Initial procedure
Postero-septal accessory pathways (n=8, 21%) presented with the highest number of non-successful applications and the longest procedure length. Three patients (38%) had pathways located deep in the septal area requiring bi-atrial applications. Two patients (25%) presented with a diverticulum of the coronary sinus (Figure 4). The cause leading to recurrence in these cases was probable multiple including lack of lesion depth, epicardial location and poor delivery of energy when lesions were located within the coronary sinus.