Fehmi Keçe

General Introduction 17 1 1.3 AF-Ablation and outcomes Pulmonary vein isolation is the cornerstone of AF-ablation. Pulmonary vein isolation is associated with AF-Freedom between 60-79%. Late recurrences are in the most of the cases (98%) associated with electrical reconnection of the pulmonary veins, while this is 69-100% in very late recurrences of AF (25). In persistent AF electrical and structural remodelling of the left atrium occurs, requiring additional ablation strategies (14). The currently applied techniques in patients with persistent AF consist of pulmonary vein isolation and/or electrogram based ablation, linear lesions, targeting right atrial sites, autonomic ganglion ablation, rotor ablation, substrate ablation by voltage mapping and isolation of low voltages areas and posterior box lesion ablation (2, 8). 1.3.1 CFAE’s In CFAE ablation complex fractionated signals are targeted in patients with persistent AF. Although originally a high success rate was reported of 76% (Nademanee et al .)(26), this could not be reproduced (27, 28). In subsequent studies AF-freedom was not significantly different from PVI alone (28, 29). 1.3.2 Linear Lesions In linear lesion ablation the goal is to place anatomical barriers to the wave front of the arrhythmia. In the STAR AF II study no benefit was shown of additional linear ablation in patients with persistent AF (29). 1.3.3 Right atrial ablation sites The right atrium, inferior and superior vena cava, crista terminalis and the coronary sinus ostium are possible additional targets in right atrial ablation sites. These areas are borders between different embryonic tissues, capable of spontaneous depolarization (30). The diagnosis is made on the basis of a spontaneous onset of ectopic beats initiating AF during baseline or after provocativemaneuvers with isoproterenol, adenosine and/or atrial pacing. 1.3.4 Autonomic Ganglion ablation Ganglion ablation is shown to be beneficial when combined with pulmonary vein isolation in patients with paroxysmal AF. However in patients with persistent AF, large left atrium and previous catheter ablation it did not result in additional benefits at one year (31, 32).