A Transthoracic Echocardiographic Follow-Up Study After Catheter Ablation of Atrial Fibrillation: Can We Detect Pulmonary Vein Stenosis by Transthoracic Echocardiography?

Background and Objectives: While pulmonary vein isolation (PVI) is an effective curative procedure for patients with atrial fibrillation (AF), pulmonary vein (PV) stenosis is a potential complication which may lead to symptoms that are often unrecognized. The aim of this study was to compare differences between ablation sites in pulmonary venous flow (PVF) measured by transthoracic Doppler echocardiography (TTE) before and after PVI. Subjects and Methods: One hundred five patients (M : F=64 : 41; mean age 56${\pm}$10 years) with paroxysmal AF (n=78) or chronic, persistent AF (n=27) were enrolled. PVI strategies consisted of ostial ablation (n=75; OA group) and antral ablation using an electroanatomic mapping system (n=30; AA group). The ostial diameter was estimated by magnetic resonance imaging (MRI) in patients with PVF ${\geq}$110 cm/sec by TTE after PVI. Results: No patient complained of PV stenosis-related symptoms. Changes in mean peak right PV systolic (-6.7${\pm}$28.1 vs. 10.9${\pm}$25.9 cm/sec, p=0.038) and diastolic (-4.1${\pm}$17.0 vs. 9.9${\pm}$25.9 cm/sec, p=0.021) flow velocities were lower in the AA group than in the OA group. Although the change in mean peak systolic flow velocity of the left PV before and after PVI in the AA group was significantly lower than the change in the OA group (-13.4${\pm}$25.1 vs. 9.2${\pm}$22.3 cm/sec, p=0.016), there was no difference in peak diastolic flow velocity. Two patients in the OA group had high PVF velocities (118 cm/sec and 133 cm/sec) on TTE, and their maximum PV stenoses measured by MRI were 62.5% and 50.0%, respectively. Conclusion: PV stenosis after PVI could be detected by TTE, and PVI by antral ablation using an electroanatomic mapping system might be safer and more useful for the prevention of PV stenosis.