LAUSR

Pulmonary vein isolation (PVI) using cryoballoon requires contrast medium injection for the confirmation of appropriate venous occlusion. However, some patients have contra-indications against contrast use such as allergy for contrast medium, bronchial asthma or renal dysfunction. We hypothesized that intra-cardiac echocardiographic observation of microbubble leakage after saline injection from the cryoballoon lumen can be used as a maker of incomplete venous occlusion. The aim of this study was to assess the effect of echo-guided approach using saline injection on the acute clinical outcomes as well as the amount of contrast medium. Twenty consecutive patients with paroxysmal atrial fibrillation (AF) were studied. They had any reason to avoid using contrast medium. Plain CT scan was performed in all cases to understand the anatomical features. Intra-cardiac echocardiography was used in all cases to guide transseptal puncture and to confirm pulmonary-vein occlusion. Procedural results and clinical outcomes were compared with patients who were performed by the conventional method (n=279). In all study patients, we could perform PVI without using contrast medium. A total of 2 patients required touch-up ablation using radiofrequency ablation catheter. The procedure time (85±23 vs 86±27 min, P=0.84), the dose of radiation exposure (108±78 vs. 140±133 mmGy/m2, P=0.29), and ratio of requiring touch-up ablation (5% vs 4%, P=0.81) were similar between the study group and the reference group. There was no significant difference in the AF-free survival rate (73% vs. 76%, P=0.79) during a follow-up period of 14±6 months. Images of ICE Echo-guided approach using saline infusion was effective and less invasive in terms of reduction of contrast use.