VALUE OF UNIPOLAR AND BIPOLAR RECORDINGS IN RADIOFREQUENCY ABLATION OF ACCESSORY ATRIOVENTRICULAR PATHWAYS

The aim of the study was to compare the value of different modes of en docavitary recordings : unipolar alone, bipolar alone and the associat ion of unipolar and bipolar recordings in radiofrequency ablation of a ccessory atrioventricular pathways. A retrospective analysis by three independent observers of 135 endocavitary recordings obtained immediat ely before radiofrequency application in 82 subjects who underwent rad iofrequency ablation for symptomatic accessory atrioventricular pathwa ys. In each case, the authors selected the ''successful'' record which corresponded to the final radiofrequency application and 0, 1 or 2 re cords of ''failures''. Each initial recording being of 3 types (unipol ar, bipolar and association of uni- and bipolar), a total of 390 anony mous and randomised recordings were analysed by the observers who dete rmined whether the appearances indicated successful ablation. Univaria te analysis of variants showed a correlation between success with the mode of recording (p = 0.03) and a left lateral position of the access ory pathways. In multivariate analysis, three variables remained corre lated with successful ablation :the observer variable (p = 0.001), and two interactions observer - mode (p = 0.005) and observer-stability ( p = 0.02). The benefits of the association of unipolar and bipolar rec ordings with respect to bipolar recording alone, seemed to be importan t in predicting failure. The results of tests of concordance in the gr oup of failures were confirmatory : concordance between observers was only found between the unipolar mode alone and the association of unip olar and bipolar recordings. The results of this study suggest that th e association of unipolar and bipolar endocavitary recordings may redu ce the number of unnecessary application of radiofrequency energy by i mproved identification of recording showing failure.