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

Abstract

BACKGROUND. It has been suggested that a measure of the organization of the atrial fibrillation (AF) could guide ablation therapy by identifying electrophysiologic – rather than anatomic – landmarks to ablate. Organization of bipolar recordings is usually achieved by visual scoring and this approach not only is time consuming but also can lead to a non objective and non reproducible analysis. Moreover multielectrode basket catheter (MBC) makes now possible simultaneous mapping of the entire atrium. Thus the aim of our study was to develop an automated method for the quantitative assessment of AF organization applicable to recordings obtained by MBC.

METHODS. Thirty-two bipolar electrograms were obtained from MBC in right atrium in 5 informed chronic AF patients. Degree of organization was assessed by computing the number of occurrences (NO) over segment of 4 seconds. Sensitivity (Se), specificity (Sp) and total correct classification rate (TCCR) of the classification of organization using NO were tested on data set of 160 segments of AC:\WWW 60 type I, 40 type II and 60 type III. Organization maps of the whole atrium were constructed by bidimensional cubic-spline interpolation from the measures at the electrode sites. Interpolation used a realistic model of the MBC displacement, obtained from the fluoroscopic projections.

RESULTS. The Se and Sp of type I AF were respectively 90 and 98.33%, of type II 85 and 91.25, of type III 92.5% and 96.67%; the TCCR was 90%. Organization maps were obtained in all the patients. Organization patterns varied over the time and were spatially distributed according to individual patterns.

CONCLUSIONS. NO, using MBC, provides an objective measurement of the local degree of organization thus being suitable for rapid identification of sites with similar electrophysiological pattern. This approach meets reasonable criteria for rapid endocardial mapping and ablation of AF.

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