[Electrofulguration of a pre-excitation zone by the bundle of Kent].

The purpose of this presentation is to report the first endocardial catheter ablation in Mexico of a right posteroseptal accessory pathway. The patient, without structural heart disease, had a Wolff Parkinson White syndrome with recurrent episodes of paroxysmal supraventricular tachycardia and atrial fibrillation with a fast ventricular response, through the accessory pathway (Shorter RR interval less than or equal to 190 msec). Previous antiarrhythmic drug therapy had failed to control the tachyarrhythmias. An electrophysiologic study was performed and the right posterior septal accessory pathway was localized by direct mapping of the auriculoventricular junction. Two sessions of electrofulguration with energy shocks ranging from 200 to 250 joules were delivered. There were no complications during the two procedures. Three months afterwards the patient is asymptomatic without tachyarrhythmic episodes, and no drug therapy is necessary. The fulguration prolonged the anterograde accessory pathway conduction. Therefore, the risk of sudden cardiac death due ventricular fibrillation has been reduced.