Introduction: Elimination of the initiating focus within the pulmonary vein
(PV) using radiofrequency (PF) catheter ablation is a new treatment modali
ty for treatment of drug-refractory atrial fibrillation. However, informati
on on the long-term safety of PF ablation within the PV is limited.
Methods and Results: In 102 patients with drug-refractory atrial fibrillati
on and at least one initiating focus from the PV, series transesophageal ec
hocardiography 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 i
ncreased peak Doppler flow velocity (mean 130 +/- 28 cm/sec, range 106 to 2
20), and 15 of the ablated left upper PVs (23%) had increased peak Doppler
flow velocity (mean 140 +/- 39 cm/sec, range 105 to 219). Seven patients ha
d increased peak Doppler flow velocity in both upper PVs. No factor (includ
ing age, sex, site of ablation, number of RF pulses, pulse duration, and te
mperature) 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 significant chang
e of peak and mean flow velocity and of PV diameter in sequential follow-up
studies up to 16 (209 +/- 94 days) months.
Conclusion: Focal PV stenosis is observed frequently after PF catheter abla
tion applied within the vein, but usually is without clinical significance.
However, ablation within multiple PVs might cause pulmonary hypertension a
nd should be considered a limiting factor in this procedure.