rhythm, 5 of whom were using antiarrhythmic drugs that had previously been ineffective. None of the patients had pulmonary hypertension or evidence of stenosis in the pulmonary veins. Conclusion - Selective and simultaneous catheterization of the 4 pulmonary veins with microcatheters for simultaneous recording of their electrical activity is a feasible and safe procedure that may help ablation of atrial fibrillation.

Successful radiofrequency catheter ablation of ectopic beats originating from the pulmonary veins can eliminate paroxysmal atrial fibrillation (AF),1–4 but the complex anatomy of this region may limit mapping of AF. Information about the structure of the pulmonary veins and left atrial junction is poorly reported, especially in the adult population.