Fehmi Keçe

Summary and Conclusions 189 9 may improve outcome in persistent AF ablation. In this chapter we have shown that a larger box surface ratio, which is a larger box lesion as a ratio of total left atrial surface area, decreases AF recurrence in these patients. The box lesion surface area can be measured peri-procedurally in the electro-anatomical mapping system and the total left atrial surface area can be measured on pre-procedural CT-scans. We showed that box surface ratio is a stronger predictor for recurrence than left atrium volume index. This study may therefore support a decision to increase the size of the box lesion, e.g. extending it inferiorly below the level of the pulmonary veins towards the coronary sinus, especially in patients with a relatively small anatomical box lesion. Measurement of the box surface ratio and the decision to extend the size of the ablated area in selected patients may improve ablation outcome.