Right anterior oblique (45°) fluoroscopic view with the inflated 28 mm cryoballoon catheter positioned at the ostium of the right inferior pulmonary vein and the AchieveTM inner lumen spiral mapping catheter positioned in the vein. Collimation was used to focus on the area of interest. Contrast injections to demonstrate pulmonary vein occlusion were routinely performed in the standard group, but not in the no-contrast (NC) group.