RÉSUMÉ
Relata-se o caso de uma paciente que, durante troca do gerador do marcapasso definitivo, foi tratada com propafenona após desenvolver fibrilação atrial no período intraoperatório. Os limiares eram moderadamente aumentados no pré-operatório, entretanto, estáveis. Horas após a administração de 600 mg de propafenona, a paciente apresentou síncope justificada pela perda de comando ventricular. A avaliação do dispositivo mostrava perda de captura por aumento do limiar ventricular medido em 5,0V/0,6 ms, corrigida por estimulação com energia máxima de saída do gerador. No dia seguinte, após nova avaliação, o limiar havia retornado ao valor previamente aferido e a energia de saída do gerador diminuiu, mantendo-se estável após seis meses de seguimento...
This is the case report of a patient who was treated with propafenone during the exchange of a permanent pacemaker generator, after the development of atrial fibrillation during the procedure. The thresholds were moderately increased in the preoperative period, however, they were stable. Hours after the administration of 600 mg of propafenone, the patient had a syncope which was explained by the loss of ventricular command. The evaluation of the device showed there was loss of capture due to the ventricular threshold increase, which as measured as 5.0V/0.6 ms and was adjusted by stimulation with maximum outlet energy of the generator. On the following day, after a new assessment, the values had returned to normal, the generator outlet energy decreased, and remained stable after six months of follow-up...