[Radiofrequency ablation of the atrioventricular accessory pathways. Value of unipolar and bipolar recordings]

Radiofrequency catheter ablation has become the treatment of choice of arrhythmias related to accessory atrioventricular pathways. The reported success rate is well over 90%, irrespective of the localisation of the accessory pathway, and serious complications are rare. A basic principle of the technique is the limitation of the number of applications of radiofrequency energy during a session of ablation and this requires mapping to determine the ideal site using various electrographic parameters. With regards to bipolar recordings, they include: the atrioventricular conduction time, localisation of the ventricular pole of the accessory pathway, recording the accessory pathway potential, the atrial pole of the accessory pathway, and stability of the catheter position. However, the parameters are not readily reproducible and the positive predictive value for successful ablation is low. The use of unipolar electrograms could therefore represent a fundamental step in improving the localisation of accessory pathways and thereby reducing the number of useless applications of radiofrequency energy.