Clinical introduction

During a routine ablation for paroxysmal atrial fibrillation, the right superior pulmonary vein was isolated using the cryoballoon. This was the final vein to be isolated. After the freeze, as the balloon was deflated and withdrawn, a radio-opaque structure was seen to mobilise from the vein ostium (figure 1A). This structure moved into the left atrium (figure 1B), left ventricle, aortic arch (figure 1C) and descending aorta (figure 1D) in turn (full fluoroscopic run available as online supplementary video file). The patient experienced no new …