Transesophageal echocardiographic assessment of pulmonary vein stenosis after radiofrequency ablation of atrial fibrillation

Background. Progressive veno-occlusive pulmonary syndrome with pulmonary hypertension as a consequence of pulmonary vein (PV) stenosis has been reported to be a major complication of PV radiofrequency (RF) ablation of refractory atrial fibrillation. The purpose of the present study was to assess the incidence of PV stenosis after successful RF catheter ablation during transesophageal echocardiographic follow-up. Methods. Twentythree patients (pts), age 44  8 years, with refractory to antiarrhythmic drugs atrial fibrillation, underwent PV isolation. Electroanatomical CARTO system was used. Transesophageal examination was performed before and three months after the procedure to rule out the presence of left atrial thrombus or patent foramen ovale, and to measure PV ostial diameter and PV flow velocities in left and right superior and inferior PV. PV stenosis was defined as a maximum PV Doppler flow velocity 110 cm/sec. Results. After ablation 16/23 pts (70%) were free from atrial fibrillation, 12/23 (52%) had no antiarrhythmic drugs, and 5/23 (22%) remained on ineffective antiarrhythmic drug therapy. 2/23 pts (8%) showed significant PV stenosis with a peak pressure gradient of 8.733.18 and 7.293.11, respectively. One pt had paroxysmal dyspnoea. Mean PV ostial diameter changed from 15 (13-21) mm before ablation to 4 (3-7) mm in pts with PV stenosis after the procedure. PV maximal flow velocity changed from baseline 60 (40-85) cm/sec to 145 (115-230) cm/sec in the presence of PV stenosis. PV stenosis was independently related to focal ablation and total energy delivery. Highest PV flow velocities after the procedure were related to smallest baseline PV diameters. Conclusion. Although the incidence of severe PV stenosis after ablation is rare, PV stenosis is nonetheless a possible complication of the procedure. Thus, estimation of PV flow before and after PV ablation is desirable.