14th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 2000

Jan. 29 - Feb. 5, 2000
Marilleva, Trento, Italy

RT-122

An objective measure of the local organization of human atrial fibrillation from right atrium basket catheter bipolar electrograms

Antonio Michelucci, Piero Bartolini*, Luigi Padeletti, Giovanni Calacagnini*, Andrea Colella, Francesca Censi, Sandra Morelli*, Alessandro Costoli, Paolo Pieragnoli, Silvio Vena, Vincenzo Barbaro*, Gian Franco Gensini.
Istituto di Clinica Medica e Cardiologia, Universita di Firenze, *Laboratorio di Ingegneria Biomedica, ISS, Roma, Italy

Introduction

It has been clearly established that during atrial fibrillation (AF) different regions of the atria may show differing electrophysiologic behaviour^1-3; some regions may show fast, irregular, disorganized atrial activity while, simultaneously, others may be activated by fast but relatively organized and almost regular electrical wavefronts. These different activation patterns may reflect different characteristics of the different parts of the atria, and it can be assumed that the regions showing the most irregular and disorganized activity may be crucial for the maintenance of the arrhythmia, while other regions with relatively regular activation may only be bystanders, and thus ablation in the latter regions may be useless. This is in agreement with the hipothesis recently suggested by Konings et al⁴ that, although the atria partecipate as a whole in the process of AF, not all parts of the atria contribute equally to the perpetuation of the fibrillatory process, suggesting that selective ablation of the areas characterized by abnormal conduction patterns may be effective in the treatment of atrial fibrillation. These data suggest that a measure of the organization of AF could guide ablation therapy by identifying electrophysiologic – rather than anatomic – landmarks to ablate. This is valuable even considering that anatomic approach did not seem able to furnish acceptable results⁵. Despite these statements extensive endocardial mapping studies devoted to analyze organization of atrial acivity during human AF are rare^6,7. Currently available mapping techniques generally use standard electrophysiological catheters with a limited number of electrodes, which are sequentially steered to selected endocardial sites to record local electrical activity or to perform cardiac pacing. Moreover organization of bipolar recordings is achieved by visual scoring and this approach not only is time consuming but also can lead to a non objective and non reproducible analysis. Thus the aim of our study was to overcome these setbacks: 1) using multielectrode basket catheter (MBC) which makes possible simultaneous mapping of the entire atrium; 2) developing an automated method for the quantitative assessment of AF organization.