Irreversible intrapulmonary vascular changes after pulmonary vein stenosis complicating catheter ablation for atrial fibrillation

Abstract

Pulmonary vein stenosis is a recognized complication of catheter ablation of arrhythmias emanating from the pulmonary vein; however, there is little information on secondary effects of pulmonary vein stenosis on lung tissue. A 55-year-old man with a history of paroxysmal atrial fibrillation refractory to antiarrhythmic medication had radiofrequency ablation in April 2003 and July 2003. Although these procedures were successful in resolving the patient's arrhythmia, they were complicated by the development of pulmonary vein stenosis of all four veins and pulmonary hypertension requiring patch annuloplasty of the pulmonary veins in October 2003. The patient was referred to our center for pulmonary vein stent placement in December 2003, June 2004, and August 2004, each time for recurrent hemoptysis. Due to persistent hemoptysis over the next several months, the patient underwent left lower lung lobectomy in September 2005. Microscopic examination of the lung showed marked medial thickening and intimal hyperplasia of large and small pulmonary veins and arteries, as well as focal organizing thrombi in the small arteries. The lung tissue showed extensive hemosiderin deposition indicative of prior hemorrhage. Chronic pulmonary vein stenosis after radiofrequency ablation of atrial fibrillation results in irreversible venous and arterial morphologic changes throughout the lung, including areas both close to, and remote from, the site of catheter ablation. Because there are persistent pathological changes remote from the ablation site causing the pulmonary hypertension, stenting the site of ablation to reopen large pulmonary veins may not be effective in treating the pulmonary hypertension.