Acquired Pulmonary Vein Stenosis after Radiofrequency Catheter Ablation of Paroxysmal Atrial Fibrillation WEN-CHUNG YU, M.D., TSUI-LIEH HSU, M.D., CHING-TAI TAI, M.D., CHIN-FENG TSAI, M.D., MING-HSIUNG HSIEH, M.D., WEI-SHIANG LIN, M.D., YUNG-KUO LIN, M.D., HSUAN-MING TSAO, M.D., YU-AN DING, M.D., MAU-SONG CHANG, M.D., and SHIH-ANN CHEN, M.D. From the Division of Cardiology, Department of Medicine, National Yang-Ming University, and Taipei Veterans General Hospital, Taiwan, Republic of China PV Stenosis after AF Ablation. Introduction: Elimination of the initiating focus within the pulmo- nary vein (PV) using radiofrequency (RF) catheter ablation is a new treatment modality for treatment of drug-refractory atrial brillation. However, information on the long-term safety of RF ablation within the PV is limited. Methods and Results: In 102 patients with drug-refractory atrial brillation and at least one initiating focus from the PV, series transesophageal echocardiography was performed to monitor the effect of RF ablation on the PV. There were 66 foci in the right upper PV and 65 foci in the left upper PV. Within 3 days of ablation, 26 of the ablated right upper PVs (39%) had increased peak Doppler ow velocity (mean 130 6 28 cm/sec, range 106 to 220), and 15 of the ablated left upper PVs (23%) had increased peak Doppler ow velocity (mean 140 6 39 cm/sec, range 105 to 219). Seven patients had increased peak Doppler ow velocity in both upper PVs. No factor (including age, sex, site of ablation, number of RF pulses, pulse duration, and temperature) could predict PV stenosis after RF ablation. Three patients with stenosis of both upper PVs experienced mild dyspnea on exertion, but only one had mild increase of pulmonary pressure. There was no signicant change of peak and mean ow velocity and of PV diameter in sequential follow-up studies up to 16 (209 6 94 days) months. Conclusion: Focal PV stenosis is observed frequently after RF catheter ablation applied within the vein, but usually is without clinical signicance. However, ablation within multiple PVs might cause pulmonary hypertension and should be considered a limiting factor in this procedure. (J Cardiovasc Electrophysiol, Vol. 12, pp. 887-892, August 2001) atrial brillation, pulmonary vein stenosis, radiofrequency catheter ablation Introduction Atrial brillation (AF) is one of the most common car- diac arrhythmias. It increases cardiovascular morbidity, es- pecially embolic stroke, and mortality. 1,2 Despite progress in our understanding of atrial electrophysiology, treatment of AF remains a great challenge. High-density mapping in both animal and human studies suggested that AF is a multiwavelet reentrant tachycardia circulating in abnormal atrial substrates. 3-5 Pharmacologic and nonpharmacologic treatments devoted to modifying or eliminating the abnor- mal substrates still are not satisfactory or are limited by their serious complications. 6 Several investigators reported an alternate approach, i.e., eliminating the initiating foci of AF using catheter-based radiofrequency (RF) ablation. 7-9 Ac- cording to these reports, most of the initiating foci were located in the proximal portion of the pulmonary veins (PVs). However, the safety of RF catheter ablation per- formed around the PV ostium or within PVs is not clear. RF energy delivered around PVs has been reported to cause severe stenosis of the veins in the catheter-based maze procedure. 10 Although ablation of the foci within PVs is different from the catheter-based maze procedure, it might carry a risk of PV stenosis and requires close observation. To the best of our knowledge, this is the rst long-term follow-up report on the effect of RF catheter ablation on PVs. Clinically, the left atrium and PVs are relatively inacces- sible by traditional imaging studies because of their ana- tomic positions. Transesophageal echocardiography, with its close proximity to the left atrium and proximal PVs, can serve as a tool for monitoring the effects of RF ablation on PVs. In the present study, we used transesophageal echo- cardiography to investigate the long-term effects of RF catheter ablation on PVs. Methods The study consisted of 102 patients (89 men and 13 women; mean age 65 6 13 years, range 29 to 86) with frequent episodes (.1 episode/week) and drug-refractory (mean 2 6 1 drugs) AF who had undergone RF catheter ablation. Forty-one patients had hypertension; 6 had coro- nary artery disease; 4 had cardiomyopathy; and the remain- ing 51 patients did not have structural heart disease. Patients with initiating foci from the inferior PVs were excluded Supported in part by Grants NSC-89-2314-B-010-018 and NSC-88-2314- B-075-037 from the National Science Council and Grants VGH-89-206 and VGH-89-033 from Taipei Veterans General Hospital Taipei, Taiwan, Republic of China. Address for correspondence: Shih-Ann Chen, M.D., Division of Cardiol- ogy, Veterans General Hospital-Taipei, 201 Sec 2, Shih-Pai Road, Taipei, Taiwan, Republic of China. Fax: 886-2-2873-5656 or 886-2-2873-5875; E-mail: epsachen@ms41.hinet.net Manuscript received 17 August 2000; Accepted for publication 27 April 2001. 887