Concealed accessory pathway with long conduction times and incremental properties: a case report.

Concealed AP with Slow and Incremental Conduction. We report a peculiar form of permanent junctional reciprocating tachycardia that occurs only during daytime and physical activity. ECG obtained during tachycardia showed an unusual progressive shortening of the ventriculoatrial (VA) interval that was maximal at the first complex and shortest at the last one before block occurred, always at the accessory pathway level. This phenomenon has not been previously described and appears to be a reverse type of Wenckebach block. It was observed during salvos of spontaneous tachycardia and could be reproduced by right ventricular pacing. The accessory pathway was ablated successfully at the right posteroseptal region, close to the coronary sinus ostium. After ablation, there was no VA conduction, and tachycardia did not recur during a 9-month follow-up period.

[Ventricular fibrillation in a patient with the permanent form of junctional reciprocating tachycardia]. / Fibrilação ventricular em paciente com forma permanente da taquicardia juncional reciprocante.

A case of a 20 year old young man having the permanent form of junctional reciprocating tachycardia complicated by ventricular fibrillation (VF) is reported. A number of antiarrhythmic drugs either as single or combined therapy fail to control tachycardia. Paroxisms of a faster palpitation which never lasted longer than a few minutes were felt over the last six months before the occurrence of VF. At admission, a narrow QRS tachycardia 250 beats/min was recorded and soon degenerated into VF. After electrical shock with 350J permanent form of junctional tachycardia resumed. Electrophysiologic evaluation identified an accessory pathway with long conducting times in postero-septal location, enhanced atrioventricular node conduction and inducible atrial flutter. The patient underwent successful radiofrequency ablation and is doing well after 18 months of follow-up, being off antiarrhythmic drug and tachycardia free.

Fibrilação; ventricular em pacientes com forma permanente da taquicardia juncional reciprocante / Ventricular fibrillation in a patient with the permanent form of junctional reciprocating tachycardia

Homem de 20 anos, portador de taquicardia de apresentaçäo incessante há longos anos, sem resposta a medicaçöes antiarrítmicas. Seis meses antecedendo a admissäo referia paroxismos de taquicardia mais rápida, de duraçäo curta, autolimitada. Na admissäo apresentava flutter atrial com conduçäo 1:1 (250 bpm) que degenerou em fibrilaçäo ventricular, revertida com 350J. O estudo eletrofisiológico identificou taquicardia atrioventricular, utilizando conexäo anômala "oculta" de localizaçäo póstero-septal deita com conduçäo lenta e propriedade decremental, conduçäo atrioventricular acelerada, observando-se precipitaçäo de fibrilaçäo atrial com resposta rápida pós-atropinizaçäo. Foi submetido a ablaçäo por cateter pro radiofrequência com sucesso. Esta assintomático, 18 meses após o procedimento.