Safety of Catheter Ablation of Atrial Fibrillation Under Uninterrupted Rivaroxaban Use / Segurança da Ablação por Cateter de Fibrilação Atrial sob Uso Ininterrupto de Rivaroxabana

Abstract Background: Atrial fibrillation (AF) ablation under uninterrupted warfarin use is safe and recommended by experts. However, there is some controversy regarding direct-acting oral anticoagulants for the same purpose. Objective: To evaluate the safety of AF ablation under uninterrupted anticoagulation with rivaroxaban. Methods: A series of 130 patients underwent AF radiofrequency ablation under uninterrupted rivaroxaban use (RIV group) and was compared to a control group of 110 patients under uninterrupted warfarin use (WFR group) and therapeutic International Normalized Ratio (INR). We analyzed death, rates of thromboembolic events, major and minor bleedings, activated clotting time (ACT) levels, and heparin dose in the procedure. The ablation protocol basically consisted of circumferential isolation of the pulmonary veins guided by electroanatomic mapping. It was adopted a statistical significance of 5%. Results: The clinical characteristics of the groups were similar, and the paroxysmal AF was the most frequent type (63% and 59%, RIV and WFR groups). A thromboembolic event occurred in the RIV group. There were 3 patients with major bleeding (RIV = 1 and WFR = 2; p = 0.5); no deaths. Basal INR was higher in the WFR group (2.5 vs. 1.2 ± 0.02; p < 0.0001), with similar basal ACT levels (123.7 ± 3 vs. 118 ± 4; p= 0, 34). A higher dose of venous heparin was used in the RIV group (9,414 ± 199 vs. 6,019 ± 185 IU; p < 0.0001) to maintain similar mean ACT levels during the procedure (350 ± 3 vs. 348.9 ± 4; p = 0.79). Conclusion: In the study population, AF ablation under uninterrupted rivaroxaban showed a safety profile that was equivalent to uninterrupted warfarin use with therapeutic INR.

Resumo Fundamento: A ablação de fibrilação atrial (FA) sob uso ininterrupto de varfarina é segura e recomendada por especialistas. Entretanto, há controvérsia quanto aos anticoagulantes orais de ação direta para o mesmo fim. Objetivo: Avaliar a segurança em realizar ablação de FA sob anticoagulação ininterrupta com rivaroxabana. Métodos: Uma série de 130 pacientes foi submetida à ablação com radiofrequência da FA sob uso ininterrupto de rivaroxabana (grupo RIV) e comparada a um grupo-controle de 110 pacientes que a fizeram sob uso ininterrupto de varfarina (grupo VRF) e relação normatizada internacional (RNI) terapêutica. Analisamos morte, taxas de eventos tromboembólicos, de sangramentos maiores e menores, níveis do tempo de coagulação ativado (TCA) e dose de heparina no procedimento. O protocolo da ablação consistiu basicamente em isolamento circunferencial das veias pulmonares guiado por mapeamento eletroanatômico. Significância estatística de 5% foi adotada. Resultados: As características clínicas dos grupos foram semelhantes e a FA paroxística mais frequente (63% e 59%, grupos RIV e VRF). Um evento tromboembólico ocorreu no grupo RIV. Foram três pacientes com sangramentos maiores (RIV = 1 e VRF = 2; p = 0,5); nenhum óbito. A RNI basal foi maior no grupo VRF (2,5 vs. 1,2 ± 0,02; p < 0,0001), com níveis de TCA basal semelhantes (123,7 ± 3 vs. 118 ± 4; p = 0,34). Maior dose de heparina venosa foi utilizada no grupo RIV (9.414 ± 199 vs. 6.019 ± 185 UI; p < 0,0001) para manter níveis médios de TCA semelhantes durante o procedimento (350 ± 3 vs. 348,9 ± 4; p = 0,79). Conclusão: Na população estudada, a ablação de FA sob rivaroxabana ininterrupta teve segurança equivalente à varfarina ininterrupta, com RNI terapêutica.

Safety of Catheter Ablation of Atrial Fibrillation Under Uninterrupted Rivaroxaban Use.

BACKGROUND: Atrial fibrillation (AF) ablation under uninterrupted warfarin use is safe and recommended by experts. However, there is some controversy regarding direct-acting oral anticoagulants for the same purpose. OBJECTIVE: To evaluate the safety of AF ablation under uninterrupted anticoagulation with rivaroxaban. METHODS: A series of 130 patients underwent AF radiofrequency ablation under uninterrupted rivaroxaban use (RIV group) and was compared to a control group of 110 patients under uninterrupted warfarin use (WFR group) and therapeutic International Normalized Ratio (INR). We analyzed death, rates of thromboembolic events, major and minor bleedings, activated clotting time (ACT) levels, and heparin dose in the procedure. The ablation protocol basically consisted of circumferential isolation of the pulmonary veins guided by electroanatomic mapping. It was adopted a statistical significance of 5%. RESULTS: The clinical characteristics of the groups were similar, and the paroxysmal AF was the most frequent type (63% and 59%, RIV and WFR groups). A thromboembolic event occurred in the RIV group. There were 3 patients with major bleeding (RIV = 1 and WFR = 2; p = 0.5); no deaths. Basal INR was higher in the WFR group (2.5 vs. 1.2 ± 0.02; p < 0.0001), with similar basal ACT levels (123.7 ± 3 vs. 118 ± 4; p= 0, 34). A higher dose of venous heparin was used in the RIV group (9,414 ± 199 vs. 6,019 ± 185 IU; p < 0.0001) to maintain similar mean ACT levels during the procedure (350 ± 3 vs. 348.9 ± 4; p = 0.79). CONCLUSION: In the study population, AF ablation under uninterrupted rivaroxaban showed a safety profile that was equivalent to uninterrupted warfarin use with therapeutic INR.

Taquicardia ventricular polimórfica durante teste de inclinação na doença de Chagas / Polymorphic ventricular tachycardia during tilt testing in Chagas disease

Paciente do sexo masculino, de 62 anos de idade, com megacólon chagásico sem manifestações cardíacas, apresentou evento sincopal sem pródromos, sendo submetido a Holter de 24 horas, ecocardiografia, teste ergométrico e cineangiocoronariografia, que se mostraram normais. O estudo eletrofisiológico mostrou ausência de distúrbios de condução e de indução de taquiarritmias. Durante a fase basal do teste de inclinação, o paciente apresentou taquicardia ventricular polimórfica. Foi realizado implante de cardioversor-desfibrilador implantável. Na evolução, apresentou deterioração da função ventricular com início de terapêutica específica. Após sete anos de acompanhamento, observaram-se três episódios de taquicardia ventricular polimórfica adequadamente revertidos pelo cardioversor-desfibrilador implantável

A 62 year-old man with Chagasic megacolon without cardiac manifestations developed a syncope without prodrome and was submitted to 24-hour Holter monitoring, echocardiogram, exercise test and coronary angiography. Electrophysiology tests showed there was no conduction and tachyarrhythmia induction disorders. During the baseline phase of the tilt test, the patient presented a polymorphic ventricular tachycardia. An implantable cardioverter defibrillator was implanted. At the follow-up, the patient presented left ventricular deterioration and specific therapy was started. After seven years of follow-up, three episodes of polymorphic ventricular tachycardia were observed and were successfully converted

[Radiofrequency catheter ablation of left accessory pathways by transeptal approach]. / Ablação por cateter com radiofreqüência de vias acessórias esquerdas por abordagem transeptal.

OBJECTIVE: To study a series of patients submitted to radiofrequency catheter ablation (RFA) of left accessory pathways (AP) using the transeptal approach (TSA) as compared to the conventional retrograde arterial approach (RAA). METHODS: One hundred consecutive patients (56 male; mean age of 34.3 +/- 11 years) with 100 left APs (62 overt and 38 concealed) underwent catheter ablation using the TS method (50 patients) and the RA method (50 patients) in an alternate fashion. The analysis was performed according to the intention-to-treat principle. RESULTS: The transeptal puncture was successfully performed in 48 patients (96%). This access allowed primary success in the ablation in all the patients without any complication. When we compared this approach with the RAA there was no difference as regards the primary success (p = 0.2), recurrence rate (p = 1.0), fluoroscopy time (p = 0.63) and total time (p = 0.47). One patient in the RAA group presented a vascular complication. The TSA allowed shorter ablation times (p=0.01) and smaller number of radiofrequency applications (p = 0.003) as compared to the conventional RAA. The patients who had recurrence and unsuccessful ablation in the first session in each approach underwent another session with the opposite technique (cross-over), with a final ablation success rate of 100%. CONCLUSION: The TS and RA approaches showed similar efficacy and safety for the ablation of left accessory pathways. The TSA allowed shorter ablation times and smaller number of radiofrequency applications. When the techniques were used in a complementary fashion, they increased the final efficacy of the ablation.

Ablação por cateter com radiofreqüência de vias acessórias esquerdas por abordagem transeptal / Radiofrequency catheter ablation of left accessory pathways by transeptal approach

OBJETIVO: Estudar uma série de pacientes submetidos a ablação por cateter, com radiofreqüência (RF) de vias acessórias (VA) esquerdas mediante abordagem transeptal (TS), comparando-os aos pacientes submetidos ao mesmo tipo de procedimento por abordagem arterial retrógrada (AR) convencional. MÉTODOS: Cem pacientes consecutivos (56 masculinos; 34,3 ± 11 anos de idade), portadores de 100 VA esquerdas (62 manifestas e 38 ocultas) foram submetidos a ablação por cateter por via TS (50 pacientes) e por via AR (50 pacientes), de forma alternada. A análise foi baseada na intenção de tratar. RESULTADOS: A punção transeptal foi realizada com sucesso em 48 (96 por cento) pacientes. Por esse acesso foi obtido sucesso primário na ablação em todos os pacientes e nenhuma complicação foi observada. Ao compararmos com o grupo AR não verificamos diferença em relação ao sucesso primário (p = 0,2), taxa de recorrências (p = 1,0), tempos de fluoroscopia (p = 0,63) e total (p = 0,47). No grupo AR um paciente apresentou complicação vascular. A abordagem TS proporcionou um menor tempo de ablação (p = 0,01) e número de aplicações de RF (p = 0,003) em relação à abordagem AR convencional. As recorrências e insucessos da primeira sessão de cada grupo foram submetidos a novo procedimento pela técnica oposta (cross-over), obtendo-se assim um sucesso final na ablação de 100 por cento. CONCLUSÃO: As abordagens TS e AR apresentam eficácia e segurança semelhantes para ablação de vias acessórias esquerdas. O tempo de ablação e o número de aplicações de RF foram menores com a abordagem TS. Quando as técnicas foram utilizadas de forma complementar, aumentaram a eficácia final da ablação.

Catheter ablation of atriofascicular Mahaim fibers guided by the activation potential.

OBJECTIVE: To determine whether recording of the activation potential may be used as an isolated criterion to guide catheter ablation of atriofascicular Mahaim fibers. METHODS: We studied 6 patients (5 females, mean age of 26 +/- 7.3 years) with paroxysmal tachycardias with a wide QRS complex, whose electrophysiological study diagnosed atriofascicular Mahaim fibers. Mapping and catheter ablation were performed in sinus rhythm, guided only by the recording of the activation potential of the fiber. RESULTS: Efficacy in ablation was achieved in all patients. The fibers were located in the right lateral region of the tricuspid ring in 3 patients, right posterolateral region in 2, and right anterolateral region in 1. A mean of 5.3 +/- 3 radiofrequency applications was performed. The mean fluoroscopy time was 46.6 +/- 25 minutes, and the mean duration of the procedure was 178.6 +/- 108 minutes. No complication occurred. In a mean 20-month follow-up, all patients were asymptomatic and receiving no antiarrhythmic drugs. CONCLUSION: Catheter ablation of Mahaim fibers may be performed with good safety and efficacy by mapping the activation potential of the tricuspid ring in sinus rhythm.

Ablaçäo por cateter de fibras atriofasciculares de Mahaim guiada pelo potencial de ativaçäo / Catheter ablation of atriofascicular Mahaim fibers guided by the activation potential

OBJECTIVE: To determine whether recording of the activation potential may be used as an isolated criterion to guide catheter ablation of atriofascicular Mahaim fibers. METHODS: We studied 6 patients (5 females, mean age of 26±7.3 years) with paroxysmal tachycardias with a wide QRS complex, whose electrophysiological study diagnosed atriofascicular Mahaim fibers. Mapping and catheter ablation were performed in sinus rhythm, guided only by the recording of the activation potential of the fiber. RESULTS: Efficacy in ablation was achieved in all patients. The fibers were located in the right lateral region of the tricuspid ring in 3 patients, right posterolateral region in 2, and right anterolateral region in 1. A mean of 5.3±3 radiofrequency applications was performed. The mean fluoroscopy time was 46.6±25 minutes, and the mean duration of the procedure was 178.6±108 minutes. No complication occurred. In a mean 20-month follow-up, all patients were asymptomatic and receiving no antiarrhythmic drugs. CONCLUSION: Catheter ablation of Mahaim fibers may be performed with good safety and efficacy by mapping the activation potential of the tricuspid ring in sinus rhythm

Procedimentos ablativos por cateter no tratamento da fibrilaçäo atrial / Catheter ablation for the treatment of atrial fibrillation

A alta prevalência da fibrilaçäo atrial, assim como sua morbidade e mortalidade, a ausência de terapêutica farmacológica segura e efetiva, e o entendimento cada vez maior de suas bases fisiopatológicas, tem estimulado o desenvolvimento de terapêuticas näo farmacológicas para a abordagem desta arritmia. Nos pacientes que apresentam fibrilaçäo atrial com alta resposta ventricular e refratária a drogas, a ablaçäo da junçäo AV, com implante de marcapasso, tem se mostrado uma alternativa efetiva, no entanto, restrita ao controle da freqüência cardíaca. A modificaçäo do nó AV pode ser utilizada como primeira tentativa para o controle da freqüência, antes da opçäo definitva, representada pela ablaçäo da junçäo AV. As técnicas propostas de ablaçäo por cateter, baseadas na cirurgia de Cox, carecem de maior esclarecimentos da fisiopatologia da fibrilaçäo atrial, assim como de avanços tecnológicos relacionados aos cateteres e as novas fontes de energia, para que se desenvolvam técnicas mais eficazes, seguras, e de maior aplicabilidade prática. A ablaçäo de focos deflagradores da fibrilaçäo atrial, embora em fase de investigaçäo em relaçäo a sua real eficácia e margem de complicaçöes, traz a expectativa de cura da chamada fibrilaçäo atrial focal