An apparatus and method for treating atrial fibrillation is described that uses a vascular stent deployed within the pulmonary veins of the left atrium. The stent may be used alone or in combination with chemical, thermal, electrical, or radioactive energy sources to ablate myocardial tissue residing in the pulmonary veins. The targeted myocardial tissue in the pulmonary veins will have been identified as the source of initiation and/or sustenance of atrial fibrillation. Ablation therapy using the pulmonary venous stent stops discharges from ectopic foci in the vein or alternatively stops impulses from reaching the left atrium. The deployed stent can then be left in place to prevent stenosis of the vein.