Congenital narrowing of a pulmonary vein: slit-like pulmonary vein ostium.

We report the case of a 60-year-old female with a history of refractory paroxysmal atrial fibrillation. Preablation contrast enhanced pulmonary vein computed tomography (CT) scan demonstrated a slit-like narrowing of the left inferior pulmonary vein ostium. The narrowing measured approximately 3 mm, with poststenotic dilation. The patient had no prior history of ablation. The patient subsequently underwent segmental antral isolation of all four pulmonary veins and cavo-tricuspid isthmus ablation with bidirectional block. The diagnosis of preexisting congenital pulmonary vein stenosis had an impact on the type of ablation procedure performed (antral rather than ostial) and will affect the interpretation of postablation CT scans.