Predicting the arrhythmogenic foci of atrial fibrillation before atrial transseptal procedure: Implication for catheter ablation

Introduction: Use of endocardial atrial activation sequences from recording catheters in the right atrium, His bundle, and coronary sinus to predict the location of initiating loci of atrial fibrillation (AF) before an atrial transseptal procedure has not been reported. The purpose of the present study was to develop an algorithm using endocardial atrial activation sequences to predict the location of initiating loci of AF before transseptal procedure. Methods and Results: Seventy-five patients (60 men and 15 women, age 68 ± 12 years) with frequent episodes of paroxysmal AF were referred for radiofrequency ablation. By retrospective analysis, characteristics of the endocardial atrial activation sequences of right atrial, His-bundle, and coronary sinus catheters from the initial 37 patients were correlated with the location of initiating loci of AF, which were confirmed by successful ablation. The endocardial atrial activation sequences of the other 38 patients were evaluated prospectively to predict the location of initiating loci of AF before transseptal procedure using the algorithm derived from the retrospective analysis. Accuracy of the value