272 Efficacy of cryocatheter ablation as alternative treatment for atrioventricular reentrant tachycardia: A randomized study

to SR during ablation and with administration of ibutilide. Only 1 patient had linear ablation with a roof and superior coronary sinus line while 2 had a cavotricuspid isthmus ablation. Mean follow up was 6 (range 1-12) months. Those patients that maintained SR had a mean LA volume and surface area of 58.5 11.8ml/m and 164.5 29.8cm vs 76.1 24.2 ml/m(P 0.01). There was no significant difference between the amount of fluoroscopy or ablation time between the two groups (P 0.2, 0.6, respectively).There was no clear cutoff based on LA volume to predict long term patient outcome, but a ROC analysis showed that an LA surface area 176 cm (sensitivity 1.00 and specificity 0.86 , AUC 0.88) predicted recurrence of AF in this sample. CONCLUSION: Patients undergoing LA ablation for persistent AF are more likely to have recurrence of AF with markedly dilated left atria and with an LA surface area 176 cm. There is no difference in the distribution or type of CFEs.