Eliminação de potenciais tardios para ablação de taquicardia ventricular em pacientes com cardiomiopatia chagásica crônica
Data
2022-12-06
Autores
Dietrich, Cristiano de Oliveira 
Orientadores
Paola, Angelo Amato VIncenzo de
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Introdução: Os pacientes com cardiomiopatia chagásica crônica (CCC) e taquicardia ventricular (TV) apresentam importante morbi-mortalidade. A ablação por cateter de TV nesta população ainda continua um desafio. Os resultados da ablação de TV mapeáveis são satisfatórios, mas têm curto período de acompanhamento clínico. A técnica de ablação com modificação do substrato guiando-se por potenciais tardios ou eletrogramas anormais demonstrou-se útil em pacientes com cardiopatia isquêmica e não isquêmica. Objetivos: O objetivo principal deste estudo foi avaliar a eficácia da ablação por cateter guiada pelos potenciais tardios no controle da TV em pacientes com CCC. Métodos: Dezessete pacientes com CCC foram submetidos à ablação por cateter devido a TV recorrente e refratária ao tratamento antiarrítmico. O mapeamento do substrato foi efetuado através de mapa codificado por cores, voltagem e ativação, durante o ritmo sinusal ou marcapasso. Dessa forma, áreas de baixa voltagem e ativação tardia foram definidas e usadas para guiar a ablação por cateter com a intenção de eliminar todos os potenciais tardios no endocárdio e epicárdio ventricular. Resultados: Um total de 63 TV foram induzidas pela estimulação ventricular programada (ciclo de frequência médio = 382 ms). Baixa voltagem epicárdica e endocárdica (voltagem de eletrograma <1,5 mV) foram encontradas em 17/17 e 15/17 pacientes, respectivamente. Áreas exibindo potenciais tardios foram detectadas dentro da cicatriz epicárdica em 16/17 pacientes e, na cicatriz endocárdica, em 14/15 pacientes. Todas as 22 TV encarrilhadas demonstraram potenciais tardios nos sítios de istmo central. O desfecho principal, eliminação completa dos eletrogramas tardios, foi atingido em 15 dos 17 pacientes. Ablação não foi completada em 2 pacientes por causa de tamponamento cardíaco ou proximidade do nervo frênico e ramo coronariano com a área de interesse. Durante o seguimento clínico de 39 meses, 14 dos 15 pacientes com sucesso imediato permaneceram livres de episódios de TV a despeito da redução significativa na dose de amiodarona. Três dos 17 pacientes tiveram recorrência de TV. Conclusões: Em pacientes com CCC e TV refratária, o mapeamento concomitante do substrato endocárdico e epicárdico durante o ritmo de base demonstrou-se útil para identificar o complexo circuito de diferentes TV e permitiu o tratamento efetivo e seguro através da abolição dos potenciais tardios.
Background: Chronic Chagas cardiomyopathy (CCC) was related to ventricular tachycardia (VT) and considered morbidity and mortality. Catheter ablation of VT in patients with CCC still continues a challenge. Catheter ablation during mappable VT are satisfactory but presents short-time of follow-up. Substrate ablation guided by late potential or abnormal electrograms has been show useful in patients with ischemic and non-ischemic cardiomyopathy. Objectives: The main goal of this work was to assess efficacy of late potential guided catheter ablation of VT in patients with CCC. Methods: Seventeen patients with CCC underwent catheter ablation for recurrent VT at least one antiarrhythmic drug failed. Substrate mapping was performed through color-codec voltage and activation maps during basic rhythm. Therefore, low voltage and late activation area defined during baseline rhythm was used to guide the catheter ablation to eliminate all late potential. Results: A total of 63 VTs were induced in 17 patients (cycle length 382ms). Epicardial and endocardial low voltage (<1,5 mV) areas were detected in 17/17 and 15/17 patients, respectively. Areas exhibiting late potentials were detected within the epicardial scar in 16/17 patients and the endocardial scar in 14/15 patients. All 22 entrained VTs recorded late potentials in the isthmus sites. Immediate endpoint of ablation was achieved in 15 of 17 patients. Ablation was not completed in 2 patients because of cardiac tamponade or vicinity of phrenic nerve and circumflex artery. During long-term follow-up (39 months), 14 of 15 patients with a successful procedure were still free of VT despite of significantly reduction of amiodarone, and 3 patients of total group (17 patients) had recurrence of VT. Conclusions: In patients with CCC and drug-refractory VTs, concomitant endoepicardial substrate mapping during baseline rhythm helped to identify the putative isthmuses of different induced VTs and allowed for effective and safety treatment by catheter ablation.
Background: Chronic Chagas cardiomyopathy (CCC) was related to ventricular tachycardia (VT) and considered morbidity and mortality. Catheter ablation of VT in patients with CCC still continues a challenge. Catheter ablation during mappable VT are satisfactory but presents short-time of follow-up. Substrate ablation guided by late potential or abnormal electrograms has been show useful in patients with ischemic and non-ischemic cardiomyopathy. Objectives: The main goal of this work was to assess efficacy of late potential guided catheter ablation of VT in patients with CCC. Methods: Seventeen patients with CCC underwent catheter ablation for recurrent VT at least one antiarrhythmic drug failed. Substrate mapping was performed through color-codec voltage and activation maps during basic rhythm. Therefore, low voltage and late activation area defined during baseline rhythm was used to guide the catheter ablation to eliminate all late potential. Results: A total of 63 VTs were induced in 17 patients (cycle length 382ms). Epicardial and endocardial low voltage (<1,5 mV) areas were detected in 17/17 and 15/17 patients, respectively. Areas exhibiting late potentials were detected within the epicardial scar in 16/17 patients and the endocardial scar in 14/15 patients. All 22 entrained VTs recorded late potentials in the isthmus sites. Immediate endpoint of ablation was achieved in 15 of 17 patients. Ablation was not completed in 2 patients because of cardiac tamponade or vicinity of phrenic nerve and circumflex artery. During long-term follow-up (39 months), 14 of 15 patients with a successful procedure were still free of VT despite of significantly reduction of amiodarone, and 3 patients of total group (17 patients) had recurrence of VT. Conclusions: In patients with CCC and drug-refractory VTs, concomitant endoepicardial substrate mapping during baseline rhythm helped to identify the putative isthmuses of different induced VTs and allowed for effective and safety treatment by catheter ablation.