OBJETIVOS: Analisar o sucesso da ablação circunferencial da fibrilação atrial e investigar possíveis preditores, clínicos e eletroanatômicos, de recorrência da arritmia. MÉTODOS: Foram analisados 104 pacientes consecutivos, submetidos à ablação circunferencial para tratamento de fibrilação atrial paroxística/persistente, sem cardiopatia estrutural e refratários a pelo menos duas drogas antiarrítmicas. Eram do sexo masculino 72 pacientes e a idade média do grupo foi de 58,6 + 10,9 anos. O procedimento consistiu em punção transeptal única e mapeamento tridimensional, com o sistema CARTO® para a aquisição de pontos no átrio esquerdo e veias pulmonares. As aplicações de radiofreqüência foram realizadas ao redor dos óstios das veias pulmonares, até a redução > 80% da amplitude dos potenciais atriais. Uma linha adicional foi criada no istmo mitral e outra no istmo cavotricuspídeo. Foram analisadas: volume total do átrio esquerdo, área ablacionada ao redor das veias pulmonares e a presença ou não de falhas na linha de ablação (linha completa ou incompleta). Foi considerada linha completa quando a distância entre dois pontos contíguos de aplicação de radiofreqüência foi inferior a 10 mm. RESULTADOS: Em acompanhamento médio de 18 meses, 87 pacientes estavam em ritmo sinusal (84%) e 17 pacientes apresentaram recidiva (16%). Na análise multivariada, somente o volume atrial esquerdo (p < 0,0001) e a ablação completa (p <0 ,05) foram preditores independentes de recorrência. CONCLUSÃO: Os resultados sugerem que o volume atrial esquerdo e a presença de ablação completa são preditores de recorrência da fibrilação atrial.

OBJECTIVES: To analyze the success of circumferential ablation on atrial fibrillation and investigate possible clinical and electro-anatomical predictors of the recurrence of cardiac arrhythmia. METHODS: Analysis was done of 104 consecutive patients, free of structural heart disease and refractory to at least 2 antiarrhythmic drugs, submitted to circumferential ablation for treatment of paroxysmal/persistent atrial fibrillation. Were males 72 of the patients and the average age of the group was 58.6 + 10.9. The procedure consisted in a single transeptal puncture and three-dimensional mapping using the CARTO® system. Images of the left atrium and pulmonary veins were reconstructed. Radiofrequency applications were performed around the pulmonary vein ostia, up to a > 80% reduction in atrial potential amplitude. An additional mitral isthmus line was created, as well as one in the cavo-tricuspid isthmus. Total left-atrial volume, area ablated around the pulmonary veins, and the presence or absence of flaws in the ablation line (complete or incomplete line) were analyzed. A line was considered complete when the distance between two contiguous radiofrequency application points was less than 10 mm. RESULTS: After an average follow-up period of 18 months, 87 patients were in sinus rhythm (84%), while 17 patients presented recidivism (16%). In the multivariate analysis only left-atrial volume (p < 0.0001) and complete ablation (p < 0.05) were independent predictors of success. CONCLUSION: These data suggest that the left-atrial volume and the presence of complete ablation are predictors of recurrence.

OBJETIVO: Relatar o perfil de terapias apropriadas (TA) e inapropriadas (TI) do cardioversores-desfibriladores implantáveis (CDI) em portadores de cardiopatia isquêmica e não-isquêmica e as complicações precoces e tardias do procedimento. MÉTODOS: Foram analisados 155 pacientes (119 homens e 36 mulheres), idade média de 47 (21-88) anos, submetidos ao implante de CDI. Foram divididos em grupos I - pacientes pós-infarto agudo do miocárdio (IAM) (n = 80), grupo II - cardiopatia não-isquêmica e fração de ejeção de ventrículo esquerdo (FEVE) < 40% (n = 45): chagásicos (n = 18), portadores de cardiopatia dilatada idiopática (n = 12), hipertensiva (n = 8), hipertrófica (n = 4) e valvar (n = 3); grupo III - displasia arritmogênica do ventrículo direito (n = 13) e grupo IV- canalopatias: síndrome de Brugada (n = 8) e arritmias ventriculares primárias (n = 9). Os pacientes eram submetidos a estudo eletrofisiológico (EEF) antes do implante. RESULTADOS: No seguimento médio de 26 meses foi observado um alto índice (46%) de TA (terapias antitaquicardia e/ou choques) do CDI nos 4 grupos, sem diferença estatística. Os 4 grupos não diferiram na mortalidade total (8,4%) ou arrítmica (1,3%). Não houve correlação entre as TA do CDI e a apresentação clínica dos pacientes ou arritmia ventricular indutível, com 4% de complicações precoces e tardias do procedimento. CONCLUSÃO: A alta incidência de TA do CDI e a baixa incidência de morte súbita sugerem que o CDI é uma estratégia terapêutica valiosa no manejo de pacientes isquêmicos e não isquêmicos selecionados previamente com EEF.

OBJECTIVE: To report appropriate (AT) and inappropriate (IT) ICD therapies in patients with ischemic and nonischemic heart disease, as well as early and late procedure-related complications. METHODS: One hundred and fifty-five patients (119 male and 36 female), mean age 47 years (21-88), who underwent ICD implantation between 1994 and March 2003 were analyzed. Patients were divided into the following groups: Group I - Post-AMI patients (n = 80); Group II - Patients with nonischemic heart disease and LV ejection fraction < 40% (n = 45), Chagas disease (n = 18), idiopathic dilated cardiomyopathy (n= 12), hypertensive disease (n = 8), hypertrophic cardiomyopathy (n = 4) and valvular heart disease (n = 3); Group III - Patients with arrhythmogenic right ventricular dysplasia (n = 13); and Group IV - Patients with channelopathies: Brugada Syndrome (n = 8) and idiopathic ventricular arrhythmias (n = 9). All patients underwent electrophysiological study (EPS) with induction of sustained ventricular arrhythmia ICD implantation. RESULTS: During the 26-month mean follow up, a high rate of appropriate ICD therapies (antitachycardia pacing and/or shock) was observed (46%) in the four groups, with no statistically significant difference. The four groups did not differ in either overall (8.4%) or arrhythmic mortality (1.3%). There was no correlation between appropriate ICD therapies and initial clinical presentation or inducible ventricular arrhythmia at EPS, and a 4% incidence of early and late procedure-related complications was found. CONCLUSION: The high incidence of appropriate ICD therapy and low rate of sudden death in the patients studied suggest that ICD is a valuable strategy in the management of ischemic and nonischemic patients previously selected by means of EPS.

OBJECTIVE: To assess the clinical, electrocardiographic, and electrophysiologic characteristics of patients (pt) with intra-His bundle block undergoing an electrophysiologic study (EPS). METHODS: We analyzed the characteristics of 16 pt with second-degree atrioventricular block and symptoms of syncope or dyspnea, or both, undergoing conventional EPS. RESULTS: Intra-His bundle block was documented in 16 pt during an EPS. In 15 (94%) pt, the atrioventricular block was recorded in sinus rhythm; 4 (25%) pt had intra-His Wenckebach phenomenon, which correlated with Mobitz I (MI) atrioventricular block on the electrocardiogram. Seven (44%) pt had 2:1 atrioventricular block, 2 of whom were asymptomatic (12.5%). One (6%) pt had intra- and infra-His bundle block. Clinically, 11 (68%) pt had syncope or presyncope, 3 (18%) had dyspnea on exertion, and 2 (12.5%) were asymptomatic. Eight (50%) pt had bundle-branch block as follows: 4 (25%) pt had left bundle-branch block, and 4 (25%) had right bundle-branch block. Left anterosuperior divisional block was observed in 3 pt (19%), 2 of whom with associated right bundle-branch block. CONCLUSION: Intra-His bundle block was observed in 11% of the pt with second-degree atrioventricular block, syncope or presyncope, or both, it being the most frequent clinical presentation. Intra-His bundle block was more common in the elderly (> 60 years) and among females. The most frequent electrocardiographic presentations were second-degree Mobitz I or type 2:1 atrioventricular block.