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This study was designed to determine whether endocardial high-frequency stimulation at the pulmonary vein (PV) antrums can localize cardiac autonomic ganglionated plexi (GP) and whether ablation at these sites can evoke a vagal response and provide a long-term benefit after PV isolation (PVI) for atrial fibrillation (AF). Radiofrequency ablation of each PV antrum was performed in 21 patients with paroxysmal AF (n = 17) or persistent (n = 4) AF. In 8 patients with paroxysmal AF, a ring electrode catheter was placed at each PV antrum. High-frequency stimulation prolonged the R-R interval in 6 of 8 patients at the left superior (LS) PV, in 3 of 8 patients at the left inferior (LI) PV, in 3 of 8 patients at the right superior (RS) PV, and in 3 of 8 patients at the right inferior (RI) PV. A decrease in sinus rate > 20% was observed in 4 of 21 patients during LS PVI, in 2 of 21 patients during RS PVI, and in 1 of 2 patients during RI PVI. Atrioventricular block or a > 5 second pause was observed in 5 of 21 patients during LS PVI. AF recurred during the follow-up period in 5 of the 16 patients (31%) who had no atrioventricular block or > 5 second pause during PVI but did not recur in 5 patients in whom atrioventricular block or a > 5 second pause developed during PVI. GP can be identified by endocardial stimulation. The AF recurrence rate is decreased when a vagal response is achieved by radiofrequency ablation. more...

Background: It was hypothesized that atrial premature contractions (APCs) originating in the pulmonary veins (PVs) or superior vena cava (SVC) can be localized by evaluating characteristics of the P wave., Methods and Results: Thirty-eight patients with paroxysmal atrial fibrillation were studied. P wave polarity and morphology of the ECGs during pacing from PVs were analyzed and compared to those of APCs originating from PVs. The P wave angle and notch in lead II during pacing from the right superior (RS) PV and SVC was compared to those of spontaneous APCs originating from those veins. A positive P wave in lead I was helpful in predicting right PV origin. A positive P wave in lead II distinguished superior PV origin. A notched P wave was helpful in predicting left PV origin. P wave polarity in lead II was positive during RSPV and SVC pacing. P waves in lead II during RSPV pacing had notching in 80%, but all P waves were smooth during SVC pacing. A P wave angle of > 40 degrees and notching in lead II showed RSPV origin., Conclusions: These criteria are helpful in selecting which of the 4 PVs should be isolated when APCs cannot be recorded after transseptal puncture. more...

Background: The pulmonary veins (PVs) are topographically complex and motile, so angiographic visualization of the PVs anatomy is limited. An imaging technique that accurately portrays the pulmonary vein (PV) anatomy would be valuable during and after catheter ablation procedures., Purpose: We investigated whether three-dimensional (3D) intracardiac echocardiography (ICE) can visualize radiofrequency (RF)-induced tissue changes after PV isolation., Methods: We performed 3D ICE studies with a 9F, 9-MHz ICE catheter after segmental or extended PV isolation. The ICE catheter was placed 3-4 cm inside the PV ostium and mounted onto a pullback device. Sequential two-dimensional (2D) images of the full length of the vein were obtained in 0.3 mm steps with cardiac and respiratory cycle gating. Each image was fed into a computer, and the aggregate data set was reconstructed into a 3D, full-motion image. RF lesion location and lesion size were studied on 67 pullback images from 29 patients., Results: The 2D and 3D reconstruction was possible for 27 left superior PVs, 13 left inferior PVs, 26 right superior PVs, and one right inferior PV. The ablation site was identified 3-7 mm inside the PV ostium, and a 1/2 - 4/5 circumferential area was ablated with no clinically relevant stenosis. No significant differences were found on the ablated area or ablation site between segmental and extensive PV isolation., Conclusion: The 2D and 3D ICE of the PVs provides detailed anatomical information of the proximal PVs, and RF-induced tissue changes in the PV wall can be visualized by ICE. more...

Background: The noninvasive methods for predicting a successful pulmonary vein isolation (PVI) have not been well described. The aim of this study was to assess the usefulness of the P-wave signal-averaged electrocardiogram (P-SAECG) in predicting the chance of a successful PVI in patients with atrial fibrillation (AF)., Methods: A P-SAECG was recorded before (pre), 1 day after, and 3-4 months after the PVI in 51 AF patients (41, paroxysmal AF; 10, persistent AF). Three-dimensional electroanatomic mapping (3D-EAM) of the right and left atria and left PVs was performed before PVI in 10 patients to analyze the biatrial conduction time (BAT)., Results: Fifteen patients suffered from AF recurrences 3 months or more after the PVI. The pre-filtered P-wave duration (FPD) was significantly longer in patients with recurrence than in those without (166.8 +/- 14.8 ms vs 145.9 +/- 12.6 ms, P < 0.0001). In both patient groups, PVI shortened the FPD, which continued for 3-4 months. Multivariate analysis revealed that a pre-FPD >150 ms was a powerful predictor for recurrence, but persistent AF, the left atrial dimension, and structural heart disease were not predictors for recurrence. 3D-EAM showed that the delayed activation point was located within the left PVs and the BAT was identical to the pre-FPD., Conclusions: The pre-FPD may strongly reflect atrial dysfunction, and thus may be useful for predicting a successful PVI. Shortening of the FPD after the PVI and similar FPD and BAT values suggest that the last component of the FPD represents the activation of the left PVs. more...