Transient complete atrioventricular block during transcatheter ablation of a left inferoparaseptal anomalous pathway in a patient with a history of previous surgical repair of ventricular septal defect.

This case describes a young woman with a manifest left inferoparaseptal accessory pathway and previous history of surgical repair of a defect of the ventricular inlet septum in whom a transient complete AV block occurred during radiofrequency ablation performed from the coronary sinus. The presence of a preexisting surgery related AV block unmasked by anomalous pathway ablation is the more reliable explanation for this case.